ryo-symbol 0.1.0

//! SymbolPathResolver - WorkspaceFilePath → SymbolPath conversion
//!
//! Centralizes the logic for converting file paths to symbol paths.
//! This is the reverse of FilePathResolver.

use crate::crate_name::CrateName;
use crate::error::ParseError;
use crate::file_path::WorkspaceFilePath;
use crate::path::SymbolPath;
use crate::resolver::{CrateLayout, EntryPoint};

/// Resolves WorkspaceFilePath to SymbolPath
///
/// # Design
///
/// This resolver centralizes the conversion from file paths to Rust symbol paths.
/// It wraps the crate name and layout, providing methods for bidirectional conversion
/// between file paths and symbol paths.
///
/// # Example
///
/// ```ignore
/// // For a crate in crates/ directory
/// let resolver = SymbolPathResolver::with_layout(
///     "my_crate",
///     CrateLayout::in_crates("my-crate"),
/// );
///
/// // Module path from file
/// let module = resolver.resolve_module(&file_path)?;
/// // → my_crate::foo::bar
///
/// // Reverse: symbol to file
/// let file = resolver.to_workspace_file_path(&symbol, &workspace_root);
/// // → crates/my-crate/src/foo/bar.rs
/// ```
#[derive(Debug, Clone)]
pub struct SymbolPathResolver {
    crate_name: CrateName,
    layout: CrateLayout,
    entry_point: EntryPoint,
}

impl SymbolPathResolver {
    /// Create a resolver for a crate (assumes Root layout and Lib entry point)
    ///
    /// For workspace crates in `crates/` directory, use `with_layout` instead.
    pub fn new(crate_name: impl AsRef<str>) -> Self {
        Self {
            crate_name: CrateName::new_unchecked(crate_name.as_ref()),
            layout: CrateLayout::Root,
            entry_point: EntryPoint::Lib,
        }
    }

    /// Create a resolver with explicit layout (assumes Lib entry point)
    ///
    /// # Example
    ///
    /// ```ignore
    /// // For crates/my-crate/src/*.rs
    /// let resolver = SymbolPathResolver::with_layout(
    ///     "my_crate",
    ///     CrateLayout::in_crates("my-crate"),
    /// );
    /// ```
    pub fn with_layout(crate_name: impl AsRef<str>, layout: CrateLayout) -> Self {
        Self {
            crate_name: CrateName::new_unchecked(crate_name.as_ref()),
            layout,
            entry_point: EntryPoint::Lib,
        }
    }

    /// Create a resolver with explicit layout and entry point
    ///
    /// # Example
    ///
    /// ```ignore
    /// // For a binary crate: crates/my-crate/src/main.rs
    /// let resolver = SymbolPathResolver::with_layout_and_entry(
    ///     "my_crate",
    ///     CrateLayout::in_crates("my-crate"),
    ///     EntryPoint::Bin,
    /// );
    /// ```
    pub fn with_layout_and_entry(
        crate_name: impl AsRef<str>,
        layout: CrateLayout,
        entry_point: EntryPoint,
    ) -> Self {
        Self {
            crate_name: CrateName::new_unchecked(crate_name.as_ref()),
            layout,
            entry_point,
        }
    }

    /// Create a resolver from a CrateName (assumes Root layout and Lib entry point)
    pub fn from_crate_name(crate_name: CrateName) -> Self {
        Self {
            crate_name,
            layout: CrateLayout::Root,
            entry_point: EntryPoint::Lib,
        }
    }

    /// Create a resolver from a CrateName with explicit layout (assumes Lib entry point)
    pub fn from_crate_name_with_layout(crate_name: CrateName, layout: CrateLayout) -> Self {
        Self {
            crate_name,
            layout,
            entry_point: EntryPoint::Lib,
        }
    }

    /// Create a resolver from a CrateName with explicit layout and entry point
    pub fn from_crate_name_with_layout_and_entry(
        crate_name: CrateName,
        layout: CrateLayout,
        entry_point: EntryPoint,
    ) -> Self {
        Self {
            crate_name,
            layout,
            entry_point,
        }
    }

