mcp-tools 0.1.0

//! Git Tools MCP Server
//!
//! Provides Git repository operations via MCP protocol including:
//! - Repository status and diff analysis
//! - Commit history and blame information
//! - Branch analysis and merge conflict detection
//! - Change impact analysis

use async_trait::async_trait;
use git2::{BlameOptions, DiffOptions, Repository, Status, StatusOptions};
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use tracing::{debug, error, info, warn};

use crate::common::{
    BaseServer, McpContent, McpServerBase, McpTool, McpToolRequest, McpToolResponse,
    ServerCapabilities, ServerConfig,
};
use crate::{McpToolsError, Result};

/// Git Tools MCP Server
pub struct GitToolsServer {
    base: BaseServer,
}

/// Git repository status information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GitStatus {
    pub branch: String,
    pub ahead: usize,
    pub behind: usize,
    pub modified: Vec<String>,
    pub added: Vec<String>,
    pub deleted: Vec<String>,
    pub untracked: Vec<String>,
    pub conflicted: Vec<String>,
}

/// Git commit information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CommitInfo {
    pub id: String,
    pub short_id: String,
    pub message: String,
    pub author: String,
    pub email: String,
    pub timestamp: i64,
    pub files_changed: Vec<String>,
}

/// Git diff information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DiffInfo {
    pub file_path: String,
    pub status: String,
    pub additions: usize,
    pub deletions: usize,
    pub hunks: Vec<DiffHunk>,
}

/// Git diff hunk
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DiffHunk {
    pub old_start: usize,
    pub old_lines: usize,
    pub new_start: usize,
    pub new_lines: usize,
    pub header: String,
}

/// Git blame information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BlameInfo {
    pub file_path: String,
    pub lines: Vec<BlameLine>,
}

/// Individual blame line
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BlameLine {
    pub line_number: usize,
    pub content: String,
    pub commit_id: String,
    pub author: String,
    pub timestamp: i64,
}

/// Branch information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BranchInfo {
    pub name: String,
    pub is_current: bool,
    pub is_remote: bool,
    pub last_commit: String,
    pub ahead: usize,
    pub behind: usize,
}

impl GitToolsServer {
    pub async fn new(config: ServerConfig) -> Result<Self> {
        let base = BaseServer::new(config).await?;
        Ok(Self { base })
    }

    /// Get repository instance (no caching for thread safety)
    fn get_repository(&self, repo_path: &Path) -> Result<Repository> {
        let canonical_path = repo_path
            .canonicalize()
            .map_err(|e| McpToolsError::Server(format!("Invalid repository path: {}", e)))?;

        Repository::discover(&canonical_path)
            .map_err(|e| McpToolsError::Server(format!("Git repository not found: {}", e)))
    }

    /// Get repository status
    async fn get_status(&self, repo_path: &Path) -> Result<GitStatus> {
        let repo = self.get_repository(repo_path)?;

        // Get current branch
        let head = repo
            .head()
            .map_err(|e| McpToolsError::Server(format!("Failed to get HEAD: {}", e)))?;
        let branch = head.shorthand().unwrap_or("HEAD").to_string();

        // Get ahead/behind counts (simplified implementation)
        let (ahead, behind) = (0, 0); // Would need upstream comparison for accurate counts

        // Get file statuses
        let mut status_opts = StatusOptions::new();
        status_opts.include_untracked(true);
        status_opts.include_ignored(false);

        let statuses = repo
            .statuses(Some(&mut status_opts))
            .map_err(|e| McpToolsError::Server(format!("Failed to get status: {}", e)))?;

        let mut modified = Vec::new();
        let mut added = Vec::new();
        let mut deleted = Vec::new();
        let mut untracked = Vec::new();
        let mut conflicted = Vec::new();

        for entry in statuses.iter() {
            let path = entry.path().unwrap_or("").to_string();
            let status = entry.status();

            if status.contains(Status::CONFLICTED) {
                conflicted.push(path);
            } else if status.contains(Status::WT_NEW) || status.contains(Status::INDEX_NEW) {
                added.push(path);
            } else if status.contains(Status::WT_MODIFIED)
                || status.contains(Status::INDEX_MODIFIED)
            {
                modified.push(path);
            } else if status.contains(Status::WT_DELETED) || status.contains(Status::INDEX_DELETED)
            {
                deleted.push(path);
            } else if status.contains(Status::WT_NEW) {
                untracked.push(path);
            }
        }

