oxdock-parser 0.28.0-alpha

use crate::ast::{Arg, Expr, StepKind};
use crate::error::{ParseError, SpanContext};
use anyhow::{Result, anyhow, bail};

/// Metadata for a single command argument.
pub struct ArgSpec {
    pub name: &'static str,
    pub arg_type: ArgType,
    pub description: &'static str,
    pub io: IoDirection,
    pub index: usize,
    pub required: bool,
    pub fallback_stream: Option<Stream>,
}

/// Closed vocabulary for argument value types: every variant names a
/// type explicitly present in the app, so the reference table never
/// lists a type that does not exist. Shapes (`$var` targets, `KEY=value`
/// pairs) are not types: the central validator only checks value types
/// and arity, while each command's `lower` enforces its own shapes with
/// command-specific errors.
/// [`ArgType::Any`] is the single exception: it renders as `<any>`,
/// visibly a placeholder rather than a type name.
/// [`ArgType::OneOf`] renders its inline options, likewise self-describing.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ArgType {
    String,
    Path,
    Int,
    Duration,
    /// A `$variable` that must hold a LIST at runtime. Non-variable
    /// expressions fail at lower time; renders linked as `LIST`.
    List,
    /// Any evaluated value (plus stream markers like `stdout` where the
    /// command accepts them). Renders unlinked as `<any>`, visibly a
    /// placeholder rather than a type name.
    Any,
    /// Inline alternation for one-off enums (e.g. `SNAPSHOT|LOCAL`).
    /// Self-describing, so it renders unlinked.
    OneOf(&'static [&'static str]),
    /// Trailing variadic repetition (e.g. `RUN`'s `string...`).
    Rest(&'static ArgType),
}

impl ArgType {
    /// Table-cell label for the argument table's Type column.
    /// Canonical value types use their descriptor names; `ANY` renders
    /// as `<any>` and inline alternations render their options, so
    /// neither reads as a standalone type. Shapes (`$var` targets,
    /// `KEY=value` pairs) are validated in each command's `lower`, and
    /// the shape requirement lives in the argument description and
    /// command syntax.
    pub fn label(&self) -> String {
        match self {
            ArgType::String => "STRING".to_string(),
            ArgType::Path => "PATH".to_string(),
            ArgType::Int => "INT".to_string(),
            ArgType::Duration => "DURATION".to_string(),
            ArgType::List => "LIST".to_string(),
            ArgType::Any => "<any>".to_string(),
            ArgType::OneOf(options) => options.join("|"),
            ArgType::Rest(inner) => format!("{}...", inner.label()),
        }
    }

    /// Anchor of the type's reference section. Only types with a value-type
    /// reference section link; `<any>` and inline alternations render
    /// unlinked.
    pub fn anchor(&self) -> Option<String> {
        match self {
            ArgType::String => Some(crate::value::type_anchor("STRING")),
            ArgType::Path => Some(crate::value::type_anchor("PATH")),
            ArgType::Int => Some(crate::value::type_anchor("INT")),
            ArgType::Duration => Some(crate::value::type_anchor("DURATION")),
            ArgType::List => Some(crate::value::type_anchor("LIST")),
            ArgType::Any => None,
            ArgType::OneOf(_) => None,
            ArgType::Rest(inner) => inner.anchor(),
        }
    }

    /// Validate a statically-known literal against this type.
    /// Templates and variables are never passed here : see `check_arg`.
    pub fn validate_literal(&self, literal: &str) -> Result<()> {
        match self {
            ArgType::String | ArgType::Path | ArgType::Any => Ok(()),
            ArgType::Int => strip_digit_separators(literal)
                .parse::<i64>()
                .map(|_| ())
                .map_err(|_| anyhow!("expected int, got {literal:?}")),
            ArgType::Duration => parse_duration(literal).map(|_| ()),
            ArgType::List => {
                if literal.starts_with('$') {
                    Ok(())
                } else {
                    bail!("expected $var, got {literal:?}")
                }
            }
            ArgType::OneOf(options) => {
                // Exact match only: lowercase spellings are rejected so
                // keyword arguments stay uppercase across the DSL.
                if options.contains(&literal) {
                    Ok(())
                } else {
                    bail!("expected one of {}, got {literal:?}", options.join("|"))
                }
            }
            ArgType::Rest(inner) => inner.validate_literal(literal),
        }
    }

