ryo-app 0.1.0

//! Project: In-memory collection of AST files with workspace metadata
//!
//! Provides file collection with I/O capabilities.
//! Does NOT include transformation logic (use ryo-executor).
//! Does NOT include search logic (use ryo-analysis).
//!
//! # Design
//!
//! In the Context-centric design (Phase 5), `Project` serves as an I/O adapter:
//! - Loading: `Project::load()` → files + metadata used to create `AnalysisContext`
//! - Writing: `Project::write_from_context()` → sync Context changes to disk
//!
//! The `AnalysisContext` is the Single Source of Truth for file content.
//!
//! # Workspace Detection
//!
//! `Project` uses `ryo_symbol::CargoMetadataProvider` for accurate workspace detection:
//! 1. If `ryo.toml` exists, use `manifest_path` or `workspace_root` settings
//! 2. Otherwise, detect `Cargo.toml` from the given path
//!
//! This ensures consistent workspace root detection across all components.

use crate::config::RyoConfig;
use ryo_source::pure::PureFile;
use ryo_symbol::{
    write_with_parents, CargoMetadataProvider, WorkspaceFilePath, WorkspaceMetadataProvider,
    WorkspacePathResolver,
};
use std::collections::HashMap;
use std::path::{Path, PathBuf};

/// Project error types
#[derive(Debug, thiserror::Error)]
pub enum ProjectError {
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    #[error("Parse error in {path}: {message}")]
    Parse { path: PathBuf, message: String },

    #[error("File not found: {0}")]
    FileNotFound(PathBuf),

    #[error("Cargo metadata error: {0}")]
    Metadata(#[from] ryo_symbol::MetadataError),

    #[error("Config error: {0}")]
    Config(#[from] crate::config::ConfigError),

    #[error("Source generation failed: {0}")]
    SourceGeneration(#[from] ryo_source::pure::ToSynError),
}

/// A project loaded entirely in memory as PureFile ASTs.
///
/// This is a pure data container with I/O capabilities.
/// For transformations, use `ryo-executor::Workspace`.
/// For searching, use `ryo-analysis::DiscoveryEngine`.
///
/// # Fields
///
/// - `config_root`: Location of `ryo.toml` (or where it would be)
/// - `metadata`: Cargo workspace metadata (crate info, paths)
/// - `config`: Project configuration from `ryo.toml`
/// - `files`: Loaded source files
pub struct Project {
    /// Location of ryo.toml (or the directory passed to load)
    config_root: PathBuf,

    /// Cargo metadata provider (workspace info from cargo metadata)
    metadata: CargoMetadataProvider,

    /// Project configuration (from ryo.toml)
    config: RyoConfig,

    /// Files loaded as PureFile ASTs (keyed by absolute PathBuf for backward compat)
    files: HashMap<PathBuf, PureFile>,
}

impl Project {
    /// Load a project from disk
    ///
    /// # Workflow
    ///
    /// 1. Look for `ryo.toml` in the given directory
    /// 2. Determine Cargo.toml location from config or auto-detect
    /// 3. Create `CargoMetadataProvider` for workspace info
    /// 4. Load files by traversing mod declarations from entry points
    ///
    /// # Arguments
    ///
    /// * `path` - Directory containing the project (with or without ryo.toml)
    pub fn load(path: impl AsRef<Path>) -> Result<Self, ProjectError> {
        let config_root = path.as_ref().canonicalize()?;

        // 1. Load ryo.toml (or use default)
        let config = RyoConfig::load_or_default(&config_root);

        // 2. Determine manifest path
        let manifest_path = Self::resolve_manifest_path(&config_root, &config);

        // 3. Create CargoMetadataProvider
        let metadata = CargoMetadataProvider::from_manifest(&manifest_path)?;

        // 4. Load files by traversing mod declarations from entry points
        let mut files = HashMap::new();
        let workspace_root = metadata.workspace_root();
        for member in metadata.members() {
            Self::load_from_entry_points(workspace_root, member, &mut files)?;
        }

        Ok(Self {
            config_root,
            metadata,
            config,
            files,
        })
    }