    /// Create a resolver from a WorkspaceFilePath
    ///
    /// Extracts the crate name and infers both layout and entry point from the file path.
    pub fn from_workspace_path(path: &WorkspaceFilePath) -> Result<Self, ParseError> {
        Ok(Self {
            crate_name: path.crate_name().clone(),
            layout: CrateLayout::from_workspace_file_path(path),
            entry_point: EntryPoint::from_path(path.as_relative()),
        })
    }

    /// Get the crate name
    pub fn crate_name(&self) -> &CrateName {
        &self.crate_name
    }

    /// Get the entry point
    pub fn entry_point(&self) -> EntryPoint {
        self.entry_point
    }

    /// Get the crate layout
    pub fn layout(&self) -> &CrateLayout {
        &self.layout
    }

    /// Resolve file path to module path (SymbolPath)
    ///
    /// e.g., "src/foo/bar.rs" → "my_crate::foo::bar"
    pub fn resolve_module(&self, path: &WorkspaceFilePath) -> Result<SymbolPath, ParseError> {
        SymbolPath::from_file_path(&self.crate_name, path)
    }

    /// Resolve item in file
    ///
    /// e.g., "src/lib.rs" + "MyStruct" → "my_crate::MyStruct"
    pub fn resolve_item(
        &self,
        path: &WorkspaceFilePath,
        item_name: &str,
    ) -> Result<SymbolPath, ParseError> {
        let module = self.resolve_module(path)?;
        module.child(item_name)
    }

    /// Resolve nested item in file
    ///
    /// e.g., "src/lib.rs" + ["Foo", "new"] → "my_crate::Foo::new"
    pub fn resolve_nested(
        &self,
        path: &WorkspaceFilePath,
        segments: &[&str],
    ) -> Result<SymbolPath, ParseError> {
        let mut current = self.resolve_module(path)?;
        for seg in segments {
            current = current.child(*seg)?;
        }
        Ok(current)
    }

    /// Get module path string (without parsing to SymbolPath)
    ///
    /// Useful when you need the string representation directly.
    pub fn module_path_str(&self, path: &WorkspaceFilePath) -> String {
        SymbolPath::module_path_str(path)
    }

    // ========================================================================
    // Reverse conversion: SymbolPath → WorkspaceFilePath
    // ========================================================================

    /// Convert SymbolPath to WorkspaceFilePath (reverse of resolve_module)
    ///
    /// Determines the file path where a symbol should be defined.
    ///
    /// # Rules
    ///
    /// - `crate` → `src/lib.rs`
    /// - `crate::Item` → `src/lib.rs` (item in crate root)
    /// - `crate::foo::Item` → `src/foo.rs` (item in module foo)
    /// - `crate::foo::bar::Item` → `src/foo/bar.rs` (item in nested module)
    ///
    /// # Arguments
    ///
    /// - `path`: The symbol path to convert
    /// - `workspace_root`: The workspace root for creating WorkspaceFilePath
    ///
    /// # Example
    ///
    /// ```ignore
    /// let resolver = SymbolPathResolver::new("my_crate");
    /// let symbol = SymbolPath::parse("my_crate::models::User")?;
    /// let file = resolver.to_workspace_file_path(&symbol, &workspace_root);
    /// // → src/models.rs
    /// ```
    pub fn to_workspace_file_path(
        &self,
        symbol_path: &SymbolPath,
        workspace_root: std::sync::Arc<std::path::Path>,
    ) -> WorkspaceFilePath {
        let relative = self.symbol_path_to_relative(symbol_path);
        WorkspaceFilePath::new_unchecked(
            std::path::PathBuf::from(relative),
            workspace_root,
            self.crate_name.clone(),
        )
    }

    /// Convert SymbolPath to relative file path string
    ///
    /// This is the core logic for reverse conversion.
    /// Uses the crate layout and entry point to determine the correct path.
    pub fn symbol_path_to_relative(&self, symbol_path: &SymbolPath) -> String {
        let depth = symbol_path.depth();
        let src_dir = self.layout.src_dir();
        let src_prefix = src_dir.to_string_lossy();
        let entry_file = self.entry_point.file_name();

        // Handle edge cases
        if depth == 0 {
            return format!("{}/{}", src_prefix, entry_file);
        }

