weavatrix-scan 0.4.3

use crate::default_file_types::DEFAULT_FILE_TYPES;
use crate::glob;
use std::collections::{BTreeMap, BTreeSet};
use std::path::Path;

/// Named, reusable groups of file-name or repository-relative glob patterns.
#[derive(Debug, Clone, Default, PartialEq, Eq)]
pub struct NamedFileTypes {
    definitions: BTreeMap<String, BTreeSet<FileTypePattern>>,
    selections: Vec<FileTypeSelection>,
}

#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
enum FileTypePattern {
    Extension(String),
    Glob(String),
}

#[derive(Debug, Clone, PartialEq, Eq)]
enum FileTypeSelection {
    Include(String),
    Exclude(String),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub(crate) enum FileTypeMatch {
    Include,
    Exclude,
    None,
}

impl NamedFileTypes {
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }

    /// Creates a catalog containing common source, markup, data, and build
    /// file types. No type is selected until [`Self::select`] is called.
    #[must_use]
    pub fn defaults() -> Self {
        Self::new().with_defaults()
    }

    /// Adds built-in definitions without replacing caller-defined names.
    #[must_use]
    pub fn with_defaults(mut self) -> Self {
        for &(names, patterns) in DEFAULT_FILE_TYPES {
            let parsed = patterns
                .iter()
                .map(|pattern| pattern_from_glob(pattern))
                .collect::<BTreeSet<_>>();
            for name in names {
                self.definitions
                    .entry((*name).to_owned())
                    .or_insert_with(|| parsed.clone());
            }
        }
        self
    }

    /// Adds or replaces a named extension group.
    ///
    /// Extensions retain a specialized allocation-free matching path.
    #[must_use]
    pub fn with_type<I, S>(mut self, name: impl Into<String>, extensions: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.definitions.insert(
            name.into(),
            extensions
                .into_iter()
                .map(|extension| {
                    FileTypePattern::Extension(normalized_extension(extension.as_ref()))
                })
                .collect(),
        );
        self
    }

    /// Adds or replaces a named group of arbitrary glob patterns.
    ///
    /// Patterns containing `/` match normalized repository-relative paths.
    /// Other patterns match only the native file name. Matching is
    /// case-sensitive; callers can include explicit variants when needed.
    #[must_use]
    pub fn with_globs<I, S>(mut self, name: impl Into<String>, patterns: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.definitions.insert(
            name.into(),
            patterns
                .into_iter()
                .map(|pattern| pattern_from_glob(pattern.as_ref()))
                .collect(),
        );
        self
    }

    /// Adds or replaces a type composed from existing definitions.
    ///
    /// Unknown component names contribute no patterns.
    #[must_use]
    pub fn with_composed_type<I, S>(mut self, name: impl Into<String>, components: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        let mut patterns = BTreeSet::new();
        for component in components {
            if let Some(component) = self.definitions.get(component.as_ref()) {
                patterns.extend(component.iter().cloned());
            }
        }
        self.definitions.insert(name.into(), patterns);
        self
    }

    /// Replaces current selections with included named groups.
    ///
    /// Unknown names simply match no files.
    #[must_use]
    pub fn select<I, S>(mut self, names: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.selections = names
            .into_iter()
            .map(|name| FileTypeSelection::Include(name.as_ref().to_owned()))
            .collect();
        self
    }

    /// Appends excluded named groups. Later matching selections win.
    #[must_use]
    pub fn negate<I, S>(mut self, names: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<str>,
    {
        self.selections.extend(
            names
                .into_iter()
                .map(|name| FileTypeSelection::Exclude(name.as_ref().to_owned())),
        );
        self
    }

    #[must_use]
    pub fn is_active(&self) -> bool {
        !self.selections.is_empty()
    }

    #[must_use]
    pub fn contains(&self, name: &str) -> bool {
        self.definitions.contains_key(name)
    }

    /// Returns the number of available named definitions.
    #[must_use]
    pub fn len(&self) -> usize {
        self.definitions.len()
    }

    /// Returns whether the catalog contains no named definitions.
    #[must_use]
    pub fn is_empty(&self) -> bool {
        self.definitions.is_empty()
    }

    /// Iterates over definition names in deterministic lexical order.
    pub fn names(&self) -> impl ExactSizeIterator<Item = &str> + DoubleEndedIterator {
        self.definitions.keys().map(String::as_str)
    }

    pub(crate) fn has_includes(&self) -> bool {
        self.selections
            .iter()
            .any(|selection| matches!(selection, FileTypeSelection::Include(_)))
    }

    pub(crate) fn matched(&self, path: &Path, relative: &str) -> FileTypeMatch {
        let mut matched = FileTypeMatch::None;
        for selection in &self.selections {
            let (name, decision) = match selection {
                FileTypeSelection::Include(name) => (name, FileTypeMatch::Include),
                FileTypeSelection::Exclude(name) => (name, FileTypeMatch::Exclude),
            };
            if self
                .definitions
                .get(name)
                .is_some_and(|patterns| matches_any(patterns, path, relative))
            {
                matched = decision;
            }
        }
        matched
    }
}

fn matches_any(patterns: &BTreeSet<FileTypePattern>, path: &Path, relative: &str) -> bool {
    let file_name = path.file_name().and_then(|value| value.to_str());
    patterns.iter().any(|pattern| match pattern {
        FileTypePattern::Extension(expected) => path
            .extension()
            .and_then(|value| value.to_str())
            .is_some_and(|actual| actual == expected || actual.eq_ignore_ascii_case(expected)),
        FileTypePattern::Glob(pattern) if pattern.contains('/') => glob::matches(pattern, relative),
        FileTypePattern::Glob(pattern) => {
            file_name.is_some_and(|file_name| glob::matches(pattern, file_name))
        }
    })
}

fn pattern_from_glob(pattern: &str) -> FileTypePattern {
    let normalized = pattern.replace('\\', "/");
    normalized
        .strip_prefix("*.")
        .filter(|extension| {
            !extension.contains('.')
                && !extension
                    .bytes()
                    .any(|byte| matches!(byte, b'*' | b'?' | b'[' | b'{' | b'/'))
        })
        .map_or_else(
            || FileTypePattern::Glob(normalized.clone()),
            |extension| FileTypePattern::Extension(normalized_extension(extension)),
        )
}

fn normalized_extension(extension: &str) -> String {
    extension.trim_start_matches('.').to_ascii_lowercase()
}

#[cfg(test)]
mod tests {
    use super::{NamedFileTypes, pattern_from_glob};

    #[test]
    fn defaults_include_every_ignore_name_and_pattern() {
        let ours = NamedFileTypes::defaults();
        let mut upstream = ignore::types::TypesBuilder::new();
        upstream.add_defaults();
        for definition in upstream.definitions() {
            let patterns = ours
                .definitions
                .get(definition.name())
                .unwrap_or_else(|| panic!("missing ignore type {}", definition.name()));
            for pattern in definition.globs() {
                assert!(
                    patterns.contains(&pattern_from_glob(pattern)),
                    "missing ignore pattern {}:{pattern}",
                    definition.name()
                );
            }
        }
    }
}