    /// Resolve the Cargo.toml manifest path
    fn resolve_manifest_path(config_root: &Path, config: &RyoConfig) -> PathBuf {
        // Priority:
        // 1. Explicit manifest_path in config
        // 2. workspace_root + Cargo.toml
        // 3. config_root + Cargo.toml (no upward search if exists)
        // 4. Search upward for Cargo.toml (only if not found in config_root)

        if let Some(ref manifest) = config.project.manifest_path {
            return config_root.join(manifest);
        }

        if let Some(ref ws_root) = config.project.workspace_root {
            return config_root.join(ws_root).join("Cargo.toml");
        }

        // Check config_root first - if it exists, use it directly
        let default_manifest = config_root.join("Cargo.toml");
        if default_manifest.exists() {
            return default_manifest;
        }

        // Only search upward if not found in config_root
        config_root
            .ancestors()
            .skip(1) // Skip config_root itself (already checked)
            .find(|p| p.join("Cargo.toml").exists())
            .map(|p| p.join("Cargo.toml"))
            .unwrap_or(default_manifest)
    }

    /// Get the config root (where ryo.toml is or would be)
    pub fn config_root(&self) -> &Path {
        &self.config_root
    }

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

    /// Get the root path (alias for workspace_root for backward compatibility)
    pub fn root(&self) -> &Path {
        self.workspace_root()
    }

    /// Get the Cargo metadata provider
    pub fn metadata(&self) -> &CargoMetadataProvider {
        &self.metadata
    }

    /// Get the project configuration
    pub fn config(&self) -> &RyoConfig {
        &self.config
    }

    /// Create a WorkspacePathResolver for this project
    ///
    /// Uses workspace type from CargoMetadataProvider to correctly validate
    /// `crate::` paths (ambiguous in multi-crate workspaces).
    pub fn path_resolver(&self) -> WorkspacePathResolver {
        WorkspacePathResolver::with_type(
            self.workspace_root().to_path_buf(),
            self.metadata.workspace_type(),
        )
    }

    /// Get all file paths
    pub fn file_paths(&self) -> impl Iterator<Item = &PathBuf> {
        self.files.keys()
    }

    /// Get all files
    pub fn files(&self) -> &HashMap<PathBuf, PureFile> {
        &self.files
    }

    /// Get mutable access to files
    pub fn files_mut(&mut self) -> &mut HashMap<PathBuf, PureFile> {
        &mut self.files
    }

    /// Number of files loaded
    pub fn file_count(&self) -> usize {
        self.files.len()
    }

    /// Resolve a path to the actual key in the files HashMap.
    /// Handles both relative and absolute paths.
    pub fn resolve_path(&self, path: &Path) -> Option<PathBuf> {
        // Try exact match first
        if self.files.contains_key(path) {
            return Some(path.to_path_buf());
        }

        // If relative path, try joining with root
        if path.is_relative() {
            let absolute = self.root().join(path);
            if self.files.contains_key(&absolute) {
                return Some(absolute);
            }
        }

        // If absolute path, try canonicalizing (handles symlinks like /var -> /private/var)
        if path.is_absolute() {
            if let Ok(canonical) = path.canonicalize() {
                if self.files.contains_key(&canonical) {
                    return Some(canonical);
                }
            }
            // Also try stripping root to get relative
            if let Ok(relative) = path.strip_prefix(self.root()) {
                let relative_buf = relative.to_path_buf();
                if self.files.contains_key(&relative_buf) {
                    return Some(relative_buf);
                }
            }
        }

        None
    }

    /// Get a file by path
    pub fn get_file(&self, path: &Path) -> Option<&PureFile> {
        self.resolve_path(path)
            .and_then(|resolved| self.files.get(&resolved))
    }

    /// Get a mutable file by path
    pub fn get_file_mut(&mut self, path: &Path) -> Option<&mut PureFile> {
        if let Some(resolved) = self.resolve_path(path) {
            self.files.get_mut(&resolved)
        } else {
            None
        }
    }

    /// Insert or update a file
    pub fn insert_file(&mut self, path: PathBuf, file: PureFile) {
        self.files.insert(path, file);
    }

    /// Get a file and its resolved path
    pub fn get_file_with_path(&self, path: &Path) -> Option<(PathBuf, &PureFile)> {
        self.resolve_path(path)
            .and_then(|resolved| self.files.get(&resolved).map(|f| (resolved, f)))
    }

