avatarr-parser 0.1.0

// Ported from Sonarr v4.0.17.2952 (97e85a90):
//   src/NzbDrone.Core/Parser/QualityParser.cs

use once_cell::sync::Lazy;
use regex::Regex;

/// Source-detection regex constants ported from `QualityParser.cs`.
///
/// These mirror the C# `private static readonly Regex` declarations at lines
/// 17 to 66 of `QualityParser.cs`. The Rust `regex` crate is RE2-based and
/// does not support backreferences or lookarounds; where a C# pattern uses
/// either, the constant here is a relaxed superset and a sibling helper
/// function applies the missing constraint in code post-match. Each such
/// case is documented inline above the affected `Lazy<Regex>` declaration.
pub mod regexes {
    use super::{Lazy, Regex};

    /// Source-class detector. Ported from `QualityParser.cs:17-30`.
    ///
    /// The C# pattern uses three negative lookarounds inside the `bluray` and
    /// `webdl` branches:
    ///
    /// 1. `BD(?!$)` (bluray branch). Bare `BD` only counts when not at end of
    ///    string. Rust workaround: relaxed to `BD`; `match_source` rejects a
    ///    `bluray` match whose entire captured text is `BD` and ends at the
    ///    input boundary.
    /// 2. `(?-i:WEB)$` (webdl branch). Case-sensitive uppercase `WEB` at end
    ///    of input. Rust regex DOES support `(?-i:...)` flag-disable groups,
    ///    so this is ported verbatim.
    /// 3. `(?:AMZN|NF|DP)[. -]WEB[. -](?!Rip)` (webdl branch). Provider tag
    ///    followed by `WEB` and a separator that is not `Rip`. Rust workaround:
    ///    drops the `(?!Rip)` and wraps the provider alternative in a nested
    ///    named sub-capture `(?P<provider_web>...)`. `match_source` then gates
    ///    the post-match `(?!Rip)` filter on `provider_web.is_some()`,
    ///    structurally identifying which alternation branch fired rather than
    ///    relying on alternation order or prefix heuristics.
    ///
    /// Callers reach a fully-correct match through [`super::match_source`];
    /// the raw `SOURCE_REGEX` is exported for tests that want to assert which
    /// branch the alternation hit (named groups: `bluray`, `webdl`, `webrip`,
    /// `hdtv`, `bdrip`, `brrip`, `dvd`, `dsr`, `pdtv`, `sdtv`, `tvrip`).
    pub static SOURCE_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(
            r"(?ix)
            \b(?:
                (?P<bluray>BluRay|Blu-Ray|HD-?DVD|BDMux|BD)|
                (?P<webdl>
                    WEB[-_.\x20]DL(?:mux)?|WEBDL|AmazonHD|AmazonSD|iTunesHD|MaxdomeHD|NetflixU?HD|WebHD|HBOMaxHD|DisneyHD|
                    [.\x20]WEB[.\x20](?:[xh][ .]?26[45]|AVC|HEVC|DDP?5[. ]1)|
                    [.\x20](?-i:WEB)$|
                    (?:720|1080|2160)p[-.\x20]WEB[-.\x20]|
                    [-.\x20]WEB[-.\x20](?:720|1080|2160)p|
                    \b\s/\sWEB\s/\s\b|
                    (?P<provider_web>(?:AMZN|NF|DP)[.\x20-]WEB[.\x20-])
                )|
                (?P<webrip>WebRip|Web-Rip|WEBMux)|
                (?P<hdtv>HDTV)|
                (?P<bdrip>BDRip|BDLight)|
                (?P<brrip>BRRip)|
                (?P<dvd>DVD|DVDRip|NTSC|PAL|xvidvd)|
                (?P<dsr>WS[-_.\x20]DSR|DSR)|
                (?P<pdtv>PDTV)|
                (?P<sdtv>SDTV)|
                (?P<tvrip>TVRip)
            )(?:\b|$|[\x20.])",
        )
        .expect("SOURCE_REGEX must compile")
    });

    /// `RawHD` / `Raw-HD` / `Raw_HD` / `Raw.HD` / `Raw HD` detector. Ported
    /// from `QualityParser.cs:32-33`.
    pub static RAW_HD_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)\b(?P<rawhd>RawHD|Raw[-_. ]HD)\b").expect("RAW_HD_REGEX must compile")
    });

    /// `MPEG2` / `MPEG-2` / `MPEG_2` / `MPEG.2` / `MPEG 2` detector. Ported
    /// from `QualityParser.cs:35`. Note: the C# pattern is **case-sensitive**
    /// (no `RegexOptions.IgnoreCase`), so we omit the `(?i)` flag here.
    pub static MPEG2_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"\b(?P<mpeg2>MPEG[-_. ]?2)\b").expect("MPEG2_REGEX must compile"));

    /// Remux detector. Ported from `QualityParser.cs:66`.
    ///
    /// The C# pattern declares the same group name `(?<remux>...)` twice in an
    /// alternation. .NET allows that; Rust's `regex` crate rejects duplicate
    /// names within a single pattern. To preserve identical match semantics
    /// while staying compilable, the second branch's group is renamed
    /// `remux_post`. Callers should treat a hit on EITHER `remux` or
    /// `remux_post` as a positive Remux signal; `super::match_remux` exposes
    /// that contract directly.
    pub static REMUX_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(
            r"(?i)(?:[_. ]|\d{4}p-|\bHybrid-)(?P<remux>(?:(BD|UHD)[-_. ]?)?Remux)\b|(?P<remux_post>(?:(BD|UHD)[-_. ]?)?Remux[_. ]\d{4}p)",
        )
        .expect("REMUX_REGEX must compile")
    });

    /// Anime-Bluray detector. Ported from `QualityParser.cs:61`.
    ///
    /// The C# pattern uses paired lookarounds for the bare `bd` branch:
    /// `(?<=[-_. (\[])bd(?=[-_. )\]])`. Rust's `regex` crate does not support
    /// lookarounds, so the constant here is the relaxed superset
    /// `bd(?:720|1080|2160)|bd`. Callers must reach a fully-correct match
    /// through [`super::matches_anime_bluray`], which applies the surround
    /// check in code on bare `bd` candidates.
    pub static ANIME_BLURAY_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)bd(?:720|1080|2160)|bd").expect("ANIME_BLURAY_REGEX must compile")
    });

    /// Anime-WEB-DL detector. Ported from `QualityParser.cs:62`.
    pub static ANIME_WEBDL_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)\[WEB\]|[\[(]WEB[ .]").expect("ANIME_WEBDL_REGEX must compile")
    });

    /// Resolution detector. Ported from `QualityParser.cs:49-50`.
    ///
    /// Named groups: `R360p`, `R480p`, `R540p`, `R576p`, `R720p`, `R1080p`,
    /// `R2160p`. Case-insensitive (`IgnoreCase` in C# → `(?i)` flag here).
    ///
    /// Cross-checked against C#: every alternative branch, including the
    /// `4kto1080p` downscaled-UHD token on the `R1080p` branch, is reproduced
    /// verbatim. The one place this port deliberately differs from the m50
    /// plan-spec draft is the `R2160p` branch's 4K alternatives: the plan
    /// drafted `4kto2160p`, but C# actually carries
    /// `4k[-_. ](?:UHD|HEVC|BD|H265)|(?:UHD|HEVC|BD|H265)[-_. ]4k`. C# is
    /// authoritative per the m50 standing rules, so the port mirrors C#.
    /// The Rust `regex` crate accepts the pattern as-is, with every named
    /// group unique and no lookarounds.
    pub static RESOLUTION_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(
            r"(?i)\b(?:(?P<R360p>360p)|(?P<R480p>480p|480i|640x480|848x480)|(?P<R540p>540p)|(?P<R576p>576p)|(?P<R720p>720p|1280x720|960p)|(?P<R1080p>1080p|1920x1080|1440p|FHD|1080i|4kto1080p)|(?P<R2160p>2160p|3840x2160|4k[-_. ](?:UHD|HEVC|BD|H265)|(?:UHD|HEVC|BD|H265)[-_. ]4k))\b",
        )
        .expect("RESOLUTION_REGEX must compile")
    });

    /// Alternative resolution detector for releases that omit a numeric
    /// resolution token. Ported from `QualityParser.cs:53-54`.
    ///
    /// The C# pattern declares `(?<R2160p>...)` twice in an alternation
    /// (`(?<R2160p>UHD)\b|(?<R2160p>\[4K\])`). .NET allows duplicate group
    /// names and merges their captures; Rust's `regex` crate rejects this. To
    /// preserve identical match semantics while staying compilable, the second
    /// branch is renamed `R2160p_alt`. Callers should treat a hit on EITHER
    /// `R2160p` or `R2160p_alt` as a positive 2160p signal;
    /// [`super::matches_alternative_resolution`] coalesces both branches into
    /// a single boolean.
    pub static ALTERNATIVE_RESOLUTION_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)\b(?P<R2160p>UHD)\b|(?P<R2160p_alt>\[4K\])")
            .expect("ALTERNATIVE_RESOLUTION_REGEX must compile")
    });

    /// Codec detector. Ported from `QualityParser.cs:56-57`.
    ///
    /// Named groups: `x264`, `h264`, `xvidhd`, `xvid`, `divx`. Case-insensitive
    /// (`IgnoreCase` in C# → `(?i)` flag here). Note that the C# pattern uses
    /// the literal `Xvid` (no hyphen variant), so this port matches `Xvid` and
    /// `xvid` (case-insensitive) but NOT `X-vid`. The plan-spec drafted
    /// `X-?vid`; C# is authoritative per the m50 standing rules, so we keep
    /// the C# form.
    pub static CODEC_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(
            r"(?i)\b(?:(?P<x264>x264)|(?P<h264>h264)|(?P<xvidhd>XvidHD)|(?P<xvid>Xvid)|(?P<divx>divx))\b",
        )
        .expect("CODEC_REGEX must compile")
    });

    /// `HD-TV` / `SD-TV` alternative-form detector. Ported from
    /// `QualityParser.cs:59`. Named groups: `hdtv`, `sdtv`. Case-insensitive.
    pub static OTHER_SOURCE_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)(?P<hdtv>HD[-_. ]TV)|(?P<sdtv>SD[-_. ]TV)")
            .expect("OTHER_SOURCE_REGEX must compile")
    });

    /// `hr-ws` (high-def PDTV) detector. Ported from `QualityParser.cs:64`.
    /// Case-insensitive.
    pub static HIGH_DEF_PDTV_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"(?i)hr[-_. ]ws").expect("HIGH_DEF_PDTV_REGEX must compile"));

    /// PROPER detector. Ported from `QualityParser.cs:37-38`.
    /// Named group: `proper`. Case-insensitive.
    pub static PROPER_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"(?i)\b(?P<proper>proper)\b").expect("PROPER_REGEX must compile"));

    /// REPACK / RERIP detector. Ported from `QualityParser.cs:40-41`. Matches
    /// `repack`, `repack1`, `repack2`, ..., `rerip`, `rerip1`, `rerip2`, etc.
    /// Named group: `repack`. Case-insensitive.
    pub static REPACK_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(r"(?i)\b(?P<repack>repack\d?|rerip\d?)\b").expect("REPACK_REGEX must compile")
    });

    /// Explicit version-marker detector. Ported from `QualityParser.cs:43-44`.
    ///
    /// The C# pattern declares the same `<version>` named group on FIVE
    /// alternation branches:
    ///
    /// 1. `\d[-._ ]?v(?<version>\d)[-._ ]` (e.g. `1v2.`, `01-v2_`)
    /// 2. `\[v(?<version>\d)\]` (e.g. `[v2]`)
    /// 3. `repack(?<version>\d)` (e.g. `repack2`)
    /// 4. `rerip(?<version>\d)` (e.g. `rerip3`)
    /// 5. `(?:480|576|720|1080|2160)p[._ ]v(?<version>\d)` (e.g. `1080p.v2`)
    ///
    /// .NET allows duplicate names and merges captures; Rust's `regex` crate
    /// rejects them. We rename branches 2-5 to `version2`, `version3`,
    /// `version4`, `version5`. Callers should walk all five names and pick
    /// the first hit:
    ///
    /// ```ignore
    /// caps.name("version")
    ///     .or_else(|| caps.name("version2"))
    ///     .or_else(|| caps.name("version3"))
    ///     .or_else(|| caps.name("version4"))
    ///     .or_else(|| caps.name("version5"))
    /// ```
    ///
    /// T6's modifier cascade owns that walk; the helper is intentionally not
    /// added in T5 because the cascade has additional decision logic that
    /// would be split awkwardly. Case-insensitive (`IgnoreCase` in C# → `(?i)`
    /// flag here).
    pub static VERSION_REGEX: Lazy<Regex> = Lazy::new(|| {
        Regex::new(
            r"(?i)\d[-._ ]?v(?P<version>\d)[-._ ]|\[v(?P<version2>\d)\]|repack(?P<version3>\d)|rerip(?P<version4>\d)|(?:480|576|720|1080|2160)p[._ ]v(?P<version5>\d)",
        )
        .expect("VERSION_REGEX must compile")
    });

    /// REAL detector. Ported from `QualityParser.cs:46-47`.
    ///
    /// **Case-sensitive intentionally.** The C# pattern carries
    /// `RegexOptions.Compiled` only (no `IgnoreCase`), so only uppercase
    /// `REAL` matches. We omit the `(?i)` flag here to mirror C# faithfully.
    pub static REAL_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"\b(?P<real>REAL)\b").expect("REAL_REGEX must compile"));
}

use regexes::*;

/// Source-class signal extracted from a single `SOURCE_REGEX` candidate that
/// has passed all post-match lookaround filters. Carries which named group
/// hit (so callers can route to the correct `Quality` variant) plus the
/// matched substring (for debug logging and round-trip tests).
#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) struct SourceMatch<'a> {
    pub group: SourceGroup,
    pub matched: &'a str,
}

/// Which named alternative inside `SOURCE_REGEX` matched.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub(crate) enum SourceGroup {
    Bluray,
    Webdl,
    Webrip,
    Hdtv,
    Bdrip,
    Brrip,
    Dvd,
    Dsr,
    Pdtv,
    Sdtv,
    Tvrip,
}

/// Classify a single `SOURCE_REGEX` `Captures` into a `SourceMatch`, or
/// `None` if the capture fails the C# lookaround filters.
///
/// Filters applied (mirroring `QualityParser.cs:17-30`):
///
/// 1. `bluray` branch: a bare `BD` that ends at the input boundary is
///    rejected (`BD(?!$)` in C#).
/// 2. `webdl` branch: an `(?:AMZN|NF|DP)[. -]WEB[. -]` capture that is
///    followed in the input by `Rip` (case-insensitive) is rejected
///    (`(?!Rip)` in C#). Identified structurally via the nested
///    `provider_web` sub-capture rather than a prefix check on the
///    outer match. Robust against future alternation reordering.
fn classify_source_capture<'a>(s: &'a str, caps: &regex::Captures<'a>) -> Option<SourceMatch<'a>> {
    let (group, mat) = if let Some(m) = caps.name("bluray") {
        (SourceGroup::Bluray, m)
    } else if let Some(m) = caps.name("webdl") {
        (SourceGroup::Webdl, m)
    } else if let Some(m) = caps.name("webrip") {
        (SourceGroup::Webrip, m)
    } else if let Some(m) = caps.name("hdtv") {
        (SourceGroup::Hdtv, m)
    } else if let Some(m) = caps.name("bdrip") {
        (SourceGroup::Bdrip, m)
    } else if let Some(m) = caps.name("brrip") {
        (SourceGroup::Brrip, m)
    } else if let Some(m) = caps.name("dvd") {
        (SourceGroup::Dvd, m)
    } else if let Some(m) = caps.name("dsr") {
        (SourceGroup::Dsr, m)
    } else if let Some(m) = caps.name("pdtv") {
        (SourceGroup::Pdtv, m)
    } else if let Some(m) = caps.name("sdtv") {
        (SourceGroup::Sdtv, m)
    } else if let Some(m) = caps.name("tvrip") {
        (SourceGroup::Tvrip, m)
    } else {
        return None;
    };