    /// Classify one positional arg for lower-time checking.
    /// `Static` literals validate now; templates, variables (except a
    /// `$var` where `List` is required), and mixed fragments defer to the
    /// runtime resolvers, which see interpolated values.
    pub fn check_arg(&self, arg: &Arg) -> Result<CheckOutcome> {
        match arg {
            Arg::String(s, _) if !s.contains("{{") => {
                self.validate_literal(s)?;
                Ok(CheckOutcome::Static)
            }
            Arg::String(_, _) => Ok(CheckOutcome::Deferred),
            Arg::Parts(_) => Ok(CheckOutcome::Deferred),
            Arg::Expr(Expr::Var(_)) => {
                if matches!(*self, ArgType::List) {
                    Ok(CheckOutcome::Static)
                } else {
                    Ok(CheckOutcome::Deferred)
                }
            }
            Arg::Expr(_) => {
                if matches!(*self, ArgType::List) {
                    bail!("expected $var, got expression {}", arg.render())
                } else {
                    Ok(CheckOutcome::Deferred)
                }
            }
        }
    }
}

/// Lower-time checking outcome for one positional arg.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum CheckOutcome {
    /// Validated now; nothing deferred.
    Static,
    /// Unknowable until runtime (template, variable, or fragment);
    /// runtime resolvers enforce the type on the resolved value.
    Deferred,
}

/// Validate positional args against a command's declared specs.
/// Missing required positionals, statically-known type violations, and
/// trailing positionals beyond a fixed-arity spec all fail here;
/// templates, variables, and fragments defer to the runtime resolvers.
/// A trailing `Rest` spec absorbs any number of positionals.
pub fn validate_positionals_against_meta(
    cmd_name: &str,
    specs: &[ArgSpec],
    args: &[Arg],
) -> Result<(), ParseError> {
    let has_rest = specs
        .last()
        .is_some_and(|s| matches!(s.arg_type, ArgType::Rest(_)));

    if !has_rest && args.len() > specs.len() {
        return Err(ParseError::validation(
            cmd_name,
            format!(
                "invalid syntax for command {cmd_name}: expects at most {} positional argument(s), got {}",
                specs.len(),
                args.len()
            ),
            &SpanContext::line_only(0),
        ));
    }

    for spec in specs {
        if let ArgType::Rest(inner) = spec.arg_type {
            // Variadic tail: every trailing positional checks against
            // the inner type, not just the first.
            let tail = args.get(spec.index..).unwrap_or(&[]);
            if tail.is_empty() && spec.required {
                return Err(ParseError::validation(
                    cmd_name,
                    format!(
                        "invalid syntax for command {cmd_name}: requires argument `{}`",
                        spec.name
                    ),
                    &SpanContext::line_only(0),
                ));
            }
            for arg in tail {
                check_one(cmd_name, spec, inner, arg)?;
            }
            return Ok(());
        }
        match args.get(spec.index) {
            Some(arg) => check_one(cmd_name, spec, &spec.arg_type, arg)?,
            None if spec.required => {
                return Err(ParseError::validation(
                    cmd_name,
                    format!(
                        "invalid syntax for command {cmd_name}: requires argument `{}`",
                        spec.name
                    ),
                    &SpanContext::line_only(0),
                ));
            }
            None => {}
        }
    }
    Ok(())
}

fn check_one(
    cmd_name: &str,
    spec: &ArgSpec,
    arg_type: &ArgType,
    arg: &Arg,
) -> Result<(), ParseError> {
    match arg_type.check_arg(arg) {
        Ok(_) => Ok(()),
        Err(e) => Err(ParseError::validation(
            cmd_name,
            format!(
                "invalid syntax for command {cmd_name}: argument `{}` got {} — {e:#}",
                spec.name,
                arg.render()
            ),
            &SpanContext::line_only(0),
        )),
    }
}