    /// Get a mutable file and its resolved path
    pub fn get_file_mut_with_path(&mut self, path: &Path) -> Option<(PathBuf, &mut PureFile)> {
        if let Some(resolved) = self.resolve_path(path) {
            self.files.get_mut(&resolved).map(|f| (resolved, f))
        } else {
            None
        }
    }

    /// Check if a file exists
    pub fn contains_file(&self, path: &Path) -> bool {
        self.resolve_path(path).is_some()
    }

    /// Get generated source for a file
    pub fn get_source(&self, path: &Path) -> Result<Option<String>, ProjectError> {
        Ok(self.get_file(path).map(|f| f.to_source()).transpose()?)
    }

    /// Write modified files back to disk
    ///
    /// Creates parent directories if they don't exist (for newly created files).
    pub fn write_to_disk(&self, paths: &[PathBuf]) -> Result<usize, ProjectError> {
        let mut written = 0;

        for path in paths {
            if let Some(file) = self.files.get(path) {
                let source = file.to_source()?;
                write_with_parents(path, &source)?;
                written += 1;
            }
        }

        Ok(written)
    }

    /// Write all files to disk
    pub fn write_all_to_disk(&self) -> Result<usize, ProjectError> {
        let paths: Vec<_> = self.files.keys().cloned().collect();
        self.write_to_disk(&paths)
    }

    // ========================================================================
    // Context-Centric I/O (Phase 5)
    // ========================================================================

    /// Load files from a project directory without creating a Project instance.
    ///
    /// This is the preferred method for the Context-centric design where
    /// `AnalysisContext` is the Single Source of Truth for file content.
    ///
    /// # Example
    ///
    /// ```ignore
    /// let files = Project::load_files("/path/to/project")?;
    /// let context = AnalysisContext::from_path_files(files, "crate");
    /// ```
    pub fn load_files(root: impl AsRef<Path>) -> Result<HashMap<PathBuf, PureFile>, ProjectError> {
        let root = root.as_ref().canonicalize()?;
        let mut files = HashMap::new();

        Self::load_dir(&root, &root, &mut files)?;

        Ok(files)
    }

    /// Write modified files from an AnalysisContext to disk.
    ///
    /// # Arguments
    ///
    /// * `ctx` - The AnalysisContext containing the modified files
    /// * `files` - The WorkspaceFilePaths of the files to write
    ///
    /// # Returns
    ///
    /// The number of files successfully written to disk.
    pub fn write_from_context(
        &self,
        ctx: &ryo_analysis::AnalysisContext,
        files: &[WorkspaceFilePath],
    ) -> Result<usize, ProjectError> {
        let mut written = 0;

        for file_path in files {
            if let Some(file) = ctx.file(file_path) {
                let source = file.to_source()?;
                // Use WorkspaceFilePath::write() to ensure parent dirs are created
                file_path.write(&source)?;
                written += 1;
            }
        }

        Ok(written)
    }

    /// Sync modified files from Context back to Project.files.
    ///
    /// Maintains backward compatibility for code that still reads from Project.files.
    pub fn sync_from_context(
        &mut self,
        ctx: &ryo_analysis::AnalysisContext,
        files: &[WorkspaceFilePath],
    ) {
        for file_path in files {
            if let Some(file) = ctx.file(file_path) {
                let absolute_path = file_path.to_absolute();
                self.files.insert(absolute_path, (*file).clone());
            }
        }
    }

    // ========================================================================
    // Private helpers
    // ========================================================================

    /// Load files from a crate's entry points by traversing mod declarations
    fn load_from_entry_points(
        workspace_root: &Path,
        crate_info: &ryo_symbol::CrateInfo,
        files: &mut HashMap<PathBuf, PureFile>,
    ) -> Result<(), ProjectError> {
        use ryo_symbol::TargetKind;

        for target in &crate_info.entry_points {
            // Only process lib and bin targets (skip tests, examples, benches)
            if !matches!(target.kind, TargetKind::Lib | TargetKind::Bin) {
                continue;
            }

            // target.src_path is relative to workspace_root
            let entry_path = workspace_root.join(target.src_path.as_str());
            if entry_path.exists() {
                Self::load_module_tree(&entry_path, files)?;
            }
        }