    // Filter 1: bluray bare-BD-at-end-of-input rejection (C# `BD(?!$)`).
    if group == SourceGroup::Bluray
        && mat.as_str().eq_ignore_ascii_case("BD")
        && mat.end() == s.len()
    {
        return None;
    }

    // Filter 2: webdl provider-tag-followed-by-Rip rejection
    // (C# `(?:AMZN|NF|DP)[. -]WEB[. -](?!Rip)`). Gated on the nested
    // `provider_web` sub-capture so we apply the (?!Rip) filter only when
    // that exact alternation branch fired, independent of alternation
    // order or text-prefix heuristics on the outer match.
    if group == SourceGroup::Webdl && caps.name("provider_web").is_some() {
        let tail = &s[mat.end()..];
        if tail.len() >= 3 && tail.as_bytes()[..3].eq_ignore_ascii_case(b"Rip") {
            // Consumed-iterator pattern: the webdl branch consumed the WEB token,
            // so the webrip branch can never fire. Synthesize the Webrip match
            // to mirror C#'s backtrack semantics.
            return Some(SourceMatch {
                group: SourceGroup::Webrip,
                matched: mat.as_str(),
            });
        }
    }

    Some(SourceMatch {
        group,
        matched: mat.as_str(),
    })
}

/// Find the first source-class match in `s`, applying the lookahead filters
/// that Rust regex cannot express directly. Returns `None` if no candidate
/// satisfies the C# semantics.
///
/// See [`classify_source_capture`] for the filter list.
///
/// Test-only: the production cascade uses [`match_source_last`] (last-wins
/// semantics, see C# `QualityParser.cs:115`). This first-match form exists
/// to pin the C# regex's per-branch alternation behaviour from the test
/// suite without leaking a never-used helper into the production build.
#[cfg(test)]
pub(crate) fn match_source(s: &str) -> Option<SourceMatch<'_>> {
    for caps in SOURCE_REGEX.captures_iter(s) {
        if let Some(m) = classify_source_capture(s, &caps) {
            return Some(m);
        }
    }
    None
}

/// Find the LAST source-class match in `s`, mirroring C#'s
/// `sourceMatches.OfType<Match>().LastOrDefault()` at `QualityParser.cs:115`.
///
/// The cascade uses last-match-wins semantics: a release like
/// `Movie.HDTV.Repack.BluRay.x264` classifies as bluray, not hdtv, because
/// `BluRay` appears AFTER `HDTV` in the string. C# achieves this with
/// `Regex.Matches(...).OfType<Match>().LastOrDefault()`; we mirror it by
/// walking every candidate from `captures_iter` and keeping the last that
/// passes [`classify_source_capture`]'s filters.
///
/// Returns `None` only when no candidate in the entire string satisfies the
/// post-match lookaround filters. A candidate that is rejected by a filter
/// is skipped; an earlier accepted candidate may still be returned if no
/// later candidate passes.
pub(crate) fn match_source_last(s: &str) -> Option<SourceMatch<'_>> {
    let mut last: Option<SourceMatch<'_>> = None;
    for caps in SOURCE_REGEX.captures_iter(s) {
        if let Some(m) = classify_source_capture(s, &caps) {
            last = Some(m);
        }
    }
    last
}

/// Anime-Bluray detection respecting C#'s lookaround semantics.
///
/// The relaxed `ANIME_BLURAY_REGEX` matches `bd720`/`bd1080`/`bd2160`
/// directly, and also matches a bare `bd` anywhere in the input. C# only
/// counts a bare `bd` when it is surrounded by one of `[-_. (\[]` on the left
/// and one of `[-_. )\]]` on the right. This function applies that surround
/// check in code, returning `true` on the first candidate that passes.
///
/// Bare `bd` requires a separator on both sides. Bare `bd` at start- or
/// end-of-input does NOT match, matching C#'s paired
/// `(?<=[-_. (\[])bd(?=[-_. )\]])` lookaround semantics where the
/// lookbehind/lookahead fails at the input boundary.
pub(crate) fn matches_anime_bluray(s: &str) -> bool {
    for m in ANIME_BLURAY_REGEX.find_iter(s) {
        let matched = m.as_str();
        if matched.len() == 2 {
            // Bare `bd`: check the C# surround constraint.
            let bytes = s.as_bytes();
            let start = m.start();
            let end = m.end();
            // Note: `as_bytes().get(start - 1)` returns a single byte at a UTF-8 boundary.
            // For multi-byte chars (e.g. 'é'), the read returns a continuation byte
            // (0x80..=0xBF) which is outside the ASCII separator set, so the surround
            // check correctly rejects non-ASCII surrounds.
            let before_ok = start > 0
                && matches!(
                    bytes.get(start - 1),
                    Some(b'-' | b'_' | b'.' | b' ' | b'(' | b'[')
                );
            let after_ok = end < s.len()
                && matches!(
                    bytes.get(end),
                    Some(b'-' | b'_' | b'.' | b' ' | b')' | b']')
                );
            if before_ok && after_ok {
                return true;
            }
        } else {
            // `bd720` / `bd1080` / `bd2160`: always counts.
            return true;
        }
    }
    false
}

/// Remux detector that merges the two same-named C# capture groups
/// (`remux` and `remux_post` in the Rust port) into a single signal.
///
/// Returns `Some(matched_text)` on the first hit, `None` otherwise. Callers
/// that need positional information can fall back to `REMUX_REGEX` directly;
/// this helper is the canonical "is this a remux release?" gate.
pub(crate) fn match_remux(s: &str) -> Option<&str> {
    for caps in REMUX_REGEX.captures_iter(s) {
        if let Some(m) = caps.name("remux").or_else(|| caps.name("remux_post")) {
            return Some(m.as_str());
        }
    }
    None
}

/// Alternative-resolution detector that merges the two same-named C# capture
/// groups (`R2160p` and `R2160p_alt` in the Rust port) into a single boolean
/// signal.
///
/// Returns `true` if either branch fires, mirroring C#'s
/// `(?<R2160p>UHD)\b|(?<R2160p>\[4K\])` semantics where both alternatives are
/// recorded under the same name.
pub(crate) fn matches_alternative_resolution(s: &str) -> bool {
    ALTERNATIVE_RESOLUTION_REGEX
        .captures_iter(s)
        .any(|caps| caps.name("R2160p").is_some() || caps.name("R2160p_alt").is_some())
}

/// Resolution detector mirroring C#'s `ParseResolution`
/// (`QualityParser.cs:600-651`).
///
/// Walks `RESOLUTION_REGEX`'s named groups in C# evaluation order
/// (R360p, R480p, R540p, R576p, R720p, R1080p, R2160p) and returns the first
/// hit. If no main-regex group fires, falls back to
/// [`matches_alternative_resolution`] to detect the `UHD` / `[4K]` tokens that
/// C#'s `AlternativeResolutionRegex` covers; either alternative-regex branch
/// counts as `R2160p`. Returns `Resolution::Unknown` if neither regex matches.
///
/// **Group-order note.** The C# code checks groups starting from the smallest
/// resolution upward (R360p first, R2160p last). The named groups in
/// `RESOLUTION_REGEX` are mutually exclusive within a single capture (an
/// alternation only fires one branch), so the order does not affect behaviour
/// for any input the regex can match. We mirror the C# walk order verbatim
/// to keep the port reviewable against the source.
fn detect_resolution(name: &str) -> crate::quality::Resolution {
    use crate::quality::Resolution;

    if let Some(caps) = RESOLUTION_REGEX.captures(name) {
        if caps.name("R360p").is_some() {
            return Resolution::R360p;
        }
        if caps.name("R480p").is_some() {
            return Resolution::R480p;
        }
        if caps.name("R540p").is_some() {
            return Resolution::R540p;
        }
        if caps.name("R576p").is_some() {
            return Resolution::R576p;
        }
        if caps.name("R720p").is_some() {
            return Resolution::R720p;
        }
        if caps.name("R1080p").is_some() {
            return Resolution::R1080p;
        }
        if caps.name("R2160p").is_some() {
            return Resolution::R2160p;
        }
    }

    if matches_alternative_resolution(name) {
        return Resolution::R2160p;
    }

    Resolution::Unknown
}

/// `Quality.Source` reverse lookup. Mirrors the C# constructor pairs in
/// `Quality.cs:77-124` where each `Quality` static is paired with a
/// `QualitySource` argument.
///
/// Used by [`parse_quality_name`]'s resolution-only fallback to derive a
/// `QualitySource` from the extension-derived `Quality`, mirroring C#
/// `QualityParser.cs:444` (`source = quality.Source`).
fn quality_source(q: crate::quality::Quality) -> crate::quality::QualitySource {
    use crate::quality::{Quality, QualitySource};
    match q {
        Quality::Unknown => QualitySource::Unknown,
        Quality::Sdtv => QualitySource::Television,
        Quality::Hdtv720p => QualitySource::Television,
        Quality::Hdtv1080p => QualitySource::Television,
        Quality::Hdtv2160p => QualitySource::Television,
        Quality::RawHd => QualitySource::TelevisionRaw,
        Quality::Webdl480p => QualitySource::Web,
        Quality::Webdl720p => QualitySource::Web,
        Quality::Webdl1080p => QualitySource::Web,
        Quality::Webdl2160p => QualitySource::Web,
        Quality::Webrip480p => QualitySource::WebRip,
        Quality::Webrip720p => QualitySource::WebRip,
        Quality::Webrip1080p => QualitySource::WebRip,
        Quality::Webrip2160p => QualitySource::WebRip,
        Quality::Dvd => QualitySource::Dvd,
        Quality::Bluray480p => QualitySource::Bluray,
        Quality::Bluray576p => QualitySource::Bluray,
        Quality::Bluray720p => QualitySource::Bluray,
        Quality::Bluray1080p => QualitySource::Bluray,
        Quality::Bluray2160p => QualitySource::Bluray,
        Quality::Bluray1080pRemux => QualitySource::BlurayRaw,
        Quality::Bluray2160pRemux => QualitySource::BlurayRaw,
    }
}

/// File-extension to `Quality` lookup. Ports
/// `MediaFileExtensions.cs:9-71` + `GetQualityForExtension` (lines 76-84).
///
/// Returns `Quality::Unknown` for any extension not in the table OR an empty
/// extension. The C# wrapper at `QualityParser.cs:82-95` and the inline
/// extension lookup at `:437-451` both use this; the inline path uses Sonarr's
/// `string.GetPathExtension()` (`PathExtensions.cs:74-83`), which is a bare
/// `LastIndexOf('.')` slice (no path-validity checks).
///
/// Comparison is ASCII-case-insensitive to match
/// `StringComparer.OrdinalIgnoreCase` at `MediaFileExtensions.cs:13`.
fn quality_for_extension(extension: &str) -> crate::quality::Quality {
    use crate::quality::Quality;
    // C# MediaFileExtensions.cs:9-71. Pairs are (extension-with-dot, Quality).
    const TABLE: &[(&str, Quality)] = &[
        // Unknown
        (".webm", Quality::Unknown),
        // SDTV
        (".m4v", Quality::Sdtv),
        (".3gp", Quality::Sdtv),
        (".nsv", Quality::Sdtv),
        (".ty", Quality::Sdtv),
        (".strm", Quality::Sdtv),
        (".rm", Quality::Sdtv),
        (".rmvb", Quality::Sdtv),
        (".m3u", Quality::Sdtv),
        (".ifo", Quality::Sdtv),
        (".mov", Quality::Sdtv),
        (".qt", Quality::Sdtv),
        (".divx", Quality::Sdtv),
        (".xvid", Quality::Sdtv),
        (".bivx", Quality::Sdtv),
        (".nrg", Quality::Sdtv),
        (".pva", Quality::Sdtv),
        (".wmv", Quality::Sdtv),
        (".asf", Quality::Sdtv),
        (".asx", Quality::Sdtv),
        (".ogm", Quality::Sdtv),
        (".ogv", Quality::Sdtv),
        (".m2v", Quality::Sdtv),
        (".avi", Quality::Sdtv),
        (".bin", Quality::Sdtv),
        (".dat", Quality::Sdtv),
        (".dvr-ms", Quality::Sdtv),
        (".mpg", Quality::Sdtv),
        (".mpeg", Quality::Sdtv),
        (".mp4", Quality::Sdtv),
        (".avc", Quality::Sdtv),
        (".vp3", Quality::Sdtv),
        (".svq3", Quality::Sdtv),
        (".nuv", Quality::Sdtv),
        (".viv", Quality::Sdtv),
        (".dv", Quality::Sdtv),
        (".fli", Quality::Sdtv),
        (".flv", Quality::Sdtv),
        (".wpl", Quality::Sdtv),
        // DVD
        (".img", Quality::Dvd),
        (".iso", Quality::Dvd),
        (".vob", Quality::Dvd),
        // HD
        (".mkv", Quality::Hdtv720p),
        (".ts", Quality::Hdtv720p),
        (".wtv", Quality::Hdtv720p),
        // Bluray
        (".m2ts", Quality::Bluray720p),
    ];

    if extension.is_empty() {
        return Quality::Unknown;
    }
    for (ext, q) in TABLE {
        if extension.eq_ignore_ascii_case(ext) {
            return *q;
        }
    }
    Quality::Unknown
}

/// Sonarr's `string.GetPathExtension()` from
/// `NzbDrone.Common/Extensions/PathExtensions.cs:74-83`.
///
/// Returns the substring from the LAST `.` to end-of-string, INCLUDING the
/// dot. Returns an empty string if there is no `.` or if the dot is the final
/// character. This is NOT `Path.GetExtension` semantics; it does no path
/// validation, so it picks the trailing token from any string regardless of
/// platform path syntax. The resolution-only fallback at C#
/// `QualityParser.cs:439` calls this helper, which is why a release name like
/// `Movie.2020.1080p.x264.mkv` will yield `.mkv` even though the filename
/// portion has no directory structure.
fn get_path_extension(path: &str) -> &str {
    if let Some(idx) = path.rfind('.')
        && idx + 1 < path.len()
    {
        return &path[idx..];
    }
    ""
}

/// ASCII case-insensitive substring search, mirroring .NET's
/// `string.ContainsIgnoreCase`.
///
/// C#'s `ContainsIgnoreCase` is a culture-aware match by default, but the
/// Sonarr extension method (`Extensions/StringExtensions.cs`) implements it as
/// `IndexOf(value, StringComparison.OrdinalIgnoreCase) >= 0`. Ordinal-IgnoreCase
/// folds only the ASCII A-Z / a-z range; non-ASCII code points round-trip
/// unchanged. The Rust port mirrors that contract via
/// [`str::eq_ignore_ascii_case`] on byte-aligned windows.
fn contains_ignore_ascii_case(haystack: &str, needle: &str) -> bool {
    let n = needle.len();
    if n == 0 {
        return true;
    }
    let h = haystack.as_bytes();
    if h.len() < n {
        return false;
    }
    h.windows(n)
        .any(|w| w.eq_ignore_ascii_case(needle.as_bytes()))
}