/// Strip one layer of surrounding `"` or `'` quotes (both kinds, everywhere).
pub fn strip_surrounding_quotes(value: &str) -> &str {
    value
        .strip_prefix('"')
        .and_then(|s| s.strip_suffix('"'))
        .or_else(|| value.strip_prefix('\'').and_then(|s| s.strip_suffix('\'')))
        .unwrap_or(value)
}

/// Single-token `KEY=value` split for direct `lower_command` callers and
/// exotic keys the grammar cannot classify (single tokens only : no whitespace
/// reassembly, so the quoted-space corruption class cannot arise here).
/// Returns `Ok(None)` when there is no `=`.
pub fn split_assignment(text: &str) -> Result<Option<(String, Arg)>> {
    let Some((key, raw)) = text.split_once('=') else {
        return Ok(None);
    };
    if key.is_empty() {
        bail!("assignment requires KEY=value format");
    }
    Ok(Some((
        key.to_string(),
        Arg::String(strip_surrounding_quotes(raw).to_string(), false),
    )))
}

/// Parse a TIMEOUT duration token (`500ms`, `10s`, `2m`, `1h`; a bare
/// number means seconds). One optional space may separate the number
/// from its unit (`30 s`), like byte counts: bare DSL tokens still
/// split upstream, so this covers quoted strings and variables.
pub fn parse_duration(s: &str) -> Result<std::time::Duration> {
    let s = join_single_space(s)?;
    let (digits, unit_ms): (&str, u64) = if let Some(v) = s.strip_suffix("ms") {
        (v, 1)
    } else if let Some(v) = s.strip_suffix('s') {
        (v, 1_000)
    } else if let Some(v) = s.strip_suffix('m') {
        (v, 60_000)
    } else if let Some(v) = s.strip_suffix('h') {
        (v, 3_600_000)
    } else {
        (s.as_str(), 1_000)
    };
    let n: u64 = digits
        .parse()
        .map_err(|_| anyhow!("invalid TIMEOUT duration: {s}"))?;
    let millis = n
        .checked_mul(unit_ms)
        .ok_or_else(|| anyhow!("TIMEOUT duration out of range: {s}"))?;
    if millis == 0 {
        bail!("TIMEOUT duration must be positive, got: {s}");
    }
    Ok(std::time::Duration::from_millis(millis))
}

/// Canonical display for a duration: largest exact unit (`500ms`, `10s`,
/// `2m`, `1h`), falling back to milliseconds. Round-trips through
/// [`parse_duration`].
pub fn format_duration(d: &std::time::Duration) -> String {
    let millis = d.as_millis();
    if millis.is_multiple_of(3_600_000) {
        format!("{}h", millis / 3_600_000)
    } else if millis.is_multiple_of(60_000) {
        format!("{}m", millis / 60_000)
    } else if millis.is_multiple_of(1_000) {
        format!("{}s", millis / 1_000)
    } else {
        format!("{millis}ms")
    }
}

/// Strip Rust-style `_` digit separators when well-formed (digits and
/// at most one `.`, separators only between digits, never leading,
/// trailing, or doubled, with an optional leading `+`/`-` sign passing
/// through for signed domains); otherwise return the text untouched so
/// the caller's own parse decides. The single rule behind every
/// string-to-number coercion (`INT` validation, assertion operands,
/// byte counts), so `1_000_000` and `-1_000` read identically everywhere
/// while `1__0` and `1_` never silently become numbers. Unsigned
/// callers still reject `-` at parse time; `+` parses like every other
/// Rust-parsed number in the DSL.
pub fn strip_digit_separators(text: &str) -> String {
    let body = text
        .strip_prefix('+')
        .or_else(|| text.strip_prefix('-'))
        .unwrap_or(text);
    let bytes = body.as_bytes();
    let well_formed = !body.is_empty()
        && bytes[0].is_ascii_digit()
        && bytes[bytes.len() - 1].is_ascii_digit()
        && bytes
            .iter()
            .all(|b| b.is_ascii_digit() || *b == b'_' || *b == b'.')
        && !body.contains("__")
        && body.bytes().filter(|b| *b == b'.').count() <= 1;
    if well_formed {
        text.replace('_', "")
    } else {
        text.to_string()
    }
}