        Ok(())
    }

    /// Recursively load a module and all its child modules
    fn load_module_tree(
        file_path: &Path,
        files: &mut HashMap<PathBuf, PureFile>,
    ) -> Result<(), ProjectError> {
        // Skip if already loaded
        if files.contains_key(file_path) {
            return Ok(());
        }

        // Try to canonicalize for consistent keys
        let canonical_path = file_path
            .canonicalize()
            .unwrap_or_else(|_| file_path.to_path_buf());

        if files.contains_key(&canonical_path) {
            return Ok(());
        }

        // Load and parse the file
        let pure_file = match Self::load_file(file_path) {
            Ok(f) => f,
            Err(e) => {
                tracing::warn!("Failed to load {}: {}", file_path.display(), e);
                return Ok(());
            }
        };

        // Extract mod declarations before inserting
        let mod_names: Vec<String> = pure_file
            .items
            .iter()
            .filter_map(|item| {
                if let ryo_source::pure::PureItem::Mod(m) = item {
                    // Only external mod declarations (mod foo;)
                    if m.items.is_empty() {
                        return Some(m.name.clone());
                    }
                }
                None
            })
            .collect();

        // Insert the file
        files.insert(canonical_path.clone(), pure_file);

        // Get the directory for child modules.
        // For Rust 2018 style (src/foo.rs), child modules are in src/foo/
        // For classic style (src/foo/mod.rs), child modules are in src/foo/
        let parent_dir = canonical_path
            .parent()
            .ok_or_else(|| ProjectError::FileNotFound(file_path.to_path_buf()))?;

        // Determine the search directory for child modules
        let child_search_dir = if let Some(file_stem) = canonical_path.file_stem() {
            let file_name = canonical_path.file_name().and_then(|n| n.to_str());
            if file_name != Some("mod.rs")
                && file_name != Some("lib.rs")
                && file_name != Some("main.rs")
            {
                // Rust 2018 style: src/foo.rs -> child modules in src/foo/
                parent_dir.join(file_stem)
            } else {
                // Classic style: src/foo/mod.rs -> child modules in src/foo/
                parent_dir.to_path_buf()
            }
        } else {
            parent_dir.to_path_buf()
        };

        // Resolve and load child modules
        for mod_name in mod_names {
            if let Some(child_path) = Self::resolve_mod_path(&child_search_dir, &mod_name) {
                Self::load_module_tree(&child_path, files)?;
            }
        }

        Ok(())
    }

    /// Resolve a module name to its file path
    ///
    /// Follows Rust's module resolution rules:
    /// - `mod foo;` in `src/lib.rs` → `src/foo.rs` or `src/foo/mod.rs`
    /// - `mod bar;` in `src/foo/mod.rs` → `src/foo/bar.rs` or `src/foo/bar/mod.rs`
    fn resolve_mod_path(parent_dir: &Path, mod_name: &str) -> Option<PathBuf> {
        // Try modern style: parent/mod_name.rs
        let modern_path = parent_dir.join(format!("{}.rs", mod_name));
        if modern_path.exists() {
            return Some(modern_path);
        }

        // Try classic style: parent/mod_name/mod.rs
        let classic_path = parent_dir.join(mod_name).join("mod.rs");
        if classic_path.exists() {
            return Some(classic_path);
        }

        // Module file not found (could be in #[path = "..."] attribute)
        tracing::debug!(
            "Module '{}' not found in {} (tried {} and {})",
            mod_name,
            parent_dir.display(),
            modern_path.display(),
            classic_path.display()
        );
        None
    }

    #[allow(dead_code)]
    fn load_dir(
        _root: &Path,
        dir: &Path,
        files: &mut HashMap<PathBuf, PureFile>,
    ) -> Result<(), ProjectError> {
        if !dir.is_dir() {
            return Ok(());
        }

        let dir_name = dir.file_name().and_then(|n| n.to_str()).unwrap_or("");
        if matches!(
            dir_name,
            "target" | "node_modules" | ".git" | "dist" | "build"
        ) {
            return Ok(());
        }

        for entry in std::fs::read_dir(dir)? {
            let entry = entry?;
            let path = entry.path();

            if path.is_dir() {
                Self::load_dir(_root, &path, files)?;
            } else if path.extension().map(|e| e == "rs").unwrap_or(false) {
                match Self::load_file(&path) {
                    Ok(pure) => {
                        files.insert(path, pure);
                    }
                    Err(e) => {
                        tracing::warn!("Failed to parse {}: {}", path.display(), e);
                    }
                }
            }
        }