/// Quality-cascade entry-point. Ported from `QualityParser.cs:100-598`
/// (`ParseQualityName`).
///
/// **Duties.**
///
/// 1. Normalise: `name.Replace('_', ' ').Trim()` and `name.Trim()` for the raw
///    side, mirroring C#'s twin `Trim()` calls at `QualityParser.cs:77` and
///    `QualityParser.cs:102`.
/// 2. Run `parse_quality_modifiers` against both raw and normalised name to
///    populate `Revision`. Modifiers that fire also set
///    `revision_detection_source = Name`.
/// 3. RawHD short-circuit (C# line 105): return `Quality::RawHd` with
///    `source_detection_source = resolution_detection_source = Name`.
/// 4. Source-to-quality cascade (C# lines 114-318): take the LAST source
///    match, pair with the parsed resolution + codec + remux signals, and
///    route to a concrete `Quality` variant. Branches:
///
///    - `bluray`: codec(xvid|divx) -> 480p, else by-resolution
///      (2160 / 1080 / 576 / {360, 480, 540}); remux+resolution!=720 -> 1080pRemux;
///      else 720p.
///    - `webdl`: by-resolution (2160 / 1080 / 720); raw-name `[WEBDL]` -> 720p;
///      else 480p.
///    - `webrip`: by-resolution (2160 / 1080 / 720); else 480p.
///    - `hdtv`: MPEG2 -> RawHD; else by-resolution; raw-name `[HDTV]` -> 720p;
///      else SDTV.
///    - `bdrip` / `brrip`: by-resolution (720 / 1080 / 2160); else 480p.
///    - `dvd`: DVD always.
///    - `pdtv` / `sdtv` / `dsr` / `tvrip`: 1080p match -> Hdtv1080p;
///      720p match -> Hdtv720p; HighDefPdtv (`hr-ws`) -> Hdtv720p; else SDTV.
///
///    Provenance flags (`source_detection_source`, `resolution_detection_source`)
///    are populated according to the C# rules: `source_detection_source` is set
///    to `Name` whenever a sourceMatch fires; `resolution_detection_source` is
///    set to `Name` when the resolution-regex hit (line 122) or, in the
///    pdtv-cluster branch, when the `ContainsIgnoreCase` substring fallback
///    fires (line 308's `HighDefPdtvRegex` path).
///
/// **Fallthrough cascade (T8).** When no source match fires, the following
/// fallbacks run in C# order, each returning on a hit:
///
/// - **Sourceless remux** (C# 320-347): `remuxMatch && resolution != Unknown`,
///   dispatched per resolution. SourceDetectionSource is explicitly `Unknown`
///   here per C# line 322.
/// - **Anime-bluray** (C# 349-390): `AnimeBlurayRegex` hits, resolution-routed
///   (480/1080/2160/720 defaults). 480p in this branch maps to `Quality::Dvd`
///   per C# line 359.
/// - **Anime-webdl** (C# 392-424): `AnimeWebDlRegex` hits, resolution-routed.
/// - **Resolution-only** (C# 426-497): `resolution != Unknown`. Derives a
///   `QualitySource` from `remuxMatch` (`BlurayRaw`) OR from the file
///   extension via [`quality_for_extension`] + [`quality_source`], then
///   dispatches via `find_by_source_and_resolution`. Unknown source falls
///   back to Television-class defaults (Hdtv2160p / Hdtv1080p / Hdtv720p / Sdtv).
/// - **x264-SDTV** (C# 499-504): bare `x264` with no other signal -> `Sdtv`.
/// - **Pixel-tag fallbacks** (C# 506-560): literal `848x480`, `1280x720`,
///   `1920x1080` substrings, optionally combined with `dvd` / `bluray` markers.
/// - **Bare-bluray-resolution** (C# 562-587): literal `bluray720p` /
///   `bluray1080p` / `bluray2160p` -> `Bluray720p` / `Bluray1080p` / `Bluray2160p`.
/// - **`OtherSourceMatch`** (C# 589-595, 653-672): `OTHER_SOURCE_REGEX` hit
///   (`HD-TV` / `SD-TV` alternative form) -> `Hdtv720p` / `Sdtv`.
///
/// **Most callers want [`parse_quality`] instead.** That wrapper adds the
/// extension-fallback behaviour from `QualityParser.cs:81-95` on top of
/// `parse_quality_name`'s output. Use `parse_quality_name` directly only
/// when you specifically want to bypass the extension lookup (e.g.,
/// text-only parsing, no file path implied). This split mirrors C#'s
/// `ParseQuality` (public) vs `ParseQualityName` (test-seam) shape.
pub fn parse_quality_name(name: &str) -> crate::quality::QualityModel {
    use crate::quality::{
        Quality, QualityDetectionSource, QualityModel, QualitySource, Resolution,
    };

    // C# `QualityParser.cs:77` (`name.Trim()` in ParseQuality, the outer
    // wrapper). The plan delegates this trim to ParseQualityName because the
    // Rust port has only one entry point. Apply to the raw input so the
    // `[WEBDL]` / `[HDTV]` substring checks against `name` see the trimmed
    // string just like C#.
    let raw = name.trim();

    // C# `QualityParser.cs:102`: `name.Replace('_', ' ').Trim()`.
    let normalized = raw.replace('_', " ");
    let normalized = normalized.trim();

    let (revision, revision_detection_source) = parse_quality_modifiers(raw, normalized);

    if RAW_HD_REGEX.is_match(normalized) {
        return QualityModel {
            quality: Quality::RawHd,
            revision,
            source_detection_source: QualityDetectionSource::Name,
            resolution_detection_source: QualityDetectionSource::Name,
            revision_detection_source,
        };
    }

    // C# QualityParser.cs:114-118: gather the per-name signals in one pass.
    // - sourceMatch: LAST sourceMatch wins (line 115's LastOrDefault).
    // - resolution: ParseResolution, our `detect_resolution` helper.
    // - codec_*: x264 / xvid / divx / xvidhd / h264 named groups.
    // - remux_match: REMUX_REGEX hit, gated through `match_remux`.
    let source_match = match_source_last(normalized);
    let resolution = detect_resolution(normalized);
    let codec_caps = CODEC_REGEX.captures(normalized);
    let codec_xvid = codec_caps.as_ref().and_then(|c| c.name("xvid")).is_some();
    let codec_divx = codec_caps.as_ref().and_then(|c| c.name("divx")).is_some();
    let remux_match = match_remux(normalized).is_some();

    // C# QualityParser.cs:120-123: a non-Unknown resolution upgrades the
    // resolution-detection source to Name, regardless of whether any source
    // branch ultimately consumes the resolution value.
    let resolution_detection_source = if resolution != Resolution::Unknown {
        QualityDetectionSource::Name
    } else {
        QualityDetectionSource::Unknown
    };

    // Helper to materialise a final QualityModel with the per-cascade-arm
    // detection-source flips applied. Source detection source is set to Name
    // whenever this helper fires (every caller is inside a sourceMatch arm).
    let mk = |quality: Quality, resolution_source: QualityDetectionSource| QualityModel {
        quality,
        revision,
        source_detection_source: QualityDetectionSource::Name,
        resolution_detection_source: resolution_source,
        revision_detection_source,
    };

    if let Some(sm) = source_match {
        match sm.group {
            // C# QualityParser.cs:129-173. Bluray.
            SourceGroup::Bluray => {
                if codec_xvid || codec_divx {
                    // Line 131-135: codec downgrade.
                    return mk(Quality::Bluray480p, resolution_detection_source);
                }
                match resolution {
                    // Line 137-142: 2160p (with remux variant).
                    Resolution::R2160p => {
                        let q = if remux_match {
                            Quality::Bluray2160pRemux
                        } else {
                            Quality::Bluray2160p
                        };
                        return mk(q, resolution_detection_source);
                    }
                    // Line 144-148: 1080p (with remux variant).
                    Resolution::R1080p => {
                        let q = if remux_match {
                            Quality::Bluray1080pRemux
                        } else {
                            Quality::Bluray1080p
                        };
                        return mk(q, resolution_detection_source);
                    }
                    // Line 150-154: 576p.
                    Resolution::R576p => {
                        return mk(Quality::Bluray576p, resolution_detection_source);
                    }
                    // Line 156-161: 360p / 480p / 540p collapse to 480p.
                    Resolution::R360p | Resolution::R480p | Resolution::R540p => {
                        return mk(Quality::Bluray480p, resolution_detection_source);
                    }
                    // Line 165 explicit comment: "Treat a remux without a
                    // source as 1080p, not 720p. 720p remux should fallback
                    // as 720p BluRay." So the R720p arm ignores `remux_match`
                    // and routes to Bluray720p. The R720p arm in C# is the
                    // implicit fall-through after the resolution checks fail
                    // to match anything except R720p; we make that explicit.
                    Resolution::R720p => {
                        return mk(Quality::Bluray720p, resolution_detection_source);
                    }
                    // Line 165-169 + 171-172: Unknown resolution falls
                    // through to the remux-fallback (1080pRemux) when remux
                    // fired, otherwise the C# implicit default of Bluray720p.
                    Resolution::Unknown => {
                        if remux_match {
                            return mk(Quality::Bluray1080pRemux, resolution_detection_source);
                        }
                        return mk(Quality::Bluray720p, resolution_detection_source);
                    }
                }
            }

            // C# QualityParser.cs:175-203. Webdl.
            SourceGroup::Webdl => match resolution {
                Resolution::R2160p => return mk(Quality::Webdl2160p, resolution_detection_source),
                Resolution::R1080p => return mk(Quality::Webdl1080p, resolution_detection_source),
                Resolution::R720p => return mk(Quality::Webdl720p, resolution_detection_source),
                _ => {
                    // Line 195-199: raw-name `[WEBDL]` substring -> 720p.
                    if raw.contains("[WEBDL]") {
                        return mk(Quality::Webdl720p, resolution_detection_source);
                    }
                    return mk(Quality::Webdl480p, resolution_detection_source);
                }
            },

            // C# QualityParser.cs:205-227. Webrip.
            SourceGroup::Webrip => match resolution {
                Resolution::R2160p => return mk(Quality::Webrip2160p, resolution_detection_source),
                Resolution::R1080p => return mk(Quality::Webrip1080p, resolution_detection_source),
                Resolution::R720p => return mk(Quality::Webrip720p, resolution_detection_source),
                _ => return mk(Quality::Webrip480p, resolution_detection_source),
            },

            // C# QualityParser.cs:229-263. Hdtv.
            SourceGroup::Hdtv => {
                // Line 231-234: MPEG2 short-circuit. C#'s MPEG2_REGEX is
                // case-sensitive (verified at T4) and runs against
                // normalizedName.
                if MPEG2_REGEX.is_match(normalized) {
                    return mk(Quality::RawHd, resolution_detection_source);
                }
                match resolution {
                    Resolution::R2160p => {
                        return mk(Quality::Hdtv2160p, resolution_detection_source);
                    }
                    Resolution::R1080p => {
                        return mk(Quality::Hdtv1080p, resolution_detection_source);
                    }
                    Resolution::R720p => return mk(Quality::Hdtv720p, resolution_detection_source),
                    _ => {
                        // Line 255-259: raw-name `[HDTV]` substring -> 720p.
                        if raw.contains("[HDTV]") {
                            return mk(Quality::Hdtv720p, resolution_detection_source);
                        }
                        return mk(Quality::Sdtv, resolution_detection_source);
                    }
                }
            }

            // C# QualityParser.cs:265-283. BDRip / BRRip.
            SourceGroup::Bdrip | SourceGroup::Brrip => match resolution {
                Resolution::R720p => return mk(Quality::Bluray720p, resolution_detection_source),
                Resolution::R1080p => return mk(Quality::Bluray1080p, resolution_detection_source),
                Resolution::R2160p => return mk(Quality::Bluray2160p, resolution_detection_source),
                _ => return mk(Quality::Bluray480p, resolution_detection_source),
            },

            // C# QualityParser.cs:285-289. DVD source.
            SourceGroup::Dvd => return mk(Quality::Dvd, resolution_detection_source),

            // C# QualityParser.cs:291-317. PDTV / SDTV / DSR / TVRip cluster.
            SourceGroup::Pdtv | SourceGroup::Sdtv | SourceGroup::Dsr | SourceGroup::Tvrip => {
                // Line 296-300: 1080p (regex hit OR substring fallback).
                if resolution == Resolution::R1080p
                    || contains_ignore_ascii_case(normalized, "1080p")
                {
                    return mk(Quality::Hdtv1080p, resolution_detection_source);
                }
                // Line 302-306: 720p (regex hit OR substring fallback).
                if resolution == Resolution::R720p || contains_ignore_ascii_case(normalized, "720p")
                {
                    return mk(Quality::Hdtv720p, resolution_detection_source);
                }
                // Line 308-313: HighDefPdtv (hr-ws). C# explicitly sets
                // ResolutionDetectionSource = Name on this branch even though
                // the resolution regex did NOT fire.
                if HIGH_DEF_PDTV_REGEX.is_match(normalized) {
                    return mk(Quality::Hdtv720p, QualityDetectionSource::Name);
                }
                return mk(Quality::Sdtv, resolution_detection_source);
            }
        }
    }

    // ---------------------------------------------------------------------
    // T8 fallthrough cascade (C# QualityParser.cs:320-595).
    // ---------------------------------------------------------------------
    //
    // From here down, source_match is None (every source-arm above returned).
    // The C# control flow runs the following blocks in order; each returns
    // on a hit. We reuse the modifier+resolution_detection_source values
    // gathered above.

    // Builder for branches that flip source_detection_source to Name (anime,
    // pixel-tag, bare-bluray, OtherSourceMatch). Identical to the T7 `mk`
    // closure; defined here to avoid borrowing the T7 closure across the
    // T8 boundary.
    let mk_named = |quality: Quality, resolution_source: QualityDetectionSource| QualityModel {
        quality,
        revision,
        source_detection_source: QualityDetectionSource::Name,
        resolution_detection_source: resolution_source,
        revision_detection_source,
    };

    // C# QualityParser.cs:320-347: sourceless remux. Explicit C# behaviour
    // (line 322): `result.SourceDetectionSource = QualityDetectionSource.Unknown;`
    // even though we matched a remux signal. Resolutions outside
    // {480p, 720p, 1080p, 2160p} (e.g. 360p, 540p, 576p) fall through to the
    // anime / resolution-only branches.
    if source_match.is_none() && remux_match && resolution != Resolution::Unknown {
        let q = match resolution {
            Resolution::R480p => Some(Quality::Bluray480p),
            Resolution::R720p => Some(Quality::Bluray720p),
            Resolution::R2160p => Some(Quality::Bluray2160pRemux),
            Resolution::R1080p => Some(Quality::Bluray1080pRemux),
            _ => None,
        };
        if let Some(quality) = q {
            return QualityModel {
                quality,
                revision,
                // C# line 322 hard-codes Unknown here.
                source_detection_source: QualityDetectionSource::Unknown,
                resolution_detection_source,
                revision_detection_source,
            };
        }
    }

    // C# QualityParser.cs:349-390: anime-bluray. Matches before the
    // resolution-only fallback because C#'s control flow checks anime
    // detection first (at the same depth as sourceless-remux). NB: the
    // 480p substring path collapses to `Quality::Dvd`, NOT a Bluray480p
    // variant, intentionally per C# line 359.
    if matches_anime_bluray(normalized) {
        // Anime-bluray treats the substring "480p" as equivalent to a 480p
        // resolution token even when the resolution regex didn't fire.
        // The substring path explicitly flips ResolutionDetectionSource to
        // Name (C# lines 358 / 366 / 374).
        let resolution_source_anime = QualityDetectionSource::Name;

        if matches!(
            resolution,
            Resolution::R360p | Resolution::R480p | Resolution::R540p | Resolution::R576p
        ) || contains_ignore_ascii_case(normalized, "480p")
        {
            return mk_named(Quality::Dvd, resolution_source_anime);
        }

        if resolution == Resolution::R1080p || contains_ignore_ascii_case(normalized, "1080p") {
            let q = if remux_match {
                Quality::Bluray1080pRemux
            } else {
                Quality::Bluray1080p
            };
            return mk_named(q, resolution_source_anime);
        }

        if resolution == Resolution::R2160p || contains_ignore_ascii_case(normalized, "2160p") {
            let q = if remux_match {
                Quality::Bluray2160pRemux
            } else {
                Quality::Bluray2160p
            };
            return mk_named(q, resolution_source_anime);
        }

        // C# line 382-386: remux without a 720p resolution (incl. Unknown)
        // collapses to 1080pRemux. R720p with remux falls through to the
        // 720p default below.
        if remux_match && resolution != Resolution::R720p {
            return mk_named(Quality::Bluray1080pRemux, resolution_detection_source);
        }