        // depth 1: crate → {src}/{entry} (lib.rs or main.rs)
        // depth 2: crate::Item → {src}/{entry}
        // depth 3: crate::mod::Item → {src}/mod.rs
        // depth 4: crate::mod1::mod2::Item → {src}/mod1/mod2.rs

        match depth {
            0..=2 => format!("{}/{}", src_prefix, entry_file),
            _ => {
                // Module segments are from index 1 to (depth - 2) inclusive
                // For depth=3: segments[1] is the module
                // For depth=4: segments[1], segments[2] are the modules (but last one is in parent)
                //
                // Actually, let's think about this more carefully:
                // crate::foo::Bar (depth=3) → item Bar is in module foo → {src}/foo.rs
                // crate::foo::bar::Baz (depth=4) → item Baz is in module foo::bar → {src}/foo/bar.rs
                //
                // So we need segments from 1 to (depth - 2) for the file path

                let mut parts = Vec::new();
                for i in 1..=(depth - 2) {
                    if let Some(seg) = symbol_path.segment(i) {
                        parts.push(seg.name().to_string());
                    }
                }

                if parts.is_empty() {
                    format!("{}/{}", src_prefix, entry_file)
                } else {
                    format!("{}/{}.rs", src_prefix, parts.join("/"))
                }
            }
        }
    }
}

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

    fn make_path(relative: &str) -> WorkspaceFilePath {
        WorkspaceFilePath::new_for_test(relative, "/workspace", "my_crate")
    }

    #[test]
    fn test_new() {
        let resolver = SymbolPathResolver::new("my_crate");
        assert_eq!(resolver.crate_name().as_str(), "my_crate");
    }

    #[test]
    fn test_from_workspace_path() {
        let path = make_path("src/lib.rs");
        let resolver = SymbolPathResolver::from_workspace_path(&path).unwrap();
        assert_eq!(resolver.crate_name().as_str(), "my_crate");
    }

    #[test]
    fn test_resolve_module_lib() {
        let resolver = SymbolPathResolver::new("my_crate");
        let path = make_path("src/lib.rs");
        let symbol = resolver.resolve_module(&path).unwrap();
        assert_eq!(symbol.to_string(), "my_crate");
    }

    #[test]
    fn test_resolve_module_nested() {
        let resolver = SymbolPathResolver::new("my_crate");
        let path = make_path("src/foo/bar.rs");
        let symbol = resolver.resolve_module(&path).unwrap();
        assert_eq!(symbol.to_string(), "my_crate::foo::bar");
    }

    #[test]
    fn test_resolve_item() {
        let resolver = SymbolPathResolver::new("my_crate");
        let path = make_path("src/lib.rs");
        let symbol = resolver.resolve_item(&path, "MyStruct").unwrap();
        assert_eq!(symbol.to_string(), "my_crate::MyStruct");
    }

    #[test]
    fn test_resolve_nested() {
        let resolver = SymbolPathResolver::new("my_crate");
        let path = make_path("src/lib.rs");
        let symbol = resolver.resolve_nested(&path, &["Foo", "new"]).unwrap();
        assert_eq!(symbol.to_string(), "my_crate::Foo::new");
    }

    #[test]
    fn test_module_path_str() {
        let resolver = SymbolPathResolver::new("my_crate");
        let path = make_path("src/foo/bar.rs");
        assert_eq!(resolver.module_path_str(&path), "my_crate::foo::bar");
    }

    // ========================================================================
    // Reverse conversion tests
    // ========================================================================

    #[test]
    fn test_symbol_path_to_relative_crate_root() {
        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate").unwrap();
        assert_eq!(resolver.symbol_path_to_relative(&symbol), "src/lib.rs");
    }

    #[test]
    fn test_symbol_path_to_relative_crate_item() {
        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate::Config").unwrap();
        assert_eq!(resolver.symbol_path_to_relative(&symbol), "src/lib.rs");
    }

    #[test]
    fn test_symbol_path_to_relative_module_item() {
        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate::models::User").unwrap();
        assert_eq!(resolver.symbol_path_to_relative(&symbol), "src/models.rs");
    }

