ryo-symbol 0.1.0

//! Self-contained workspace file path

use std::ffi::OsStr;
use std::hash::{Hash, Hasher};
use std::io;
use std::path::{Path, PathBuf};
use std::sync::Arc;

use serde::de::{DeserializeSeed, Deserializer, MapAccess, Visitor};
use serde::ser::{Serialize, SerializeStruct, Serializer};

use crate::crate_name::CrateName;

/// Normalized relative path from workspace root (self-contained)
///
/// # Design
///
/// This type holds the relative path, workspace root, and crate name, making it
/// completely self-contained. You can get the absolute path and derive symbol
/// paths without any external context or provider.
///
/// - `relative`: Path from workspace_root (used for Hash/Eq/Serialize)
/// - `workspace_root`: Shared workspace root (Arc for lightweight sharing)
/// - `crate_name`: The crate this file belongs to (required)
///
/// # Creation
///
/// **Always create via `WorkspacePathResolver`**. Direct construction
/// with `new_unchecked()` is for internal/test use only.
///
/// ```ignore
/// let resolver = WorkspacePathResolver::new("/path/to/workspace".into());
/// let path = resolver.resolve("src/lib.rs")?;
/// ```
#[derive(Debug, Clone)]
pub struct WorkspaceFilePath {
    relative: PathBuf,
    workspace_root: Arc<Path>,
    crate_name: CrateName,
}

impl WorkspaceFilePath {
    /// Internal constructor (for normalized paths only)
    pub(crate) fn new_unchecked(
        relative: PathBuf,
        workspace_root: Arc<Path>,
        crate_name: CrateName,
    ) -> Self {
        Self {
            relative,
            workspace_root,
            crate_name,
        }
    }

    /// Test utility constructor (available with test-utils feature)
    #[cfg(any(test, feature = "test-utils"))]
    pub fn new_for_test(
        relative: impl Into<PathBuf>,
        workspace_root: impl Into<PathBuf>,
        crate_name: impl AsRef<str>,
    ) -> Self {
        Self {
            relative: relative.into(),
            workspace_root: Arc::from(workspace_root.into()),
            crate_name: CrateName::new_for_test(crate_name.as_ref()),
        }
    }

    /// Get the relative path
    pub fn as_relative(&self) -> &Path {
        &self.relative
    }

    /// Get the workspace root
    pub fn workspace_root(&self) -> &Path {
        &self.workspace_root
    }

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

    /// Get absolute path (no I/O, self-contained)
    pub fn to_absolute(&self) -> PathBuf {
        self.workspace_root.join(&self.relative)
    }

    /// Get canonicalized absolute path (with I/O)
    pub fn canonicalize(&self) -> io::Result<PathBuf> {
        std::fs::canonicalize(self.to_absolute())
    }

    /// Get the file name
    pub fn file_name(&self) -> Option<&OsStr> {
        self.relative.file_name()
    }

    /// Get the file extension
    pub fn extension(&self) -> Option<&OsStr> {
        self.relative.extension()
    }

    /// Get the parent directory
    pub fn parent(&self) -> Option<&Path> {
        self.relative.parent()
    }

    /// Check if this is a Rust source file
    pub fn is_rust_file(&self) -> bool {
        self.extension().is_some_and(|ext| ext == "rs")
    }

    /// Check if this is a binary entry point (main.rs or src/bin/*.rs)
    ///
    /// Binary entry points are handled separately from library code because:
    /// - `main.rs` and `lib.rs` both map to the crate root in module path terms
    /// - They represent different logical crates (binary vs library)
    /// - Storing them together causes data overwrite issues
    ///
    /// # Returns
    /// `true` if this file is:
    /// - `src/main.rs` or `*/src/main.rs`
    /// - `src/bin/*.rs` or `*/src/bin/*.rs`
    pub fn is_binary_entry(&self) -> bool {
        let path_str = self.relative.to_string_lossy();