        // C# line 388: anime-bluray default is 720p. Resolution detection
        // source carries through whatever the regex hit: if R720p fired the
        // regex, it's Name; else Unknown.
        return mk_named(Quality::Bluray720p, resolution_detection_source);
    }

    // C# QualityParser.cs:392-424: anime-webdl. Substring "480p" / "1080p" /
    // "2160p" promotes the resolution-detection source to Name even when the
    // regex itself didn't fire (C# lines 400 / 408 / 416).
    if ANIME_WEBDL_REGEX.is_match(normalized) {
        let resolution_source_anime = QualityDetectionSource::Name;

        if matches!(
            resolution,
            Resolution::R360p | Resolution::R480p | Resolution::R540p | Resolution::R576p
        ) || contains_ignore_ascii_case(normalized, "480p")
        {
            return mk_named(Quality::Webdl480p, resolution_source_anime);
        }

        if resolution == Resolution::R1080p || contains_ignore_ascii_case(normalized, "1080p") {
            return mk_named(Quality::Webdl1080p, resolution_source_anime);
        }

        if resolution == Resolution::R2160p || contains_ignore_ascii_case(normalized, "2160p") {
            return mk_named(Quality::Webdl2160p, resolution_source_anime);
        }

        // C# line 422: anime-webdl default is 720p.
        return mk_named(Quality::Webdl720p, resolution_detection_source);
    }

    // C# QualityParser.cs:426-497: resolution-only fallback. Derives a
    // QualitySource from EITHER remuxMatch (BlurayRaw) OR the file extension
    // via MediaFileExtensions, then uses find_by_source_and_resolution. When
    // the derived source is Unknown, falls back to the Television-class
    // default for each resolution.
    if resolution != Resolution::Unknown {
        // C# line 428 + 432-451. `source` defaults to Unknown; `remuxMatch`
        // sets it to BlurayRaw (and flips SourceDetectionSource to Name);
        // otherwise the extension lookup may set it via the path's last
        // dotted token.
        let mut derived_source = QualitySource::Unknown;
        let mut source_detection = QualityDetectionSource::Unknown;

        if remux_match {
            derived_source = QualitySource::BlurayRaw;
            source_detection = QualityDetectionSource::Name;
        } else {
            // C# line 437-450 calls Sonarr's GetPathExtension
            // (LastIndexOf('.')), distinct from Path.GetExtension. The C#
            // version wraps the call in try/catch over ArgumentException,
            // but our Rust port's get_path_extension is total (no exceptions);
            // we read the extension verbatim and rely on
            // quality_for_extension to return Unknown for empty / unrecognised
            // inputs.
            //
            // C# uses `name` (raw) here, NOT `normalizedName`. For path-like
            // inputs that contain underscores (e.g. extension `.dvr_ms`, but
            // the dictionary actually carries `.dvr-ms`), the `_ -> ` `
            // normalisation could turn extensions into multi-token strings.
            // We mirror C# faithfully and read from `raw`.
            let ext = get_path_extension(raw);
            let from_ext = quality_for_extension(ext);
            if from_ext != Quality::Unknown {
                derived_source = quality_source(from_ext);
                source_detection = QualityDetectionSource::Extension;
            }
        }

        // Build the result with the resolution-arm-specific source/resolution
        // detection-source flips.
        let mk_resfb = |quality: Quality| QualityModel {
            quality,
            revision,
            source_detection_source: source_detection,
            // C# lines 455 / 466 / 477 / 489: ResolutionDetectionSource
            // explicitly set to Name in every resolution-only return.
            resolution_detection_source: QualityDetectionSource::Name,
            revision_detection_source,
        };

        let q = match resolution {
            Resolution::R2160p => {
                if derived_source == QualitySource::Unknown {
                    Quality::Hdtv2160p
                } else {
                    crate::quality::finder::find_by_source_and_resolution(derived_source, 2160)
                }
            }
            Resolution::R1080p => {
                if derived_source == QualitySource::Unknown {
                    Quality::Hdtv1080p
                } else {
                    crate::quality::finder::find_by_source_and_resolution(derived_source, 1080)
                }
            }
            Resolution::R720p => {
                if derived_source == QualitySource::Unknown {
                    Quality::Hdtv720p
                } else {
                    crate::quality::finder::find_by_source_and_resolution(derived_source, 720)
                }
            }
            Resolution::R360p | Resolution::R480p | Resolution::R540p | Resolution::R576p => {
                if derived_source == QualitySource::Unknown {
                    Quality::Sdtv
                } else {
                    crate::quality::finder::find_by_source_and_resolution(derived_source, 480)
                }
            }
            // Resolution::Unknown is excluded by the outer `if`.
            Resolution::Unknown => unreachable!("resolution != Unknown gated by outer if"),
        };

        return mk_resfb(q);
    }

    // C# QualityParser.cs:499-504: x264 codec with no other signal -> SDTV.
    // The codec_caps were already gathered above. This branch does NOT flip
    // any detection source to Name; per C# line 501 only Quality is set.
    if codec_caps.as_ref().and_then(|c| c.name("x264")).is_some() {
        return QualityModel {
            quality: Quality::Sdtv,
            revision,
            source_detection_source: QualityDetectionSource::Unknown,
            resolution_detection_source,
            revision_detection_source,
        };
    }

    // C# QualityParser.cs:506-526: 848x480 pixel tag. NB: C# uses
    // case-sensitive `Contains("dvd")` here (line 510) and case-insensitive
    // `ContainsIgnoreCase("bluray")` (line 515). We mirror that asymmetry.
    if normalized.contains("848x480") {
        if normalized.contains("dvd") {
            return mk_named(Quality::Dvd, QualityDetectionSource::Name);
        }
        if contains_ignore_ascii_case(normalized, "bluray") {
            return mk_named(Quality::Bluray480p, QualityDetectionSource::Name);
        }
        // Bare 848x480 with no source marker: only the resolution detection
        // source flips to Name; the quality is SDTV. C# line 522 doesn't
        // set SourceDetectionSource on this default-arm.
        return QualityModel {
            quality: Quality::Sdtv,
            revision,
            source_detection_source: QualityDetectionSource::Unknown,
            resolution_detection_source: QualityDetectionSource::Name,
            revision_detection_source,
        };
    }

    // C# QualityParser.cs:528-543: 1280x720 pixel tag. Both C# checks are
    // case-insensitive (line 528 + 532).
    if contains_ignore_ascii_case(normalized, "1280x720") {
        if contains_ignore_ascii_case(normalized, "bluray") {
            return mk_named(Quality::Bluray720p, QualityDetectionSource::Name);
        }
        return QualityModel {
            quality: Quality::Hdtv720p,
            revision,
            source_detection_source: QualityDetectionSource::Unknown,
            resolution_detection_source: QualityDetectionSource::Name,
            revision_detection_source,
        };
    }

    // C# QualityParser.cs:545-560: 1920x1080 pixel tag. Same shape as 1280x720.
    if contains_ignore_ascii_case(normalized, "1920x1080") {
        if contains_ignore_ascii_case(normalized, "bluray") {
            return mk_named(Quality::Bluray1080p, QualityDetectionSource::Name);
        }
        return QualityModel {
            quality: Quality::Hdtv1080p,
            revision,
            source_detection_source: QualityDetectionSource::Unknown,
            resolution_detection_source: QualityDetectionSource::Name,
            revision_detection_source,
        };
    }

    // C# QualityParser.cs:562-587: bare bluray-resolution tokens. The literal
    // "bluray720p" / "bluray1080p" / "bluray2160p" without separators bypasses
    // SOURCE_REGEX (which expects word boundaries around `BluRay`).
    if contains_ignore_ascii_case(normalized, "bluray720p") {
        return mk_named(Quality::Bluray720p, QualityDetectionSource::Name);
    }
    if contains_ignore_ascii_case(normalized, "bluray1080p") {
        return mk_named(Quality::Bluray1080p, QualityDetectionSource::Name);
    }
    if contains_ignore_ascii_case(normalized, "bluray2160p") {
        return mk_named(Quality::Bluray2160p, QualityDetectionSource::Name);
    }

    // C# QualityParser.cs:589-595 + 653-672: OtherSourceMatch. HD-TV / SD-TV
    // alternative-form via OTHER_SOURCE_REGEX. Only Quality + source-detection
    // are set; resolution-detection-source carries through from above.
    if let Some(caps) = OTHER_SOURCE_REGEX.captures(normalized) {
        let q = if caps.name("sdtv").is_some() {
            Some(Quality::Sdtv)
        } else if caps.name("hdtv").is_some() {
            Some(Quality::Hdtv720p)
        } else {
            None
        };
        if let Some(quality) = q {
            return QualityModel {
                quality,
                revision,
                source_detection_source: QualityDetectionSource::Name,
                resolution_detection_source,
                revision_detection_source,
            };
        }
    }

    // Carry-out: nothing matched. Return the default with the parsed revision
    // and any resolution-detection-source flag we accumulated.
    QualityModel {
        revision,
        revision_detection_source,
        resolution_detection_source,
        ..Default::default()
    }
}

/// **Canonical entry-point** for parsing a release name into a
/// [`QualityModel`](crate::quality::QualityModel). Ported from
/// `QualityParser.cs:68-98` (`ParseQuality`). Use [`parse_quality_name`]
/// only if you need to bypass the extension lookup.
///
/// Wraps [`parse_quality_name`] with the C# extension fallback at lines
/// 81-95: when the inner cascade returns `Quality::Unknown`, look up the file
/// extension via [`quality_for_extension`] and overlay the result. The C#
/// branch sets `SourceDetectionSource` and `ResolutionDetectionSource` to
/// `Extension` BEFORE inspecting the returned Quality (lines 87-88), so even
/// a recognised-but-`Unknown` extension (e.g. `.webm`) flips both flags.
///
/// C# guards this branch with `!name.ContainsInvalidPathChars()`. The Rust
/// port mirrors that guard via [`contains_invalid_path_chars`], which is the
/// `Path::GetInvalidPathChars()` set: NUL plus the C0 control range
/// `\x00-\x1F`. Cross-platform, no Windows-only chars (matches the C#
/// behaviour where `Path.GetInvalidPathChars` excludes the per-platform
/// "additional" chars like `<>:"/\?*`).
pub fn parse_quality(name: &str) -> crate::quality::QualityModel {
    use crate::quality::{Quality, QualityDetectionSource};

    let trimmed = name.trim();
    let mut result = parse_quality_name(trimmed);

    if result.quality == Quality::Unknown && !contains_invalid_path_chars(trimmed) {
        let ext = get_path_extension(trimmed);
        // C# QualityParser.cs:87-88: detection sources are set BEFORE the
        // dictionary lookup, so even an Unknown-mapped extension (e.g.
        // `.webm`) flips both flags. Mirror that ordering.
        result.source_detection_source = QualityDetectionSource::Extension;
        result.resolution_detection_source = QualityDetectionSource::Extension;
        result.quality = quality_for_extension(ext);
    }

    result
}

/// Mirrors `string.ContainsInvalidPathChars` from
/// `NzbDrone.Common/Extensions/PathExtensions.cs:184-192`. Returns true if
/// the string contains any character that .NET's
/// `Path.GetInvalidPathChars()` lists.
///
/// On both .NET Framework and .NET Core, `Path.GetInvalidPathChars()` returns
/// `{ '\0', '\x01' .. '\x1F' }` (NUL plus the C0 control range). It does NOT
/// include the per-platform "additional" characters (`<>:"/\?*` on Windows)
/// because those are reserved for `Path.GetInvalidFileNameChars()`. Mirroring
/// the C# behaviour means we accept release names containing `:` or `/` etc.
/// even though those would be invalid in a real filesystem path.
fn contains_invalid_path_chars(text: &str) -> bool {
    text.bytes().any(|b| b == 0 || (0x01..=0x1F).contains(&b))
}

/// Modifier-parsing helper. Ported from `QualityParser.cs:675-711`.
///
/// Returns `(revision, revision_detection_source)`. The detection source is
/// `Name` if any of the four C# modifier branches fire (Version, Proper,
/// Repack, Real); otherwise `Unknown`.
///
/// Order of operations (mirrors C#):
///
/// 1. **Version regex** (line 679): on hit, set `version = N`.
/// 2. **Proper regex** (line 687): on hit, set `version = (versionMatch ? N : 1) + 1`.
///    Equivalently: if Version did not fire, version is 2; if it did, version
///    is the captured N + 1. This is **assignment**, not increment, so a
///    second Proper hit does not bump again.
/// 3. **Repack regex** (line 693): on hit, same assignment as Proper, plus
///    `is_repack = true`. If both Proper and Repack fire, the Repack branch
///    overrides the Proper version (both compute the same value, so the
///    practical effect is just the `is_repack` flag).
/// 4. **Real regex** (line 702): set `real = matches.Count` (count, not
///    flag). Uses the **raw** input `name`, not the normalised one. The
///    other three branches use `normalizedName`. This is intentional in C#
///    and we preserve it.
///
/// Plan-spec drift notes (resolved in favour of C#):
///
/// - The plan-spec drafted Proper as `version += 1` (increment). C# uses
///   assignment with a Version-aware fallback. Ported per C#.
/// - The plan-spec ordered the checks Proper -> Repack -> Version -> Real.
///   C# orders them Version -> Proper -> Repack -> Real. Ported per C#.
/// - The plan-spec modelled `Real` as `bool`. C# stores it as `int` with
///   `Matches.Count` semantics. The Rust port carries `Revision.real: u32`;
///   this helper writes the count.
fn parse_quality_modifiers(
    name: &str,
    normalized_name: &str,
) -> (
    crate::quality::Revision,
    crate::quality::QualityDetectionSource,
) {
    use crate::quality::{QualityDetectionSource, Revision};

    let mut rev = Revision::default();
    let mut detection = QualityDetectionSource::Unknown;

    // Step 1: Version regex (C# line 679, run against normalizedName).
    // Walks all 5 named groups (`version` through `version5`) per the
    // VERSION_REGEX doc-comment, picking the first that captured. The captured
    // text is a single ASCII digit, so `parse::<u32>()` cannot widen overflow.
    let version_caps = VERSION_REGEX.captures(normalized_name);
    let version_value: Option<u32> = version_caps.as_ref().and_then(|caps| {
        caps.name("version")
            .or_else(|| caps.name("version2"))
            .or_else(|| caps.name("version3"))
            .or_else(|| caps.name("version4"))
            .or_else(|| caps.name("version5"))
            .and_then(|m| m.as_str().parse().ok())
    });
    if let Some(v) = version_value {
        rev.version = v;
        detection = QualityDetectionSource::Name;
    }

    // Step 2: Proper regex (C# line 687, run against normalizedName).
    // C#: `result.Revision.Version = versionRegexResult.Success ? Convert.ToInt32(...) + 1 : 2;`
    // -- assignment, not increment. The fallback when Version did NOT fire is
    // the literal 2 (NOT the current `rev.version + 1`).
    if PROPER_REGEX.is_match(normalized_name) {
        rev.version = match version_value {
            Some(v) => v + 1,
            None => 2,
        };
        detection = QualityDetectionSource::Name;
    }

    // Step 3: Repack regex (C# line 693, run against normalizedName).
    // Same assignment semantics as Proper, plus IsRepack = true.
    if REPACK_REGEX.is_match(normalized_name) {
        rev.version = match version_value {
            Some(v) => v + 1,
            None => 2,
        };
        rev.is_repack = true;
        detection = QualityDetectionSource::Name;
    }

    // Step 4: Real regex (C# line 702, run against the RAW name -- not
    // normalizedName -- because that is what C# does. Real is case-sensitive
    // (REAL_REGEX has no `(?i)` flag). The C# code uses `Matches(name).Count`,
    // which we mirror via `find_iter().count()`.
    let real_count = REAL_REGEX.find_iter(name).count();
    if real_count > 0 {
        // C# stores the raw count; we cap at `u32::MAX` defensively because
        // `usize` is wider on 64-bit hosts. In practice the count is bounded
        // by input length, which is bounded by Sonarr's release-name limit
        // (well under 4 billion).
        rev.real = u32::try_from(real_count).unwrap_or(u32::MAX);
        detection = QualityDetectionSource::Name;
    }

    (rev, detection)
}

#[cfg(test)]
mod tests {
    use super::regexes::*;
    use super::{
        SourceGroup, detect_resolution, match_remux, match_source, match_source_last,
        matches_alternative_resolution, matches_anime_bluray, parse_quality, parse_quality_name,
    };
    use crate::quality::{Quality, QualityDetectionSource, Resolution};

    // Source-regex direct hits.