    #[test]
    fn test_symbol_path_to_relative_nested_module() {
        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate::foo::bar::Baz").unwrap();
        assert_eq!(resolver.symbol_path_to_relative(&symbol), "src/foo/bar.rs");
    }

    #[test]
    fn test_symbol_path_to_relative_deep_nested() {
        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate::a::b::c::Item").unwrap();
        assert_eq!(resolver.symbol_path_to_relative(&symbol), "src/a/b/c.rs");
    }

    #[test]
    fn test_to_workspace_file_path() {
        use std::path::Path;
        use std::sync::Arc;

        let resolver = SymbolPathResolver::new("test_crate");
        let symbol = SymbolPath::parse("test_crate::models::User").unwrap();
        let workspace_root = Arc::from(Path::new("/project"));

        let file_path = resolver.to_workspace_file_path(&symbol, workspace_root);
        assert_eq!(file_path.as_relative().to_str().unwrap(), "src/models.rs");
    }

    #[test]
    fn test_roundtrip_conversion() {
        use std::path::Path;
        use std::sync::Arc;

        let resolver = SymbolPathResolver::new("my_crate");
        let workspace_root = Arc::from(Path::new("/project"));

        // Forward: file → symbol
        let original_file = make_path("src/foo/bar.rs");
        let symbol = resolver.resolve_module(&original_file).unwrap();
        assert_eq!(symbol.to_string(), "my_crate::foo::bar");

        // Add an item
        let item_symbol = symbol.child("MyStruct").unwrap();
        assert_eq!(item_symbol.to_string(), "my_crate::foo::bar::MyStruct");

        // Reverse: symbol → file
        let recovered_file = resolver.to_workspace_file_path(&item_symbol, workspace_root);
        assert_eq!(
            recovered_file.as_relative().to_str().unwrap(),
            "src/foo/bar.rs"
        );
    }

    // ========================================================================
    // CrateLayout tests
    // ========================================================================

    #[test]
    fn test_with_layout_in_crates() {
        let resolver =
            SymbolPathResolver::with_layout("my_crate", CrateLayout::in_crates("my-crate"));
        let symbol = SymbolPath::parse("my_crate::Config").unwrap();
        assert_eq!(
            resolver.symbol_path_to_relative(&symbol),
            "crates/my-crate/src/lib.rs"
        );
    }

    #[test]
    fn test_with_layout_in_crates_nested() {
        let resolver =
            SymbolPathResolver::with_layout("my_crate", CrateLayout::in_crates("my-crate"));
        let symbol = SymbolPath::parse("my_crate::models::User").unwrap();
        assert_eq!(
            resolver.symbol_path_to_relative(&symbol),
            "crates/my-crate/src/models.rs"
        );
    }

    #[test]
    fn test_with_layout_custom() {
        let resolver =
            SymbolPathResolver::with_layout("my_crate", CrateLayout::custom("packages/core"));
        let symbol = SymbolPath::parse("my_crate::models::User").unwrap();
        assert_eq!(
            resolver.symbol_path_to_relative(&symbol),
            "packages/core/src/models.rs"
        );
    }

    #[test]
    fn test_from_workspace_path_infers_layout() {
        let path =
            WorkspaceFilePath::new_for_test("crates/my-crate/src/lib.rs", "/workspace", "my_crate");
        let resolver = SymbolPathResolver::from_workspace_path(&path).unwrap();

        assert_eq!(resolver.crate_name().as_str(), "my_crate");
        assert_eq!(
            resolver.layout(),
            &CrateLayout::InCrates {
                crate_dir_name: "my-crate".to_string()
            }
        );
    }

    #[test]
    fn test_roundtrip_with_workspace_layout() {
        use std::path::Path;
        use std::sync::Arc;

        // Create resolver with workspace layout
        let resolver =
            SymbolPathResolver::with_layout("my_crate", CrateLayout::in_crates("my-crate"));
        let workspace_root = Arc::from(Path::new("/project"));

        // Symbol → File
        let symbol = SymbolPath::parse("my_crate::foo::bar::Item").unwrap();
        let file = resolver.to_workspace_file_path(&symbol, workspace_root);

        assert_eq!(
            file.as_relative().to_str().unwrap(),
            "crates/my-crate/src/foo/bar.rs"
        );
    }
}