/// Join a numeric token whose unit may ride separated by one space
/// (`1 GB`, `30 s`): surrounding whitespace trims, and exactly two
/// whitespace-separated parts rejoin digit-run plus unit. Anything else
/// (three parts, a split digit run like `1 0`, an empty string) fails:
/// the space may only separate the number from its unit, never split
/// the digits themselves.
fn join_single_space(s: &str) -> Result<String> {
    let mut parts = s.split_whitespace();
    let (first, second) = (parts.next(), parts.next());
    if parts.next().is_some() {
        bail!("invalid numeric token: {s}");
    }
    match (first, second) {
        (Some(digits), None) => Ok(digits.to_string()),
        (Some(digits), Some(unit))
            if digits
                .strip_prefix('+')
                .unwrap_or(digits)
                .bytes()
                .all(|b| b.is_ascii_digit() || b == b'_')
                && unit.bytes().all(|b| b.is_ascii_alphabetic()) =>
        {
            Ok(format!("{digits}{unit}"))
        }
        _ => bail!("invalid numeric token: {s}"),
    }
}

/// Parse a byte-count token (`500`, `500B`, `10KB`, `2MB`, `1GB`, `1TB`
/// decimal; `10KIB`, `2MIB`, `1GIB`, `1TIB` binary; a bare number means
/// bytes). Digit runs may group with `_` separators (`1_000_000`),
/// Rust-literal style: leading, trailing, and doubled separators fail.
/// One optional space may separate the number from its unit (`1 GB`);
/// anything more stays rejected, and bare DSL tokens still split
/// upstream (this covers quoted strings, variables, and flag values).
/// Fractions stay rejected by design (`1.5GB` fails: float parsing
/// cannot hold exact byte boundaries past 2^53, and every sub-unit has
/// an exact integer spelling like `1500MB`). Matching is
/// case-insensitive (`1gb`, `1GB`, and `1Gb` agree), mirroring
/// [`parse_duration`]: digits only, no fractions, no signs.
pub fn parse_byte_count(s: &str) -> Result<u64> {
    let compact = join_single_space(s)?;
    let s = compact.as_str();
    let lower = s.to_ascii_lowercase();
    let (digits, unit): (&str, u64) = if let Some(v) = lower.strip_suffix("kib") {
        (v, 1 << 10)
    } else if let Some(v) = lower.strip_suffix("mib") {
        (v, 1 << 20)
    } else if let Some(v) = lower.strip_suffix("gib") {
        (v, 1 << 30)
    } else if let Some(v) = lower.strip_suffix("tib") {
        (v, 1 << 40)
    } else if let Some(v) = lower.strip_suffix("kb") {
        (v, 1_000)
    } else if let Some(v) = lower.strip_suffix("mb") {
        (v, 1_000_000)
    } else if let Some(v) = lower.strip_suffix("gb") {
        (v, 1_000_000_000)
    } else if let Some(v) = lower.strip_suffix("tb") {
        (v, 1_000_000_000_000)
    } else if let Some(v) = lower.strip_suffix('b') {
        (v, 1)
    } else {
        (lower.as_str(), 1)
    };
    // Suffixes strip from the lowercased copy; slice the original at
    // the same boundary so errors echo the caller's spelling.
    // Separators follow the shared rule, so `1_0KB` parses while
    // `1__0KB` fails like everywhere else. A leading `+` strips before
    // the unsigned parse (`u64` rejects it; `-` still fails below).
    let digits = strip_digit_separators(&s[..digits.len()]);
    let digits = digits.strip_prefix('+').unwrap_or(&digits);
    let n: u64 = digits
        .parse()
        .map_err(|_| anyhow!("invalid byte count: {s}"))?;
    let bytes = n
        .checked_mul(unit)
        .ok_or_else(|| anyhow!("byte count out of range: {s}"))?;
    if bytes == 0 {
        bail!("byte count must be positive, got: {s}");
    }
    Ok(bytes)
}