        // Check for main.rs
        if path_str.ends_with("/main.rs") || path_str == "main.rs" {
            return true;
        }

        // Check for src/bin/*.rs pattern
        if path_str.contains("/bin/") && path_str.ends_with(".rs") {
            return true;
        }

        false
    }

    /// Create a new WorkspaceFilePath with different context
    ///
    /// This is useful after deserialization when both workspace_root and crate_name
    /// need to be set or updated.
    pub fn with_context(&self, workspace_root: Arc<Path>, crate_name: CrateName) -> Self {
        Self {
            relative: self.relative.clone(),
            workspace_root,
            crate_name,
        }
    }

    /// Create a new WorkspaceFilePath with different relative path
    ///
    /// This is useful for creating sibling files (e.g., creating `src/storage.rs`
    /// when you have `src/lib.rs`). The workspace_root and crate_name are inherited
    /// from the original path.
    ///
    /// # Example
    /// ```ignore
    /// let lib_rs = resolver.resolve("src/lib.rs")?;
    /// let storage_rs = lib_rs.with_relative("src/storage.rs");
    /// ```
    pub fn with_relative(&self, relative: impl Into<PathBuf>) -> Self {
        Self {
            relative: relative.into(),
            workspace_root: self.workspace_root.clone(),
            crate_name: self.crate_name.clone(),
        }
    }

    /// Create a sibling file in the same directory
    ///
    /// This is useful for creating module files (e.g., creating `src/storage.rs`
    /// when you have `src/lib.rs`).
    ///
    /// # Example
    /// ```ignore
    /// let lib_rs = resolver.resolve("src/lib.rs")?;
    /// let storage_rs = lib_rs.sibling("storage.rs");
    /// assert_eq!(storage_rs.as_relative(), Path::new("src/storage.rs"));
    /// ```
    pub fn sibling(&self, file_name: &str) -> Self {
        let parent = self.relative.parent().unwrap_or(Path::new(""));
        let new_relative = parent.join(file_name);
        self.with_relative(new_relative)
    }

    // === File I/O Operations ===

    /// Write content to this file, creating parent directories if needed
    ///
    /// This is the preferred way to write files in a workspace context.
    /// It automatically creates any missing parent directories before writing.
    ///
    /// # Example
    /// ```ignore
    /// let path = resolver.resolve("src/new_module/lib.rs")?;
    /// path.write("// New module\n")?;  // Creates src/new_module/ if needed
    /// ```
    pub fn write(&self, content: impl AsRef<[u8]>) -> io::Result<()> {
        write_with_parents(self.to_absolute(), content)
    }

    /// Read content from this file
    pub fn read(&self) -> io::Result<String> {
        std::fs::read_to_string(self.to_absolute())
    }

    /// Read content as bytes from this file
    pub fn read_bytes(&self) -> io::Result<Vec<u8>> {
        std::fs::read(self.to_absolute())
    }

    /// Check if the file exists
    pub fn exists(&self) -> bool {
        self.to_absolute().exists()
    }
}

/// Write content to a file, creating parent directories if needed
///
/// This is a standalone utility function for cases where you have a raw `PathBuf`
/// instead of a `WorkspaceFilePath`. Prefer using `WorkspaceFilePath::write()` when possible.
///
/// # Example
/// ```ignore
/// use ryo_symbol::write_with_parents;
///
/// write_with_parents("/path/to/new/file.rs", "content")?;
/// ```
pub fn write_with_parents(path: impl AsRef<Path>, content: impl AsRef<[u8]>) -> io::Result<()> {
    let path = path.as_ref();
    if let Some(parent) = path.parent() {
        if !parent.as_os_str().is_empty() && !parent.exists() {
            std::fs::create_dir_all(parent)?;
        }
    }
    std::fs::write(path, content)
}