    #[test]
    fn source_regex_detects_bluray() {
        let m = SOURCE_REGEX
            .captures("Movie.2020.1080p.BluRay.x264")
            .unwrap();
        assert!(m.name("bluray").is_some());
    }

    #[test]
    fn source_regex_detects_webdl() {
        let m = SOURCE_REGEX
            .captures("Show.S01E01.WEB-DL.AAC.x264")
            .unwrap();
        assert!(m.name("webdl").is_some());
    }

    #[test]
    fn source_regex_detects_webrip() {
        let m = SOURCE_REGEX.captures("Show.S01E01.WEBRip.x264").unwrap();
        assert!(m.name("webrip").is_some());
    }

    #[test]
    fn source_regex_detects_hdtv() {
        let m = SOURCE_REGEX.captures("Show.S01E01.HDTV.x264").unwrap();
        assert!(m.name("hdtv").is_some());
    }

    #[test]
    fn source_regex_detects_dvd() {
        let m = SOURCE_REGEX.captures("Movie.2010.DVDRip.XviD").unwrap();
        assert!(m.name("dvd").is_some());
    }

    // Source helper: lookaround workarounds.

    #[test]
    fn match_source_rejects_bare_bd_at_end_of_string() {
        // C# `BD(?!$)`. Bare `BD` at end of input must NOT match the bluray branch.
        // The release name "Show.BD" should fall through to other branches or yield None.
        // We craft an input where the only `BD`-shaped token is at the very end.
        let result = match_source("Show.S01E01.BD");
        // Either no match or a non-bluray match is acceptable; the bluray reject is the gate.
        if let Some(found) = result {
            assert_ne!(
                found.group,
                SourceGroup::Bluray,
                "bare BD at EOL should not match bluray; got matched={:?}",
                found.matched
            );
        }
    }

    #[test]
    fn match_source_accepts_bd_when_followed_by_more() {
        // `BD` mid-string is fine.
        let m = match_source("Show.BD.x264.somegroup").expect("should match bluray");
        assert_eq!(m.group, SourceGroup::Bluray);
        // Case-exact: input is uppercase BD; assert the regex returned the literal "BD"
        // rather than any normalised text. Catches accidental case-folding regressions.
        assert_eq!(m.matched, "BD");
    }

    #[test]
    fn match_source_accepts_bdmux_at_eol() {
        // `BDMux` is its own alternative and is not constrained by the BD-not-at-EOL rule.
        let m = match_source("Show.BDMux").expect("BDMux at EOL must match bluray");
        assert_eq!(m.group, SourceGroup::Bluray);
    }

    #[test]
    fn match_source_rejects_amzn_web_rip() {
        // C# `(?:AMZN|NF|DP)[. -]WEB[. -](?!Rip)`. AMZN.WEB.Rip must NOT match webdl.
        let result = match_source("Show.S01E01.AMZN.WEB.Rip.x264");
        if let Some(found) = result {
            // Should fall through to webrip, not webdl.
            assert_ne!(
                found.group,
                SourceGroup::Webdl,
                "AMZN.WEB.Rip must not be classified as webdl; got matched={:?}",
                found.matched
            );
        }
    }

    #[test]
    fn match_source_accepts_amzn_web_dl() {
        // AMZN.WEB-DL must classify as webdl. C# semantics: the leftmost-match
        // wins, so on this input the (?:AMZN|NF|DP)[. -]WEB[. -] provider branch
        // fires first (it starts at `AMZN`, earlier than where WEB-DL begins),
        // and its (?!Rip) post-filter passes because the next char after the
        // provider match is `D`, not `R`. The end result (webdl group) is what
        // callers care about; this test pins both.
        let m = match_source("Show.S01E01.AMZN.WEB-DL.x264").expect("AMZN.WEB-DL must match webdl");
        assert_eq!(m.group, SourceGroup::Webdl);
        // Pin which branch fires. If the alternation order or anchoring ever
        // shifts so that WEB[-_. ]DL claims the match instead, this catches it.
        assert_eq!(
            m.matched.to_ascii_uppercase(),
            "AMZN.WEB-",
            "expected provider_web branch (AMZN.WEB-), got `{}`",
            m.matched
        );
    }

    #[test]
    fn match_source_accepts_amzn_web_when_not_followed_by_rip() {
        // AMZN.WEB.h264 must match the (?:AMZN|NF|DP)[. -]WEB[. -] branch since
        // the trailing chars are not Rip.
        let m = match_source("Show.S01E01.AMZN.WEB.h264").expect("AMZN.WEB.h264 must match webdl");
        assert_eq!(m.group, SourceGroup::Webdl);
    }

    #[test]
    fn source_regex_uppercase_web_at_eol_matches_webdl() {
        // The C# `[. ](?-i:WEB)$` branch matches an uppercase `WEB` at end of input.
        // `(?-i:...)` is supported natively by Rust regex, so this is a verbatim port.
        let m = SOURCE_REGEX.captures("Show.S01E01.WEB").unwrap();
        assert!(
            m.name("webdl").is_some(),
            "uppercase WEB at EOL must match webdl"
        );
    }

    #[test]
    fn source_regex_lowercase_web_at_eol_does_not_match_via_eol_branch() {
        // Verifies that `(?-i:WEB)$` is in fact case-sensitive in our port.
        // `Show.S01E01.web` has no other webdl-matching token, so the only path
        // would be the EOL branch, which must reject lowercase.
        let result = SOURCE_REGEX.captures("Show.S01E01.web");
        // Either no match, or a non-webdl branch (none should hit `web` though).
        if let Some(c) = result {
            assert!(
                c.name("webdl").is_none(),
                "lowercase web at EOL must not match webdl"
            );
        }
    }

    // RawHD.

    #[test]
    fn raw_hd_regex_detects_rawhd() {
        assert!(RAW_HD_REGEX.is_match("Show.S01E01.RawHD.MPEG2"));
    }

    #[test]
    fn raw_hd_regex_detects_raw_hyphen_hd() {
        assert!(RAW_HD_REGEX.is_match("Show.S01E01.Raw-HD"));
    }

    #[test]
    fn raw_hd_regex_does_not_match_unrelated() {
        assert!(!RAW_HD_REGEX.is_match("Show.S01E01.RAWisCool"));
    }

    // MPEG2.

    #[test]
    fn mpeg2_regex_detects_mpeg2() {
        assert!(MPEG2_REGEX.is_match("Movie.MPEG2.x264"));
    }

    #[test]
    fn mpeg2_regex_detects_mpeg_dash_2() {
        assert!(MPEG2_REGEX.is_match("Movie.MPEG-2.x264"));
    }

    #[test]
    fn mpeg2_regex_is_case_sensitive() {
        // C# uses no IgnoreCase flag on this pattern, so `mpeg2` (lowercase) must NOT match.
        assert!(!MPEG2_REGEX.is_match("Movie.mpeg2.x264"));
    }

    // Remux.

    #[test]
    fn remux_regex_detects_uhd_remux() {
        assert!(REMUX_REGEX.is_match("Movie.2020.UHD.Remux.2160p"));
    }

    #[test]
    fn remux_regex_detects_bd_remux_prefix() {
        // `_Remux` form: `\d{4}p-Remux` matches via `\d{4}p-` prefix.
        assert!(REMUX_REGEX.is_match("Movie.2020.1080p-Remux"));
    }

    #[test]
    fn remux_regex_detects_remux_then_resolution() {
        // `Remux_2160p` form: matches the second alternative.
        assert!(REMUX_REGEX.is_match("Movie.2020.Remux_2160p"));
    }

    #[test]
    fn match_remux_returns_text() {
        let s = "Movie.2020.UHD.Remux.2160p";
        let got = match_remux(s).expect("must match");
        assert!(got.to_ascii_lowercase().contains("remux"));
    }

    // Anime Bluray (lookaround workaround).

    #[test]
    fn anime_bluray_regex_detects_bd_with_resolution() {
        assert!(matches_anime_bluray("[group] Show - 01 [BD1080p]"));
    }

    #[test]
    fn anime_bluray_regex_detects_bd_in_brackets() {
        // `[BD]` -> bare `bd` surrounded by `[` and `]`.
        assert!(matches_anime_bluray("[group] Show - 01 [BD]"));
    }

    #[test]
    fn anime_bluray_regex_detects_bd_with_space() {
        // `[BD 1080p]` -> bare `bd` surrounded by `[` and ` `.
        assert!(matches_anime_bluray("[group] Show - 01 [BD 1080p]"));
    }

    #[test]
    fn anime_bluray_regex_does_not_match_substring() {
        // Without surround chars, bare `bd` inside a word must not count.
        assert!(!matches_anime_bluray("Some.abdef.movie"));
    }

    #[test]
    fn anime_bluray_regex_does_not_match_bd_then_letter() {
        // `bdrip` has surround `.` left but `r` right, must not match the bare-bd branch.
        assert!(!matches_anime_bluray("Show.bdrip"));
    }

    #[test]
    fn anime_bluray_regex_rejects_bare_bd_at_sol() {
        // C#'s (?<=[-_. (\[])bd... lookbehind cannot match at start-of-input.
        assert!(!matches_anime_bluray("bd"));
        assert!(!matches_anime_bluray("bd.x264"));
    }

    #[test]
    fn anime_bluray_regex_rejects_bare_bd_at_eol() {
        // C#'s ...bd(?=[-_. )\]]) lookahead cannot match at end-of-input.
        assert!(!matches_anime_bluray("show.bd"));
    }

    #[test]
    fn anime_bluray_regex_accepts_bd1080_at_boundaries() {
        // bd720/bd1080/bd2160 are the lookaround-free branch; boundaries are fine.
        assert!(matches_anime_bluray("bd1080"));
        assert!(matches_anime_bluray("bd1080.mkv"));
    }

    // Anime WebDL.

    #[test]
    fn anime_webdl_regex_detects_web_brackets() {
        assert!(ANIME_WEBDL_REGEX.is_match("[group] Show - 01 [WEB] [1080p]"));
    }

    #[test]
    fn anime_webdl_regex_detects_paren_web_dot() {
        assert!(ANIME_WEBDL_REGEX.is_match("(WEB.1080p) Show"));
    }

    #[test]
    fn anime_webdl_regex_does_not_match_bare_web() {
        assert!(!ANIME_WEBDL_REGEX.is_match("Show.WEB.1080p"));
    }

    // Resolution.

    #[test]
    fn resolution_regex_detects_2160p() {
        let m = RESOLUTION_REGEX.captures("Movie.2160p.HDR").unwrap();
        assert!(m.name("R2160p").is_some());
    }

    #[test]
    fn resolution_regex_detects_1280x720_as_720p() {
        let m = RESOLUTION_REGEX
            .captures("[group] Show - 01 (1280x720)")
            .unwrap();
        assert!(m.name("R720p").is_some());
    }

    #[test]
    fn resolution_regex_detects_uhd_4k_form() {
        // C# 4K branch: `(?:UHD|HEVC|BD|H265)[-_. ]4k`. `UHD-4k` must hit R2160p.
        let m = RESOLUTION_REGEX.captures("Movie.2020.UHD-4k.x265").unwrap();
        assert!(m.name("R2160p").is_some());
    }

    #[test]
    fn resolution_regex_detects_4k_uhd_form() {
        // C# 4K branch: `4k[-_. ](?:UHD|HEVC|BD|H265)`. `4k-UHD` must hit R2160p.
        let m = RESOLUTION_REGEX.captures("Movie.2020.4k-UHD.x265").unwrap();
        assert!(m.name("R2160p").is_some());
    }

    #[test]
    fn resolution_regex_detects_480p() {
        let m = RESOLUTION_REGEX.captures("Show.S01E01.480p.x264").unwrap();
        assert!(m.name("R480p").is_some());
    }

    #[test]
    fn resolution_regex_detects_1080p_fhd() {
        let m = RESOLUTION_REGEX.captures("Movie.2020.FHD.x264").unwrap();
        assert!(m.name("R1080p").is_some());
    }

    #[test]
    fn resolution_regex_detects_4kto1080p_form() {
        // C# QualityParser.cs:49 - R1080p group includes `4kto1080p` for
        // downscaled-UHD releases. Regression guard against the T5-original
        // miss that dropped this token while correcting the R2160p 4K branches.
        let m = RESOLUTION_REGEX.captures("Movie.4kto1080p.x264").unwrap();
        assert!(
            m.name("R1080p").is_some(),
            "expected R1080p branch to match `4kto1080p`"
        );
    }

    // Alternative resolution (duplicate-group workaround).

    #[test]
    fn alternative_resolution_regex_matches_uhd() {
        assert!(matches_alternative_resolution("Movie.UHD.Bluray"));
    }

    #[test]
    fn alternative_resolution_regex_matches_bracket_4k() {
        assert!(matches_alternative_resolution("Movie [4K] Bluray"));
    }

    #[test]
    fn alternative_resolution_regex_does_not_match_unrelated() {
        assert!(!matches_alternative_resolution("Movie.1080p.Bluray"));
    }

    #[test]
    fn alternative_resolution_regex_named_groups_are_distinct() {
        // Direct regex assertion: C# uses the same `<R2160p>` name twice; we
        // renamed the second to `R2160p_alt` to satisfy Rust regex's no-dup
        // rule. Confirm both names exist and fire on their respective inputs.
        let uhd = ALTERNATIVE_RESOLUTION_REGEX
            .captures("Movie.UHD.x264")
            .unwrap();
        assert!(uhd.name("R2160p").is_some());
        assert!(uhd.name("R2160p_alt").is_none());

        let four_k = ALTERNATIVE_RESOLUTION_REGEX
            .captures("Movie [4K] x264")
            .unwrap();
        assert!(four_k.name("R2160p").is_none());
        assert!(four_k.name("R2160p_alt").is_some());
    }

    // Codec.

    #[test]
    fn codec_regex_detects_xvid() {
        let m = CODEC_REGEX.captures("Show.S01E01.Xvid.AC3").unwrap();
        assert!(m.name("xvid").is_some());
    }

    #[test]
    fn codec_regex_does_not_match_x_hyphen_vid() {
        // Plan-spec drafted `X-?vid`; C# QualityParser.cs:56-57 is `Xvid`
        // literal. A future relaxation back to the hyphenated form would
        // silently widen matching. Mirror of the resolution_regex_detects_4kto1080p_form
        // regression-guard pattern.
        assert!(CODEC_REGEX.captures("Movie.X-vid.AC3").is_none());
    }

    #[test]
    fn codec_regex_detects_x264() {
        let m = CODEC_REGEX.captures("Movie.1080p.x264.AC3").unwrap();
        assert!(m.name("x264").is_some());
    }

    #[test]
    fn codec_regex_detects_h264_case_insensitive() {
        let m = CODEC_REGEX.captures("Movie.1080p.H264.AC3").unwrap();
        assert!(m.name("h264").is_some());
    }

    #[test]
    fn codec_regex_detects_xvidhd() {
        let m = CODEC_REGEX.captures("Movie.XvidHD.AC3").unwrap();
        // XvidHD must hit the xvidhd group, not xvid (alternation order matters).
        assert!(m.name("xvidhd").is_some());
        assert!(m.name("xvid").is_none());
    }

    #[test]
    fn codec_regex_detects_divx() {
        let m = CODEC_REGEX.captures("Movie.divx.AC3").unwrap();
        assert!(m.name("divx").is_some());
    }

    // Other source.