/// Canonical display for a byte count: largest exact unit (`500B`,
/// `10KB`, `2MB`, `1GB`, binary `10KIB` and friends), falling back to
/// bytes. Round-trips through [`parse_byte_count`].
pub fn format_byte_count(n: u64) -> String {
    const TIB: u64 = 1 << 40;
    const TB: u64 = 1_000_000_000_000;
    const GIB: u64 = 1 << 30;
    const GB: u64 = 1_000_000_000;
    const MIB: u64 = 1 << 20;
    const MB: u64 = 1_000_000;
    const KIB: u64 = 1 << 10;
    const KB: u64 = 1_000;
    if n >= TIB && n.is_multiple_of(TIB) {
        format!("{}TiB", n / TIB)
    } else if n >= TB && n.is_multiple_of(TB) {
        format!("{}TB", n / TB)
    } else if n >= GIB && n.is_multiple_of(GIB) {
        format!("{}GiB", n / GIB)
    } else if n >= GB && n.is_multiple_of(GB) {
        format!("{}GB", n / GB)
    } else if n >= MIB && n.is_multiple_of(MIB) {
        format!("{}MiB", n / MIB)
    } else if n >= MB && n.is_multiple_of(MB) {
        format!("{}MB", n / MB)
    } else if n >= KIB && n.is_multiple_of(KIB) {
        format!("{}KiB", n / KIB)
    } else if n >= KB && n.is_multiple_of(KB) {
        format!("{}KB", n / KB)
    } else {
        format!("{n}B")
    }
}

/// Data direction for an argument.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum IoDirection {
    Read,
    Write,
}

/// Stream type for fallback or default output.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Stream {
    Stdin,
    Stdout,
    Stderr,
}

/// Metadata for a single flag.
pub struct FlagSpec {
    pub name: &'static str,
    pub long: &'static str,
    pub value_type: FlagValueType,
    pub required: bool,
    pub description: &'static str,
}

/// Type of value a flag accepts.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum FlagValueType {
    /// Boolean flag (no value required).
    Flag,
    /// String-valued flag.
    String,
    /// Integer-valued flag.
    Int,
}

impl FlagValueType {
    /// Display label using the type vocabulary. A bare `Flag`
    /// switch carries no value; `BOOL` names what its presence asserts.
    pub fn label(&self) -> &'static str {
        match self {
            FlagValueType::Flag => "BOOL",
            FlagValueType::String => "STRING",
            FlagValueType::Int => "INT",
        }
    }
}

/// Complete metadata for a command.
pub struct CommandMeta {
    pub name: &'static str,
    pub syntax: &'static str,
    pub summary: &'static str,
    pub description: &'static str,
    pub args: &'static [ArgSpec],
    pub flags: &'static [FlagSpec],
    pub default_output: Option<Stream>,
    pub examples: &'static [Example],
}

/// An executable example for a command or function.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Example {
    pub name: &'static str,
    pub fence_meta: Option<&'static str>,
    pub code: &'static str,
}

/// Trait for command metadata and lowering. No execution types.
///
/// This trait lives in `oxdock-parser` and has zero dependencies on
/// `oxdock-core`. Execution dispatch is handled separately by the
/// `define_pipeline!` macro in `oxdock-core`.
pub trait CommandSpec {
    const NAME: &'static str;

    fn metadata() -> CommandMeta;
    fn lower(flags: Vec<(String, Arg)>, args: Vec<Arg>) -> Result<StepKind>;
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ast::Expr;