// Hash/Eq based on relative path and crate_name (workspace_root is not included)
// This allows distinguishing files from different crates with the same relative path
// (e.g., "src/lib.rs" in crate-a vs crate-b)
impl PartialEq for WorkspaceFilePath {
    fn eq(&self, other: &Self) -> bool {
        self.relative == other.relative && self.crate_name == other.crate_name
    }
}

impl Eq for WorkspaceFilePath {}

impl Hash for WorkspaceFilePath {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.relative.hash(state);
        self.crate_name.hash(state);
    }
}

impl AsRef<Path> for WorkspaceFilePath {
    fn as_ref(&self) -> &Path {
        &self.relative
    }
}

impl std::fmt::Display for WorkspaceFilePath {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.relative.display())
    }
}

// === Serialization ===
//
// Serialize as a struct with "path" (POSIX format) and "crate_name".
// workspace_root is injected during deserialization via WorkspaceFilePathSeed.

impl Serialize for WorkspaceFilePath {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let mut state = serializer.serialize_struct("WorkspaceFilePath", 2)?;
        // Convert to POSIX format for cross-platform compatibility
        let posix_path = self.relative.to_string_lossy().replace('\\', "/");
        state.serialize_field("path", &posix_path)?;
        state.serialize_field("crate_name", &self.crate_name)?;
        state.end()
    }
}

// === Deserialization ===
//
// WorkspaceFilePath requires workspace_root context during deserialization.
// Use WorkspaceFilePathSeed with DeserializeSeed to inject the context.
// This is the responsibility of the Analysis layer, not Symbol layer.

/// Seed for deserializing WorkspaceFilePath with workspace_root injection
///
/// Since WorkspaceFilePath requires workspace_root which isn't stored in the
/// serialized form, use this seed to provide it during deserialization.
/// crate_name is stored in the serialized form and will be restored.
///
/// # Example
/// ```ignore
/// use serde::de::DeserializeSeed;
/// let seed = WorkspaceFilePathSeed::new(resolver.workspace_root_arc());
/// let path: WorkspaceFilePath = seed.deserialize(&mut deserializer)?;
/// ```
#[allow(dead_code)]
pub struct WorkspaceFilePathSeed {
    workspace_root: Arc<Path>,
}

impl WorkspaceFilePathSeed {
    /// Create a new seed with the workspace root
    #[allow(dead_code)]
    pub fn new(workspace_root: Arc<Path>) -> Self {
        Self { workspace_root }
    }
}

impl<'de> DeserializeSeed<'de> for WorkspaceFilePathSeed {
    type Value = WorkspaceFilePath;

    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct WorkspaceFilePathVisitor {
            workspace_root: Arc<Path>,
        }

        impl<'de> Visitor<'de> for WorkspaceFilePathVisitor {
            type Value = WorkspaceFilePath;

            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                formatter.write_str("a struct with 'path' and 'crate_name' fields")
            }

            fn visit_map<M>(self, mut map: M) -> Result<Self::Value, M::Error>
            where
                M: MapAccess<'de>,
            {
                let mut path: Option<String> = None;
                let mut crate_name: Option<CrateName> = None;

                while let Some(key) = map.next_key::<&str>()? {
                    match key {
                        "path" => path = Some(map.next_value()?),
                        "crate_name" => crate_name = Some(map.next_value()?),
                        _ => {
                            let _ = map.next_value::<serde::de::IgnoredAny>()?;
                        }
                    }
                }

                let path = path.ok_or_else(|| serde::de::Error::missing_field("path"))?;
                let crate_name =
                    crate_name.ok_or_else(|| serde::de::Error::missing_field("crate_name"))?;

                Ok(WorkspaceFilePath::new_unchecked(
                    PathBuf::from(path),
                    self.workspace_root,
                    crate_name,
                ))
            }
        }

        deserializer.deserialize_struct(
            "WorkspaceFilePath",
            &["path", "crate_name"],
            WorkspaceFilePathVisitor {
                workspace_root: self.workspace_root,
            },
        )
    }
}