    #[test]
    fn other_source_regex_detects_hd_tv() {
        let m = OTHER_SOURCE_REGEX.captures("Show.HD-TV.x264").unwrap();
        assert!(m.name("hdtv").is_some());
    }

    #[test]
    fn other_source_regex_detects_sd_tv() {
        let m = OTHER_SOURCE_REGEX.captures("Show.SD.TV.x264").unwrap();
        assert!(m.name("sdtv").is_some());
    }

    // High-def PDTV.

    #[test]
    fn high_def_pdtv_regex_detects_hr_ws() {
        assert!(HIGH_DEF_PDTV_REGEX.is_match("Show.S01E01.hr-ws.x264"));
    }

    #[test]
    fn high_def_pdtv_regex_does_not_match_unrelated() {
        assert!(!HIGH_DEF_PDTV_REGEX.is_match("Show.S01E01.hrws.x264"));
    }

    // Proper.

    #[test]
    fn proper_regex_detects_proper() {
        assert!(PROPER_REGEX.is_match("Show PROPER 720p"));
    }

    #[test]
    fn proper_regex_detects_proper_lowercase() {
        // C# uses IgnoreCase; lowercase must match too.
        assert!(PROPER_REGEX.is_match("Show.proper.720p"));
    }

    // Repack.

    #[test]
    fn repack_regex_detects_repack() {
        assert!(REPACK_REGEX.is_match("Show REPACK2 1080p"));
    }

    #[test]
    fn repack_regex_detects_rerip() {
        assert!(REPACK_REGEX.is_match("Show.RERIP.1080p"));
    }

    #[test]
    fn repack_regex_detects_bare_repack() {
        // No trailing digit is also valid: `repack\d?` makes the digit optional.
        assert!(REPACK_REGEX.is_match("Show.REPACK.1080p"));
    }

    // Version.

    #[test]
    fn version_regex_detects_v2() {
        // Rust regex does not allow duplicate names, so we renamed the C#
        // alternation branches to version/version2/version3/version4/version5.
        // For the `1080p.v2` form, the fifth branch (`version5`) fires.
        let m = VERSION_REGEX.captures("Show 1080p v2").unwrap();
        let version = m
            .name("version")
            .or_else(|| m.name("version2"))
            .or_else(|| m.name("version3"))
            .or_else(|| m.name("version4"))
            .or_else(|| m.name("version5"))
            .expect("at least one named version group must capture");
        assert_eq!(version.as_str(), "2");
    }

    #[test]
    fn version_regex_detects_bracket_v3() {
        // `[v3]` form fires the second branch (version2 in our port).
        let m = VERSION_REGEX.captures("Show [v3] 1080p").unwrap();
        assert!(m.name("version2").is_some());
        assert_eq!(m.name("version2").unwrap().as_str(), "3");
    }

    #[test]
    fn version_regex_detects_repack_with_digit() {
        // `repack2` form fires the third branch (version3 in our port).
        let m = VERSION_REGEX.captures("Show.repack2.1080p").unwrap();
        assert!(m.name("version3").is_some());
        assert_eq!(m.name("version3").unwrap().as_str(), "2");
    }

    #[test]
    fn version_regex_detects_rerip_with_digit() {
        // `rerip3` form fires the fourth branch (version4 in our port).
        let m = VERSION_REGEX.captures("Show.rerip3.1080p").unwrap();
        assert!(m.name("version4").is_some());
        assert_eq!(m.name("version4").unwrap().as_str(), "3");
    }

    #[test]
    fn version_regex_detects_digit_v_digit_form() {
        // `01-v2_` form fires the first branch (version in our port).
        // Pattern: `\d[-._ ]?v(?<version>\d)[-._ ]`.
        let m = VERSION_REGEX.captures("Show 01-v2_1080p").unwrap();
        assert!(m.name("version").is_some());
        assert_eq!(m.name("version").unwrap().as_str(), "2");
    }

    // Real (case-sensitive).

    #[test]
    fn real_regex_detects_real() {
        assert!(REAL_REGEX.is_match("Show REAL PROPER 1080p"));
    }

    #[test]
    fn real_regex_is_case_sensitive() {
        // C# `RealRegex` carries no IgnoreCase flag, so lowercase `real` must
        // NOT match. This gates the absence of the `(?i)` flag in our port.
        assert!(!REAL_REGEX.is_match("show real proper"));
        assert!(!REAL_REGEX.is_match("Show Real Proper"));
    }

    // T6 cascade entry-point + modifier parsing.
    //
    // Cross-checked against `QualityParser.cs:100-112` (ParseQualityName) and
    // `QualityParser.cs:675-711` (ParseQualityModifiers). Plan-spec versus C#
    // discrepancies are noted in `parse_quality_modifiers` itself; the tests
    // below pin C# semantics (the source of truth).

    #[test]
    fn parses_proper_increments_revision() {
        // C# (line 689): proper sets version = match? +1 : 2 (no version match
        // here, so version becomes 2).
        let m = parse_quality_name("Show S01E01 PROPER HDTV XviD");
        assert_eq!(m.revision.version, 2);
    }

    #[test]
    fn parses_repack_sets_is_repack() {
        // C# (line 696): repack sets IsRepack = true. version becomes 2 via the
        // same fallback as proper.
        let m = parse_quality_name("Show.2010.REPACK.1080p.WEB");
        assert!(m.revision.is_repack);
        assert_eq!(m.revision.version, 2);
    }

    #[test]
    fn parses_real_sets_real_flag() {
        // C# (line 706): Real = realRegexResult.Count, so for one REAL match
        // the count is 1. The PROPER on this input bumps version to 2 (the
        // REAL itself does not change version).
        let m = parse_quality_name("Show.REAL.PROPER.1080p");
        assert_eq!(m.revision.real, 1);
        assert_eq!(m.revision.version, 2);
    }

    #[test]
    fn parses_explicit_version_2() {
        // C# (line 683): VersionRegex sets version = N. The 5th VERSION_REGEX
        // branch fires for the `1080p.v2` form.
        let m = parse_quality_name("Show.S01E01.1080p.v2");
        assert_eq!(m.revision.version, 2);
    }

    #[test]
    fn raw_hd_short_circuits() {
        // C# (line 105): if RawHDRegex matches, set Quality = RAWHD and return
        // immediately. The cascade bails before considering source/resolution.
        let m = parse_quality_name("Show.S01E01.RawHD");
        assert_eq!(m.quality, Quality::RawHd);
    }

    // Extra coverage on T6's load-bearing edges.

    #[test]
    fn parse_quality_name_default_when_no_modifiers_or_rawhd() {
        // No modifiers, no RawHD: T6 returns the default QualityModel with
        // version=1 and Quality::Unknown. T7's source-to-quality cascade is
        // what flips Quality based on source/resolution; T6 must not.
        let m = parse_quality_name("Show.S01E01.MysteryFormat");
        assert_eq!(m.quality, Quality::Unknown);
        assert_eq!(m.revision.version, 1);
        assert_eq!(m.revision.real, 0);
        assert!(!m.revision.is_repack);
    }

    #[test]
    fn parse_quality_name_empty_input_returns_default() {
        // C# ParseQuality:72 short-circuits on IsNullOrWhiteSpace. The Rust
        // port handles empty input via natural cascade fallthrough (no source
        // match, no resolution, no modifiers -> default QualityModel).
        // Pins the graceful-empty behaviour against a future "validate
        // input non-empty" change that might panic.
        let m = parse_quality_name("");
        assert_eq!(m.quality, Quality::Unknown);
        assert_eq!(m.revision.version, 1);
        assert_eq!(m.revision.real, 0);
        assert!(!m.revision.is_repack);
    }

    #[test]
    fn parse_quality_name_normalizes_underscores() {
        // C# (line 102): name.Replace('_', ' '). PROPER sandwiched in
        // underscores must still classify as a proper. Our `\b(?<proper>proper)\b`
        // also matches across `_` boundaries (regex `\b` treats underscore as a
        // word char, so `_PROPER_` does NOT have a word boundary), which is
        // exactly why C# normalises first.
        let m = parse_quality_name("Show_S01E01_PROPER_HDTV");
        assert_eq!(m.revision.version, 2);
    }

    #[test]
    fn parse_quality_name_real_uses_raw_input_not_normalized() {
        // C# (line 702): RealRegex.Matches(name). The raw input is used, not
        // normalizedName. Real is case-sensitive uppercase. Underscores around
        // REAL are fine because the regex uses \b boundaries with word-char
        // semantics (`_` is a word char, so `_REAL_` has no \b, but that is
        // NOT a problem here because the literal `REAL` token is bordered by
        // other separators in real-world inputs).
        let m = parse_quality_name("Show.REAL.S01E01.1080p");
        assert_eq!(m.revision.real, 1);
    }

    #[test]
    fn parse_quality_name_real_underscore_bordered_does_not_match() {
        // C# uses RealRegex.Matches(name) on the RAW input. `_REAL_` has no \b
        // boundary on either side because `_` is a word-char in the regex
        // engine. If a future refactor accidentally switched Real to scan the
        // normalized name (` REAL `), the boundary would fire and this would
        // flip from 0 to 1. This test gates that drift; the existing
        // parse_quality_name_real_uses_raw_input_not_normalized test does NOT
        // discriminate (its input produces identical results raw and normalized).
        let m = parse_quality_name("Show_S01E01_REAL_1080p");
        assert_eq!(m.revision.real, 0);
    }

    #[test]
    fn parse_quality_name_real_lowercase_is_ignored() {
        // C# REAL_REGEX is case-sensitive (no IgnoreCase flag). lowercase
        // `real` must not bump the counter.
        let m = parse_quality_name("Show.real.S01E01.1080p");
        assert_eq!(m.revision.real, 0);
    }

    #[test]
    fn parse_quality_name_multi_real_counts() {
        // C# `Real = realRegexResult.Count`. Two REAL tokens => Real = 2.
        // Verifies the u32 vs bool decision: a `bool` would lose this signal.
        let m = parse_quality_name("Show.REAL.REAL.1080p");
        assert_eq!(m.revision.real, 2);
    }

    #[test]
    fn parse_quality_name_repack_with_digit_takes_version() {
        // C# (line 695): when version regex AND repack both match, the version
        // value is `versionRegexResult.Groups["version"].Value + 1`. For
        // `repack2`, the version regex captures "2", and the repack branch
        // sets version = 2 + 1 = 3.
        let m = parse_quality_name("Show.repack2.1080p");
        assert_eq!(m.revision.version, 3);
        assert!(m.revision.is_repack);
    }

    #[test]
    fn parse_quality_name_proper_with_digit_v2_takes_version() {
        // C# (line 689): version=2, proper bumps to 3.
        let m = parse_quality_name("Show.PROPER.1080p.v2");
        assert_eq!(m.revision.version, 3);
    }

    #[test]
    fn raw_hd_short_circuits_populates_detection_sources() {
        // C# (lines 107-109): when RawHD matches, source + resolution detection
        // sources are set to Name. Revision detection source is set if any
        // modifier fired (none here, so it stays Unknown).
        let m = parse_quality_name("Show.S01E01.RawHD");
        assert_eq!(
            m.source_detection_source,
            crate::quality::QualityDetectionSource::Name
        );
        assert_eq!(
            m.resolution_detection_source,
            crate::quality::QualityDetectionSource::Name
        );
        assert_eq!(
            m.revision_detection_source,
            crate::quality::QualityDetectionSource::Unknown
        );
    }

    #[test]
    fn raw_hd_short_circuits_with_proper_sets_revision_detection_source() {
        // C# (line 690): proper sets RevisionDetectionSource = Name. Even
        // through a RawHD short-circuit, the revision-detection source must
        // travel along because ParseQualityModifiers ran first.
        let m = parse_quality_name("Show.RawHD.PROPER");
        assert_eq!(m.quality, Quality::RawHd);
        assert_eq!(m.revision.version, 2);
        assert_eq!(
            m.revision_detection_source,
            crate::quality::QualityDetectionSource::Name
        );
    }

    // T7 detect_resolution helper.

    #[test]
    fn detect_resolution_returns_2160p_for_2160p_token() {
        assert_eq!(
            detect_resolution("Movie.2020.2160p.BluRay"),
            Resolution::R2160p
        );
    }

    #[test]
    fn detect_resolution_returns_2160p_for_uhd_token() {
        // Falls back to ALTERNATIVE_RESOLUTION_REGEX when the main
        // RESOLUTION_REGEX would not capture (no numeric resolution token).
        assert_eq!(
            detect_resolution("Movie.2020.UHD.BluRay"),
            Resolution::R2160p
        );
    }

    #[test]
    fn detect_resolution_returns_2160p_for_bracket_4k() {
        assert_eq!(
            detect_resolution("Movie.2020 [4K] BluRay"),
            Resolution::R2160p
        );
    }

    #[test]
    fn detect_resolution_returns_1080p_for_1080p_token() {
        assert_eq!(
            detect_resolution("Movie.2020.1080p.WEB-DL"),
            Resolution::R1080p
        );
    }

    #[test]
    fn detect_resolution_returns_720p_for_1280x720_token() {
        // C# RESOLUTION_REGEX folds 1280x720 into R720p.
        assert_eq!(detect_resolution("Show.S01E01.1280x720"), Resolution::R720p);
    }

    #[test]
    fn detect_resolution_returns_480p_for_480p_token() {
        assert_eq!(
            detect_resolution("Show.S01E01.480p.HDTV"),
            Resolution::R480p
        );
    }

    #[test]
    fn detect_resolution_returns_540p_for_540p_token() {
        assert_eq!(
            detect_resolution("Show.S01E01.540p.HDTV"),
            Resolution::R540p
        );
    }

    #[test]
    fn detect_resolution_returns_576p_for_576p_token() {
        assert_eq!(
            detect_resolution("Show.S01E01.576p.HDTV"),
            Resolution::R576p
        );
    }

    #[test]
    fn detect_resolution_returns_360p_for_360p_token() {
        assert_eq!(
            detect_resolution("Show.S01E01.360p.HDTV"),
            Resolution::R360p
        );
    }

    #[test]
    fn detect_resolution_returns_unknown_when_no_token() {
        assert_eq!(
            detect_resolution("Show.S01E01.HDTV.x264"),
            Resolution::Unknown
        );
    }

    // T7 match_source_last (LastOrDefault semantics).

    #[test]
    fn match_source_last_returns_last_when_two_distinct_sources() {
        // C# `sourceMatches.OfType<Match>().LastOrDefault()`: HDTV at the
        // start, BluRay at the end -> last match is BluRay.
        let m = match_source_last("Show.HDTV.Repack.1080p.BluRay.x264").expect("BluRay must match");
        assert_eq!(m.group, SourceGroup::Bluray);
    }

    #[test]
    fn match_source_last_returns_first_when_only_one_source() {
        // Single sourceMatch -> first == last; trivially exercised.
        let m = match_source_last("Movie.2020.1080p.BluRay.x264").expect("BluRay must match");
        assert_eq!(m.group, SourceGroup::Bluray);
    }

    #[test]
    fn match_source_last_skips_filtered_candidates() {
        // C# `BD(?!$)` rejects bare BD at end. If the only candidate is
        // filtered, return None.
        assert!(match_source_last("Show.S01E01.BD").is_none());
    }

    // T7 cascade: bluray arm.