    fn lit(text: &str) -> Arg {
        Arg::String(text.to_string(), false)
    }

    fn var(name: &str) -> Arg {
        Arg::Expr(Expr::Var(name.to_string()))
    }

    #[test]
    fn validate_literal_covers_each_variant() {
        ArgType::String.check_arg(&lit("anything at all")).unwrap();
        ArgType::Path.check_arg(&lit("a/b/../c")).unwrap();
        ArgType::Int.check_arg(&lit("3")).unwrap();
        assert!(ArgType::Int.check_arg(&lit("banana")).is_err());
        ArgType::Duration.check_arg(&lit("10s")).unwrap();
        ArgType::Duration.check_arg(&lit("30")).unwrap();
        assert!(ArgType::Duration.check_arg(&lit("banana")).is_err());
        assert!(ArgType::Duration.check_arg(&lit("0s")).is_err());
        ArgType::List.check_arg(&lit("$x")).unwrap();
        assert!(ArgType::List.check_arg(&lit("x")).is_err());
        // Only app types plus the visibly-marked placeholder remain.
        assert_eq!(ArgType::Any.label(), "<any>");
        ArgType::OneOf(&["SNAPSHOT", "LOCAL"])
            .check_arg(&lit("LOCAL"))
            .unwrap();
        // Lowercase spellings are rejected: keyword arguments stay uppercase.
        assert!(
            ArgType::OneOf(&["SNAPSHOT", "LOCAL"])
                .check_arg(&lit("local"))
                .is_err()
        );
        assert!(
            ArgType::OneOf(&["SNAPSHOT", "LOCAL"])
                .check_arg(&lit("REMOTE"))
                .is_err()
        );
    }

    #[test]
    fn check_arg_defers_dynamics_and_enforces_var() {
        // Templates defer: their values only exist after interpolation.
        assert_eq!(
            ArgType::Duration.check_arg(&lit("{{ $d }}")).unwrap(),
            CheckOutcome::Deferred
        );
        // Variables satisfy List statically and defer for everything else.
        assert_eq!(
            ArgType::List.check_arg(&var("x")).unwrap(),
            CheckOutcome::Static
        );
        assert_eq!(
            ArgType::Duration.check_arg(&var("d")).unwrap(),
            CheckOutcome::Deferred
        );
        // Non-variable expressions where a $var is required fail at lower.
        let list = Arg::Expr(Expr::List(vec![]));
        assert!(ArgType::List.check_arg(&list).is_err());
        assert_eq!(
            ArgType::String.check_arg(&list).unwrap(),
            CheckOutcome::Deferred
        );
        assert_eq!(ArgType::List.label(), "LIST");
        // `$var` shapes are enforced per command in `lower`, not here:
        // a bare word passes the String check and fails lowering.
        assert_eq!(
            ArgType::String.check_arg(&lit("x")).unwrap(),
            CheckOutcome::Static
        );
    }

    fn spec(index: usize, required: bool, arg_type: ArgType) -> ArgSpec {
        ArgSpec {
            name: "p",
            arg_type,
            description: "",
            io: IoDirection::Write,
            index,
            required,
            fallback_stream: None,
        }
    }

    #[test]
    fn positionals_enforce_required_and_rest_tails() {
        let specs = [spec(0, true, ArgType::Int)];
        assert!(validate_positionals_against_meta("T", &specs, &[]).is_err());
        assert!(validate_positionals_against_meta("T", &specs, &[lit("3")]).is_ok());
        assert!(validate_positionals_against_meta("T", &specs, &[lit("banana")]).is_err());

        // Rest validates EVERY trailing positional, not just the first.
        let specs = [ArgSpec {
            arg_type: ArgType::Rest(&ArgType::Int),
            ..spec(0, true, ArgType::Int)
        }];
        assert!(
            validate_positionals_against_meta("T", &specs, &[lit("1"), lit("2"), lit("banana")])
                .is_err()
        );
        assert!(validate_positionals_against_meta("T", &specs, &[lit("1"), lit("2")]).is_ok());
        // Extras beyond fixed-arity specs fail (no silent truncation).
        let specs = [spec(0, true, ArgType::Int)];
        let err = validate_positionals_against_meta("T", &specs, &[lit("1"), lit("extra")])
            .expect_err("extras must fail");
        assert!(
            err.to_string().contains("at most 1"),
            "unexpected error: {err:#}"
        );
    }
}