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

    #[test]
    fn test_basic_operations() {
        let path = WorkspaceFilePath::new_for_test("src/lib.rs", "/workspace", "my_crate");

        assert_eq!(path.as_relative(), Path::new("src/lib.rs"));
        assert_eq!(path.workspace_root(), Path::new("/workspace"));
        assert_eq!(path.crate_name().as_str(), "my_crate");
        assert_eq!(path.to_absolute(), PathBuf::from("/workspace/src/lib.rs"));
        assert_eq!(path.file_name(), Some(OsStr::new("lib.rs")));
        assert_eq!(path.extension(), Some(OsStr::new("rs")));
        assert!(path.is_rust_file());
    }

    #[test]
    fn test_equality_considers_crate_name() {
        let path1 = WorkspaceFilePath::new_for_test("src/lib.rs", "/workspace1", "crate1");
        let path2 = WorkspaceFilePath::new_for_test("src/lib.rs", "/workspace2", "crate1");
        let path3 = WorkspaceFilePath::new_for_test("src/lib.rs", "/workspace1", "crate2");
        let path4 = WorkspaceFilePath::new_for_test("src/main.rs", "/workspace1", "crate1");

        // Same relative path + same crate_name = equal (workspace_root ignored)
        assert_eq!(path1, path2);
        // Same relative path but different crate_name = not equal
        assert_ne!(path1, path3);
        // Different relative path = not equal
        assert_ne!(path1, path4);
    }

    #[test]
    fn test_serialization() {
        let path = WorkspaceFilePath::new_for_test("src/lib.rs", "/workspace", "my_crate");
        let json = serde_json::to_string(&path).unwrap();
        assert_eq!(json, r#"{"path":"src/lib.rs","crate_name":"my_crate"}"#);
    }

    #[test]
    fn test_deserialization_with_seed() {
        use serde::de::DeserializeSeed;

        let json = r#"{"path":"src/lib.rs","crate_name":"my_crate"}"#;
        let workspace_root = Arc::from(Path::new("/workspace"));
        let seed = WorkspaceFilePathSeed::new(workspace_root);

        let mut de = serde_json::Deserializer::from_str(json);
        let path = seed.deserialize(&mut de).unwrap();

        assert_eq!(path.as_relative(), Path::new("src/lib.rs"));
        assert_eq!(path.crate_name().as_str(), "my_crate");
        assert_eq!(path.workspace_root(), Path::new("/workspace"));
    }

    #[test]
    fn test_with_context() {
        let path = WorkspaceFilePath::new_for_test("src/lib.rs", "/old", "old_crate");
        let new_path = path.with_context(
            Arc::from(Path::new("/new")),
            CrateName::new_for_test("new_crate"),
        );
        assert_eq!(new_path.workspace_root(), Path::new("/new"));
        assert_eq!(new_path.crate_name().as_str(), "new_crate");
    }

    #[test]
    fn test_write_creates_parent_directories() {
        use tempfile::tempdir;

        let temp = tempdir().unwrap();
        let workspace_root = temp.path();

        // Create a path with nested directories that don't exist
        let path = WorkspaceFilePath::new_for_test(
            "src/deep/nested/module/lib.rs",
            workspace_root.to_str().unwrap(),
            "test_crate",
        );

        // Parent directories don't exist yet
        assert!(!path.to_absolute().parent().unwrap().exists());

        // Write should succeed and create all parent directories
        path.write("// test content").unwrap();

        // Verify file exists and has correct content
        assert!(path.exists());
        assert_eq!(path.read().unwrap(), "// test content");
    }

    #[test]
    fn test_write_with_parents_utility() {
        use tempfile::tempdir;

        let temp = tempdir().unwrap();
        let file_path = temp.path().join("a/b/c/file.txt");

        // Parent directories don't exist
        assert!(!file_path.parent().unwrap().exists());

        // write_with_parents should create them
        write_with_parents(&file_path, "hello").unwrap();

        // Verify
        assert!(file_path.exists());
        assert_eq!(std::fs::read_to_string(&file_path).unwrap(), "hello");
    }
}