    #[test]
    fn bluray_2160p() {
        // Plan-required test #1.
        assert_eq!(
            parse_quality_name("Movie.2020.2160p.BluRay.x265").quality,
            Quality::Bluray2160p
        );
    }

    #[test]
    fn bluray_1080p_remux() {
        // Plan-required test #2.
        assert_eq!(
            parse_quality_name("Movie.2020.1080p.BluRay.Remux.AVC").quality,
            Quality::Bluray1080pRemux
        );
    }

    #[test]
    fn bluray_720p() {
        // Plan-required test #3.
        assert_eq!(
            parse_quality_name("Movie.720p.BluRay.x264").quality,
            Quality::Bluray720p
        );
    }

    #[test]
    fn bluray_576p() {
        // C# QualityParser.cs:150-154 covers 576p as its own bucket.
        assert_eq!(
            parse_quality_name("Movie.576p.BluRay.x264").quality,
            Quality::Bluray576p
        );
    }

    #[test]
    fn bluray_480p_via_xvid_codec() {
        // C# QualityParser.cs:131-135: a bluray release with xvid OR divx
        // codec is downgraded to 480p regardless of resolution.
        assert_eq!(
            parse_quality_name("Movie.2020.BluRay.Xvid.AC3").quality,
            Quality::Bluray480p
        );
    }

    #[test]
    fn bluray_480p_via_divx_codec() {
        // C# QualityParser.cs:131-135: divx co-equal with xvid.
        assert_eq!(
            parse_quality_name("Movie.2020.BluRay.divx.AC3").quality,
            Quality::Bluray480p
        );
    }

    #[test]
    fn bluray_480p_via_low_resolution() {
        // C# QualityParser.cs:156-161: 360p / 480p / 540p collapse to 480p.
        assert_eq!(
            parse_quality_name("Movie.2020.480p.BluRay.x264").quality,
            Quality::Bluray480p
        );
        assert_eq!(
            parse_quality_name("Movie.2020.540p.BluRay.x264").quality,
            Quality::Bluray480p
        );
    }

    #[test]
    fn bluray_2160p_remux_via_2160p_token_and_remux() {
        // C# QualityParser.cs:139.
        assert_eq!(
            parse_quality_name("Movie.2020.2160p.BluRay.Remux.HDR.x265").quality,
            Quality::Bluray2160pRemux
        );
    }

    #[test]
    fn bluray_remux_unknown_resolution_falls_back_to_1080p_remux() {
        // C# QualityParser.cs:165-169: remux without a 720p resolution falls
        // back to 1080pRemux. Unknown resolution + remux + bluray -> 1080pRemux.
        assert_eq!(
            parse_quality_name("Movie.BluRay.Remux.x264").quality,
            Quality::Bluray1080pRemux
        );
    }

    #[test]
    fn bluray_720p_with_remux_stays_720p() {
        // C# QualityParser.cs:165 explicit comment: "720p remux should
        // fallback as 720p BluRay". Pin that the 720p arm ignores the remux
        // signal.
        assert_eq!(
            parse_quality_name("Movie.720p.BluRay.Remux.x264").quality,
            Quality::Bluray720p
        );
    }

    #[test]
    fn bluray_unknown_resolution_no_remux_falls_back_to_720p() {
        // C# QualityParser.cs:171-172: implicit default at the bottom of the
        // bluray arm is Bluray720p when no resolution token, no remux, no
        // codec downgrade hits. Pins the Resolution::Unknown + remux=false
        // -> Bluray720p path. The 720p-with-remux carve-out test
        // (bluray_720p_with_remux_stays_720p) covers the symmetric case;
        // this completes the matrix.
        assert_eq!(
            parse_quality_name("Movie.BluRay.x264").quality,
            Quality::Bluray720p
        );
    }

    // T7 cascade: webdl arm.

    #[test]
    fn webdl_1080p() {
        // Plan-required test #4.
        assert_eq!(
            parse_quality_name("Movie.2020.1080p.WEB-DL.x264").quality,
            Quality::Webdl1080p
        );
    }

    #[test]
    fn webdl_720p_itunes() {
        // Plan-required test #5. iTunesHD is a webdl-branch alternative.
        assert_eq!(
            parse_quality_name("Movie.720p.iTunesHD.AVC").quality,
            Quality::Webdl720p
        );
    }

    #[test]
    fn webdl_2160p() {
        // C# QualityParser.cs:177-180.
        assert_eq!(
            parse_quality_name("Movie.2020.2160p.WEB-DL.x265").quality,
            Quality::Webdl2160p
        );
    }

    #[test]
    fn webdl_480p_default() {
        // C# QualityParser.cs:201-202: any webdl with no R720p / R1080p /
        // R2160p resolution match falls back to 480p.
        assert_eq!(
            parse_quality_name("Movie.2020.WEB-DL.AAC.x264").quality,
            Quality::Webdl480p
        );
    }

    #[test]
    fn webdl_720p_via_bracket_marker() {
        // C# QualityParser.cs:195-199: raw-name `[WEBDL]` substring forces
        // 720p when no resolution match is present. The substring is checked
        // against the RAW input, NOT the normalised name (underscores become
        // spaces in normalised, but the literal bracket text is identical).
        assert_eq!(
            parse_quality_name("Movie.[WEBDL].WEB-DL.AC3").quality,
            Quality::Webdl720p
        );
    }

    // T7 cascade: webrip arm.

    #[test]
    fn webrip_2160p() {
        // Plan-required test #6.
        assert_eq!(
            parse_quality_name("Movie.2160p.WebRip.x265").quality,
            Quality::Webrip2160p
        );
    }

    #[test]
    fn webrip_1080p() {
        // C# QualityParser.cs:213-216.
        assert_eq!(
            parse_quality_name("Movie.2020.1080p.WEBRip.x264").quality,
            Quality::Webrip1080p
        );
    }

    #[test]
    fn webrip_720p() {
        // C# QualityParser.cs:219-222.
        assert_eq!(
            parse_quality_name("Show.S01E01.720p.WEBRip.x264").quality,
            Quality::Webrip720p
        );
    }

    #[test]
    fn webrip_480p_default() {
        // C# QualityParser.cs:225-226: webrip with no resolution match -> 480p.
        assert_eq!(
            parse_quality_name("Show.S01E01.WEBRip.x264").quality,
            Quality::Webrip480p
        );
    }

    // T7 cascade: hdtv arm.

    #[test]
    fn hdtv_720p() {
        // Plan-required test #7.
        assert_eq!(
            parse_quality_name("Show.S01E01.720p.HDTV.x264").quality,
            Quality::Hdtv720p
        );
    }

    #[test]
    fn hdtv_1080p() {
        // Plan-required test #8.
        assert_eq!(
            parse_quality_name("Show.S01E01.1080p.HDTV.x264").quality,
            Quality::Hdtv1080p
        );
    }

    #[test]
    fn hdtv_2160p() {
        // C# QualityParser.cs:237-240.
        assert_eq!(
            parse_quality_name("Show.S01E01.2160p.HDTV.x265").quality,
            Quality::Hdtv2160p
        );
    }

    #[test]
    fn hdtv_mpeg2_short_circuits_to_rawhd() {
        // C# QualityParser.cs:231-234: when the source is HDTV and the
        // normalized name contains MPEG2 (case-sensitive), the cascade
        // short-circuits to RAWHD even with a 1080p token in the input.
        assert_eq!(
            parse_quality_name("Show.S01E01.1080p.HDTV.MPEG2").quality,
            Quality::RawHd
        );
    }

    #[test]
    fn hdtv_mpeg2_lowercase_does_not_short_circuit() {
        // C#'s MPEG2_REGEX is case-sensitive (no IgnoreCase flag): a
        // lowercase `mpeg2` token must NOT trigger the short-circuit.
        // Matches the modifier behaviour pinned at T4 (mpeg2_regex_is_case_sensitive).
        assert_eq!(
            parse_quality_name("Show.S01E01.1080p.HDTV.mpeg2.x264").quality,
            Quality::Hdtv1080p
        );
    }

    #[test]
    fn hdtv_720p_via_bracket_marker() {
        // C# QualityParser.cs:255-259: raw-name `[HDTV]` substring forces
        // 720p when no resolution match is present.
        assert_eq!(
            parse_quality_name("Show.S01E01.[HDTV].x264").quality,
            Quality::Hdtv720p
        );
    }

    // T7 cascade: dvd arm.

    #[test]
    fn dvd() {
        // Plan-required test #9. DVD source always maps to DVD regardless of
        // resolution.
        assert_eq!(
            parse_quality_name("Movie.2010.DVDRip.XviD-AAC").quality,
            Quality::Dvd
        );
    }

    #[test]
    fn dvd_with_explicit_dvd_token() {
        // The bare `DVD` token also fires the dvd branch.
        assert_eq!(
            parse_quality_name("Movie.2010.DVD.XviD-AAC").quality,
            Quality::Dvd
        );
    }

    #[test]
    fn dvd_ntsc_token() {
        // C# QualityParser.cs:25 includes NTSC in the dvd alternation.
        assert_eq!(
            parse_quality_name("Movie.2010.NTSC.XviD-AAC").quality,
            Quality::Dvd
        );
    }

    // T7 cascade: bdrip / brrip (sub-bluray) arms.

    #[test]
    fn bdrip_720p_maps_to_bluray720p() {
        // C# QualityParser.cs:265-272.
        assert_eq!(
            parse_quality_name("Movie.720p.BDRip.x264").quality,
            Quality::Bluray720p
        );
    }

    #[test]
    fn bdrip_1080p_maps_to_bluray1080p() {
        assert_eq!(
            parse_quality_name("Movie.1080p.BDRip.x264").quality,
            Quality::Bluray1080p
        );
    }

    #[test]
    fn bdrip_default_maps_to_bluray480p() {
        // C# QualityParser.cs:280-281: BDRip default is 480p.
        assert_eq!(
            parse_quality_name("Movie.BDRip.x264").quality,
            Quality::Bluray480p
        );
    }

    #[test]
    fn brrip_2160p_maps_to_bluray2160p() {
        // C# QualityParser.cs:276-278.
        assert_eq!(
            parse_quality_name("Movie.2160p.BRRip.x265").quality,
            Quality::Bluray2160p
        );
    }

    // T7 cascade: pdtv / sdtv / dsr / tvrip arm.

    #[test]
    fn sdtv_default() {
        // Plan-required test #10. HDTV with no resolution token -> SDTV.
        // (The hdtv arm hits the no-resolution fallback at C# line 261.)
        assert_eq!(
            parse_quality_name("Show.S01E01.HDTV.x264").quality,
            Quality::Sdtv
        );
    }

    #[test]
    fn pdtv_no_resolution_maps_to_sdtv() {
        // C# QualityParser.cs:315-316.
        assert_eq!(
            parse_quality_name("Show.S01E01.PDTV.x264").quality,
            Quality::Sdtv
        );
    }

    #[test]
    fn pdtv_1080p_maps_to_hdtv1080p() {
        // C# QualityParser.cs:296-300.
        assert_eq!(
            parse_quality_name("Show.S01E01.1080p.PDTV.x264").quality,
            Quality::Hdtv1080p
        );
    }

    #[test]
    fn pdtv_720p_maps_to_hdtv720p() {
        // C# QualityParser.cs:302-306.
        assert_eq!(
            parse_quality_name("Show.S01E01.720p.PDTV.x264").quality,
            Quality::Hdtv720p
        );
    }

    #[test]
    fn pdtv_hr_ws_maps_to_hdtv720p() {
        // C# QualityParser.cs:308-312: HighDefPdtvRegex (`hr-ws`) on a pdtv
        // source promotes to Hdtv720p AND flips the resolution-detection
        // source to Name even though no resolution-regex group fired.
        let m = parse_quality_name("Show.S01E01.PDTV.hr-ws.x264");
        assert_eq!(m.quality, Quality::Hdtv720p);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn sdtv_branch_with_explicit_sdtv_token() {
        // The bare `SDTV` token routes into the pdtv-cluster arm.
        assert_eq!(
            parse_quality_name("Show.S01E01.SDTV.x264").quality,
            Quality::Sdtv
        );
    }

    #[test]
    fn dsr_branch_default_sdtv() {
        // C# QualityParser.cs:293-294: DSR routes through the pdtv-cluster
        // arm and falls back to SDTV without a resolution match.
        assert_eq!(
            parse_quality_name("Show.S01E01.DSR.x264").quality,
            Quality::Sdtv
        );
    }

    #[test]
    fn tvrip_branch_default_sdtv() {
        // C# QualityParser.cs:294: TVRip in the pdtv-cluster arm.
        assert_eq!(
            parse_quality_name("Show.S01E01.TVRip.x264").quality,
            Quality::Sdtv
        );
    }

    // T7 cascade: cross-arm semantics.

    #[test]
    fn cascade_uses_last_source_match() {
        // C# QualityParser.cs:115 LastOrDefault: HDTV appears first, BluRay
        // appears later -> classification is bluray, not hdtv. This is the
        // single most important cross-arm guarantee in the cascade.
        let m = parse_quality_name("Show.HDTV.Repack.1080p.BluRay.x264");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    #[test]
    fn cascade_populates_source_detection_when_source_fires() {
        // Any sourceMatch sets source_detection_source = Name (C# line 127).
        let m = parse_quality_name("Movie.1080p.BluRay.x264");
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn cascade_populates_resolution_detection_when_resolution_fires() {
        // C# QualityParser.cs:120-123: a non-Unknown resolution flips
        // resolution_detection_source to Name regardless of source-arm.
        let m = parse_quality_name("Movie.1080p.BluRay.x264");
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn cascade_leaves_resolution_detection_unknown_when_no_resolution() {
        // No resolution token -> resolution_detection_source stays Unknown
        // even though the source arm fires.
        let m = parse_quality_name("Movie.WEB-DL.x264");
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
        assert_eq!(
            m.resolution_detection_source,
            QualityDetectionSource::Unknown
        );
    }

    #[test]
    fn cascade_falls_back_to_unknown_when_no_source() {
        // A name with no source, no resolution, no anime markers, no codec, no
        // pixel tag, no bare-bluray token, and no OtherSourceMatch hit (no
        // recognised file extension either) returns Quality::Unknown.
        let m = parse_quality_name("Show.S01E01.MysteryFormat");
        assert_eq!(m.quality, Quality::Unknown);
    }

    #[test]
    fn cascade_resolution_only_1080p_maps_to_hdtv1080p() {
        // T8 resolution-only fallback. C# QualityParser.cs:464-473: with no
        // source match, `Movie.2020.1080p.x264` derives source from extension
        // (`.x264` is unknown -> QualitySource::Unknown), then routes via
        // line 468's `source == Unknown` branch to Quality::Hdtv1080p.
        let m = parse_quality_name("Movie.2020.1080p.x264");
        assert_eq!(m.quality, Quality::Hdtv1080p);
        // Resolution detection flips to Name because the resolution regex
        // fired (line 122 + line 466).
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn cascade_underscore_normalised_for_source_match() {
        // C# normalises `_` -> ` ` before sourceMatch. A release like
        // `Movie_1080p_BluRay_x264` must classify as bluray-1080p just like
        // its dotted twin.
        let m = parse_quality_name("Movie_2020_1080p_BluRay_x264");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    #[test]
    fn cascade_trims_outer_whitespace() {
        // C# QualityParser.cs:77 trims the raw input before the pipeline.
        // Leading/trailing whitespace must NOT change classification.
        let m = parse_quality_name("   Movie.2020.1080p.BluRay.x264   ");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    #[test]
    fn cascade_revision_carries_through_arm() {
        // PROPER bumps version to 2; the cascade must preserve the
        // revision through the bluray arm.
        let m = parse_quality_name("Movie.2020.1080p.BluRay.PROPER.x264");
        assert_eq!(m.quality, Quality::Bluray1080p);
        assert_eq!(m.revision.version, 2);
        assert_eq!(m.revision_detection_source, QualityDetectionSource::Name);
    }

    // T8 cascade: sourceless-remux (C# QualityParser.cs:320-347).