        Ok(())
    }

    fn load_file(path: &Path) -> Result<PureFile, ProjectError> {
        let content = std::fs::read_to_string(path)?;
        PureFile::from_source(&content).map_err(|e| ProjectError::Parse {
            path: path.to_path_buf(),
            message: e.to_string(),
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::fs;
    use tempfile::tempdir;

    fn create_test_project() -> tempfile::TempDir {
        let dir = tempdir().unwrap();
        let src = dir.path().join("src");
        fs::create_dir(&src).unwrap();

        // Create Cargo.toml (required for CargoMetadataProvider)
        fs::write(
            dir.path().join("Cargo.toml"),
            r#"[package]
name = "test-project"
version = "0.1.0"
edition = "2021"
"#,
        )
        .unwrap();

        fs::write(
            src.join("lib.rs"),
            r#"
pub fn hello() -> &'static str {
    "Hello, World!"
}
"#,
        )
        .unwrap();

        fs::write(
            src.join("main.rs"),
            r#"
fn main() {
    println!("{}", hello());
}
"#,
        )
        .unwrap();

        dir
    }

    #[test]
    fn test_load_project() {
        let dir = create_test_project();
        let project = Project::load(dir.path()).unwrap();

        // Project successfully loaded
        assert!(
            project.file_count() >= 1,
            "Expected at least 1 file, got {}",
            project.file_count()
        );
        assert!(project.workspace_root().exists());

        // Verify lib.rs is present (bin targets may not be loaded depending on cargo metadata)
        let lib_exists = project.file_paths().any(|p| p.ends_with("lib.rs"));
        assert!(lib_exists, "lib.rs not found in project");
    }

    #[test]
    fn test_get_file() {
        let dir = create_test_project();
        let project = Project::load(dir.path()).unwrap();

        // Use canonicalized path to handle macOS /var -> /private/var symlink
        let lib_path = dir.path().canonicalize().unwrap().join("src/lib.rs");
        assert!(project.get_file(&lib_path).is_some());
    }

    #[test]
    fn test_resolve_relative_path() {
        let dir = create_test_project();
        let project = Project::load(dir.path()).unwrap();

        // Should resolve relative path
        let relative = PathBuf::from("src/lib.rs");
        let resolved = project.resolve_path(&relative);
        assert!(resolved.is_some(), "Failed to resolve src/lib.rs");

        // Verify the resolved path exists in files
        if let Some(resolved_path) = resolved {
            assert!(
                project.files().contains_key(&resolved_path),
                "Resolved path not in files: {:?}",
                resolved_path
            );
        }
    }

    #[test]
    fn test_metadata_provider() {
        let dir = create_test_project();
        let project = Project::load(dir.path()).unwrap();

        // Check that metadata provider is available
        let metadata = project.metadata();
        assert_eq!(metadata.workspace_root(), project.workspace_root());

        // Check crate info
        let crates = metadata.all_crates();
        assert!(!crates.is_empty());
    }

    #[test]
    fn test_path_resolver() {
        let dir = create_test_project();
        let project = Project::load(dir.path()).unwrap();

        // Check that path resolver works
        let resolver = project.path_resolver();
        // Use canonicalized path to handle macOS /var -> /private/var symlink
        let absolute_path = dir.path().canonicalize().unwrap().join("src/lib.rs");
        let result = resolver.resolve(&absolute_path);
        assert!(result.is_ok());
    }

    #[test]
    fn test_load_files_static() {
        // Test that load_files() returns files without creating a Project instance
        let dir = create_test_project();
        let files = Project::load_files(dir.path()).unwrap();

        assert_eq!(files.len(), 2);
        assert!(files
            .values()
            .any(|f| f.to_source().unwrap().contains("hello")));
    }

    // Note: Context integration tests removed - they depend on old FileId-based API.
    // New tests should use WorkspaceFilePath-based API with AnalysisContext.files().
}