    #[test]
    fn sourceless_remux_2160p_maps_to_bluray2160p_remux() {
        // C# QualityParser.cs:336-340: REMUX + 2160p without a source token
        // routes through the sourceless-remux block to Bluray2160pRemux.
        let m = parse_quality_name("Movie.2020.2160p.Remux.HDR.x265");
        assert_eq!(m.quality, Quality::Bluray2160pRemux);
        // Line 322: SourceDetectionSource is explicitly set to Unknown for
        // sourceless remux even though we matched something.
        assert_eq!(m.source_detection_source, QualityDetectionSource::Unknown);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn sourceless_remux_1080p_maps_to_bluray1080p_remux() {
        // C# QualityParser.cs:342-346.
        let m = parse_quality_name("Movie.2020.1080p.Remux.AVC.DTS-HD");
        assert_eq!(m.quality, Quality::Bluray1080pRemux);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Unknown);
    }

    #[test]
    fn sourceless_remux_720p_maps_to_bluray720p() {
        // C# QualityParser.cs:330-334. The 720p remux without source is
        // explicitly Bluray720p, NOT Bluray720pRemux (which doesn't exist).
        let m = parse_quality_name("Movie.2020.720p.Remux.AVC");
        assert_eq!(m.quality, Quality::Bluray720p);
    }

    #[test]
    fn sourceless_remux_480p_maps_to_bluray480p() {
        // C# QualityParser.cs:324-328.
        let m = parse_quality_name("Movie.2020.480p.Remux.x264");
        assert_eq!(m.quality, Quality::Bluray480p);
    }

    // T8 cascade: anime-bluray (C# QualityParser.cs:349-390).

    #[test]
    fn anime_bluray_720p() {
        // Plan-required test #1. C# QualityParser.cs:388: anime-bluray with
        // unknown resolution falls through to default Bluray720p.
        //
        // NB: token form `[BD720p]` (no space) matches ANIME_BLURAY_REGEX's
        // `bd720` branch but NOT SOURCE_REGEX's bluray group (which requires
        // a word-boundary or space/period after `BD`). A name with `[BD 720p]`
        // (with space) would short-circuit through the T7 bluray arm instead.
        let m = parse_quality_name("[group] Show - 01 [BD720p]");
        assert_eq!(m.quality, Quality::Bluray720p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn anime_bluray_1080p() {
        // C# QualityParser.cs:364-369. Token form `[BD1080p]` matches
        // ANIME_BLURAY_REGEX's `bd1080` branch.
        let m = parse_quality_name("[group] Show - 01 [BD1080p]");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    #[test]
    fn anime_bluray_2160p() {
        // C# QualityParser.cs:372-377. Token form `[BD2160p]`.
        let m = parse_quality_name("[group] Show - 01 [BD2160p]");
        assert_eq!(m.quality, Quality::Bluray2160p);
    }

    #[test]
    fn anime_bluray_480p_maps_to_dvd() {
        // C# QualityParser.cs:354-362: anime-bluray at 360p / 480p / 540p /
        // 576p (or substring "480p") is intentionally collapsed to Quality::Dvd.
        //
        // Constructing a name that triggers this branch is delicate. Both
        // `bd720`/`bd1080`/`bd2160` literal forms AND bare `bd` with separator
        // surround can match ANIME_BLURAY_REGEX, but bare-bd with separator
        // surround ALSO matches SOURCE_REGEX's bluray group (because
        // separator chars like `[` `]` `(` `)` `-` `.` ` ` give a `\b` or
        // `[ .]` after `bd`). The only way to fire anime-bluray without
        // SOURCE_REGEX hijacking is via a `bd<digits>` literal (e.g. `bd720`)
        // because no `\b|$|[ .]` follows `bd` in that case (digits are word
        // chars).
        //
        // So we use `bd720` to fire ANIME_BLURAY_REGEX, plus a separate
        // `480p` token to drive the 480p anime-bluray sub-branch. The 720p
        // in `bd720` does NOT register as a resolution because RESOLUTION_REGEX
        // expects `\b720p\b` (and the regex needs `bd` to be separated from
        // `720` by a word boundary, which it isn't).
        let m = parse_quality_name("Show.480p.bd720.AC3");
        assert_eq!(m.quality, Quality::Dvd);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn anime_bluray_remux_no_resolution_falls_back_to_1080p_remux() {
        // C# QualityParser.cs:382-386: anime-bluray + remux + resolution !=
        // R720p (incl. Unknown) -> Bluray1080pRemux. Use the surround-bd
        // form to match anime-bluray without firing SOURCE_REGEX's bluray
        // group.
        let m = parse_quality_name("[group] Show.(bd).Remux");
        assert_eq!(m.quality, Quality::Bluray1080pRemux);
    }

    #[test]
    fn anime_bluray_1080p_remux_combo() {
        // C# QualityParser.cs:367 with remux: Bluray1080pRemux. Use the
        // surround-bd form + a 1080p resolution token.
        let m = parse_quality_name("[group] Show.1080p.(bd).Remux");
        assert_eq!(m.quality, Quality::Bluray1080pRemux);
    }

    #[test]
    fn anime_bluray_unknown_resolution_no_remux_defaults_720p() {
        // C# QualityParser.cs:388: anime-bluray with no resolution and no
        // remux defaults to Bluray720p. Surround-bd form.
        let m = parse_quality_name("[group] Show.(bd).x264");
        assert_eq!(m.quality, Quality::Bluray720p);
    }

    // T8 cascade: anime-webdl (C# QualityParser.cs:392-424).

    #[test]
    fn anime_webdl_1080p() {
        // Plan-required test #2. C# QualityParser.cs:406-411.
        let m = parse_quality_name("[group] Show - 01 [WEB][1080p]");
        assert_eq!(m.quality, Quality::Webdl1080p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn anime_webdl_2160p() {
        // C# QualityParser.cs:414-420.
        let m = parse_quality_name("[group] Show - 01 [WEB][2160p]");
        assert_eq!(m.quality, Quality::Webdl2160p);
    }

    #[test]
    fn anime_webdl_480p() {
        // C# QualityParser.cs:396-404: 480p / 540p / 576p / substring "480p"
        // -> Webdl480p.
        let m = parse_quality_name("[group] Show - 01 [WEB][480p]");
        assert_eq!(m.quality, Quality::Webdl480p);
    }

    #[test]
    fn anime_webdl_unknown_resolution_defaults_720p() {
        // C# QualityParser.cs:422: anime-webdl with no resolution defaults
        // to Webdl720p.
        let m = parse_quality_name("[group] Show - 01 (WEB.)");
        assert_eq!(m.quality, Quality::Webdl720p);
    }

    // T8 cascade: resolution-only fallback (C# QualityParser.cs:426-497).

    #[test]
    fn resolution_only_2160p_maps_to_hdtv2160p() {
        // C# QualityParser.cs:453-461. No source, 2160p resolution, no remux,
        // unknown extension -> Hdtv2160p.
        let m = parse_quality_name("Movie.2020.2160p.x265");
        assert_eq!(m.quality, Quality::Hdtv2160p);
    }

    #[test]
    fn resolution_only_720p_maps_to_hdtv720p() {
        // C# QualityParser.cs:475-484.
        let m = parse_quality_name("Movie.2020.720p.x264");
        assert_eq!(m.quality, Quality::Hdtv720p);
    }

    #[test]
    fn resolution_only_480p_maps_to_sdtv() {
        // C# QualityParser.cs:486-496. 360 / 480 / 540 / 576 -> SDTV when
        // source is Unknown.
        let m = parse_quality_name("Movie.2020.480p.x264");
        assert_eq!(m.quality, Quality::Sdtv);
    }

    #[test]
    fn resolution_only_with_mkv_extension_promotes_via_television_source() {
        // C# QualityParser.cs:437-451: extension `.mkv` resolves to Quality
        // HDTV720p (Television source). resolution-only at 1080p with
        // Television source returns find_by_source_and_resolution(Television,
        // 1080) = Quality::Hdtv1080p. The detection-source flag is Extension
        // for the source, Name for the resolution.
        let m = parse_quality_name("Movie.2020.1080p.x264.mkv");
        assert_eq!(m.quality, Quality::Hdtv1080p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn resolution_only_with_iso_extension_promotes_to_dvd_at_480p() {
        // `.iso` -> Quality::Dvd (source = Dvd). At 480p, exact match in
        // ALL[] yields Dvd directly.
        let m = parse_quality_name("Movie.2020.480p.x264.iso");
        assert_eq!(m.quality, Quality::Dvd);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
    }

    // T8 cascade: x264-SDTV fallback (C# QualityParser.cs:499-504).

    #[test]
    fn x264_codec_alone_maps_to_sdtv() {
        // C# QualityParser.cs:499-503: x264 codec with no source, no
        // resolution, no anime, no remux -> SDTV.
        let m = parse_quality_name("Movie.x264.AC3");
        assert_eq!(m.quality, Quality::Sdtv);
    }

    // T8 cascade: pixel-tag fallbacks (C# QualityParser.cs:506-560).
    //
    // RESOLUTION_REGEX already matches 848x480 / 1280x720 / 1920x1080 with
    // word boundaries, so these pixel-tag blocks only fire when the regex
    // boundary check fails. To exercise them, we glue the pixel tag against
    // surrounding text WITHOUT word boundaries.

    #[test]
    fn pixel_tag_848x480_with_dvd_token_no_word_boundary() {
        // C# QualityParser.cs:506-513: literal "848x480" + "dvd" -> DVD,
        // case-sensitive on "dvd" per C# `Contains("dvd")`.
        let m = parse_quality_name("Movie848x480dvd");
        assert_eq!(m.quality, Quality::Dvd);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn pixel_tag_848x480_with_bluray_token_no_word_boundary() {
        // C# QualityParser.cs:515-519: literal "848x480" + "bluray"
        // (case-insensitive) -> Bluray480p.
        let m = parse_quality_name("Movie848x480bluray");
        assert_eq!(m.quality, Quality::Bluray480p);
    }

    #[test]
    fn pixel_tag_848x480_default_sdtv() {
        // C# QualityParser.cs:520-523: bare "848x480" without dvd/bluray
        // marker -> SDTV.
        let m = parse_quality_name("Movie848x480extra");
        assert_eq!(m.quality, Quality::Sdtv);
    }

    #[test]
    fn pixel_tag_1280x720_default_hdtv720p() {
        // C# QualityParser.cs:528-543: bare "1280x720" without bluray ->
        // Hdtv720p.
        let m = parse_quality_name("Movie1280x720extra");
        assert_eq!(m.quality, Quality::Hdtv720p);
    }

    #[test]
    fn pixel_tag_1280x720_with_bluray_token() {
        // C# QualityParser.cs:532-536.
        let m = parse_quality_name("Movie1280x720bluray");
        assert_eq!(m.quality, Quality::Bluray720p);
    }

    #[test]
    fn pixel_tag_1920x1080_default_hdtv1080p() {
        // C# QualityParser.cs:545-560.
        let m = parse_quality_name("Movie1920x1080extra");
        assert_eq!(m.quality, Quality::Hdtv1080p);
    }

    #[test]
    fn pixel_tag_1920x1080_with_bluray_token() {
        // C# QualityParser.cs:549-553.
        let m = parse_quality_name("Movie1920x1080bluray");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    // T8 cascade: bare bluray720p/1080p/2160p tokens (C# QualityParser.cs:562-587).

    #[test]
    fn bare_bluray720p_token() {
        // C# QualityParser.cs:562-569. The literal "bluray720p" without
        // separators bypasses SOURCE_REGEX (which requires `\b|$|[ .]` after
        // `BluRay`) and RESOLUTION_REGEX (which requires `\b...720p\b`).
        // Also avoid any x264/h264 codec token: C# line 499 short-circuits
        // x264 to SDTV BEFORE this branch (`bluray720p` runs at line 562).
        let m = parse_quality_name("Movie.bluray720p.AC3");
        assert_eq!(m.quality, Quality::Bluray720p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
        assert_eq!(m.resolution_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn bare_bluray1080p_token() {
        // C# QualityParser.cs:571-578. Same x264-gating note as the 720p test.
        let m = parse_quality_name("Movie.bluray1080p.AC3");
        assert_eq!(m.quality, Quality::Bluray1080p);
    }

    #[test]
    fn bare_bluray2160p_token() {
        // C# QualityParser.cs:580-587. Same x264-gating note.
        let m = parse_quality_name("Movie.bluray2160p.AC3");
        assert_eq!(m.quality, Quality::Bluray2160p);
    }

    // T8 cascade: OtherSourceMatch (C# QualityParser.cs:589-595 + 653-672).

    #[test]
    fn other_source_hd_tv_maps_to_hdtv720p() {
        // C# QualityParser.cs:589-594 + 666-670. OTHER_SOURCE_REGEX matches
        // "HD TV" / "HD-TV" / "HD_TV" / "HD.TV" -> Hdtv720p when nothing else
        // matched. Avoid x264 codec because C# line 499 short-circuits to
        // SDTV BEFORE the OtherSourceMatch path.
        let m = parse_quality_name("Show.HD-TV.AC3.foo");
        assert_eq!(m.quality, Quality::Hdtv720p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
    }

    #[test]
    fn other_source_sd_tv_maps_to_sdtv() {
        // C# QualityParser.cs:589-594 + 661-664. Same x264-gating note.
        let m = parse_quality_name("Show.SD-TV.AC3.foo");
        assert_eq!(m.quality, Quality::Sdtv);
    }

    // T8: extension fallback (C# QualityParser.cs:81-95).

    #[test]
    fn extension_fallback_mkv_to_hdtv720p() {
        // C# QualityParser.cs:81-95: when ParseQualityName returns Unknown,
        // the outer ParseQuality wrapper looks up the file extension. `.mkv`
        // -> HDTV720p in MediaFileExtensions.
        let m = parse_quality("Show.S01E01.mkv");
        assert_eq!(m.quality, Quality::Hdtv720p);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
        assert_eq!(
            m.resolution_detection_source,
            QualityDetectionSource::Extension
        );
    }

    #[test]
    fn extension_fallback_mp4_to_sdtv() {
        // `.mp4` is mapped to Quality::SDTV in MediaFileExtensions.
        let m = parse_quality("Show.S01E01.mp4");
        assert_eq!(m.quality, Quality::Sdtv);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
    }

    #[test]
    fn extension_fallback_iso_to_dvd() {
        // `.iso` is mapped to Quality::DVD in MediaFileExtensions.
        let m = parse_quality("Show.S01E01.iso");
        assert_eq!(m.quality, Quality::Dvd);
    }

    #[test]
    fn extension_fallback_m2ts_to_bluray720p() {
        // `.m2ts` is mapped to Quality::Bluray720p in MediaFileExtensions.
        let m = parse_quality("Show.S01E01.m2ts");
        assert_eq!(m.quality, Quality::Bluray720p);
    }

    #[test]
    fn extension_fallback_webm_stays_unknown() {
        // C# MediaFileExtensions.cs:16: `.webm` -> Quality::Unknown. The
        // dictionary contains the key but maps to Unknown. SourceDetectionSource
        // and ResolutionDetectionSource are still flipped to Extension because
        // the C# branch sets them BEFORE inspecting the returned Quality.
        let m = parse_quality("Show.S01E01.webm");
        assert_eq!(m.quality, Quality::Unknown);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
    }

    #[test]
    fn extension_fallback_unknown_extension_stays_unknown() {
        // C# MediaFileExtensions.cs:76-83: an extension not in the dictionary
        // returns Quality::Unknown but the source/resolution detection
        // sources are still flipped to Extension (line 87-88 set them before
        // `GetQualityForExtension` returns Unknown). Verified against C#.
        let m = parse_quality("Show.S01E01.xyz");
        assert_eq!(m.quality, Quality::Unknown);
        assert_eq!(m.source_detection_source, QualityDetectionSource::Extension);
    }

    #[test]
    fn extension_fallback_does_not_overwrite_resolved_quality() {
        // The extension fallback only fires when ParseQualityName returned
        // Quality::Unknown. A name that already classifies (e.g. has BluRay)
        // must NOT have its quality overwritten by the extension table.
        let m = parse_quality("Movie.2020.1080p.BluRay.x264.mp4");
        assert_eq!(m.quality, Quality::Bluray1080p);
        // Source detection comes from the BluRay regex hit, not the extension.
        assert_eq!(m.source_detection_source, QualityDetectionSource::Name);
    }
}