        Ok(GitStatus {
            branch,
            ahead,
            behind,
            modified,
            added,
            deleted,
            untracked,
            conflicted,
        })
    }

    /// Get repository diff
    async fn get_diff(
        &self,
        repo_path: &Path,
        params: &serde_json::Value,
    ) -> Result<Vec<DiffInfo>> {
        let repo = self.get_repository(repo_path)?;

        let staged = params
            .get("staged")
            .and_then(|v| v.as_str())
            .map(|s| s == "true")
            .unwrap_or(false);

        let diff = if staged {
            // Staged changes (index vs HEAD)
            let head_tree = repo.head()?.peel_to_tree()?;
            let index = repo.index()?;
            repo.diff_tree_to_index(Some(&head_tree), Some(&index), None)?
        } else {
            // Working directory changes
            repo.diff_index_to_workdir(None, None)?
        };

        let mut diff_infos = Vec::new();

        diff.foreach(
            &mut |delta, _progress| {
                if let Some(new_file) = delta.new_file().path() {
                    let file_path = new_file.to_string_lossy().to_string();
                    let status = match delta.status() {
                        git2::Delta::Added => "added",
                        git2::Delta::Deleted => "deleted",
                        git2::Delta::Modified => "modified",
                        git2::Delta::Renamed => "renamed",
                        git2::Delta::Copied => "copied",
                        _ => "unknown",
                    }
                    .to_string();

                    diff_infos.push(DiffInfo {
                        file_path,
                        status,
                        additions: 0, // Would need to parse hunks for accurate counts
                        deletions: 0,
                        hunks: Vec::new(), // Simplified for now
                    });
                }
                true
            },
            None,
            None,
            None,
        )?;

        Ok(diff_infos)
    }

    /// Get commit log
    async fn get_log(
        &self,
        repo_path: &Path,
        params: &serde_json::Value,
    ) -> Result<Vec<CommitInfo>> {
        let repo = self.get_repository(repo_path)?;

        let limit = params
            .get("limit")
            .and_then(|v| v.as_str())
            .and_then(|s| s.parse::<usize>().ok())
            .unwrap_or(10);

        let file_path = params.get("file_path").and_then(|v| v.as_str());

        let mut revwalk = repo
            .revwalk()
            .map_err(|e| McpToolsError::Server(format!("Failed to create revwalk: {}", e)))?;
        revwalk
            .push_head()
            .map_err(|e| McpToolsError::Server(format!("Failed to push HEAD: {}", e)))?;
        revwalk
            .set_sorting(git2::Sort::TIME)
            .map_err(|e| McpToolsError::Server(format!("Failed to set sorting: {}", e)))?;

        let mut commits = Vec::new();
        let mut count = 0;

        for oid in revwalk {
            if count >= limit {
                break;
            }

            let oid =
                oid.map_err(|e| McpToolsError::Server(format!("Failed to get OID: {}", e)))?;
            let commit = repo
                .find_commit(oid)
                .map_err(|e| McpToolsError::Server(format!("Failed to find commit: {}", e)))?;

            // Filter by file path if specified
            if let Some(file_path) = file_path {
                // This is simplified - would need proper path filtering
                debug!("Filtering by file path: {}", file_path);
            }

            let author = commit.author();
            let files_changed = Vec::new(); // Would need to analyze diff for accurate file list

            commits.push(CommitInfo {
                id: commit.id().to_string(),
                short_id: commit.id().to_string()[..8].to_string(),
                message: commit.message().unwrap_or("").to_string(),
                author: author.name().unwrap_or("").to_string(),
                email: author.email().unwrap_or("").to_string(),
                timestamp: author.when().seconds(),
                files_changed,
            });

            count += 1;
        }

        Ok(commits)
    }

    /// Get blame information
    async fn get_blame(&self, repo_path: &Path, params: &serde_json::Value) -> Result<BlameInfo> {
        let repo = self.get_repository(repo_path)?;
        let file_path = params
            .get("file_path")
            .and_then(|v| v.as_str())
            .ok_or_else(|| {
                McpToolsError::Server("file_path parameter required for blame".to_string())
            })?;

        let mut blame_opts = BlameOptions::new();
        let blame = repo
            .blame_file(Path::new(file_path), Some(&mut blame_opts))
            .map_err(|e| McpToolsError::Server(format!("Failed to get blame: {}", e)))?;

        // Read file content to get line content
        let full_path = repo
            .workdir()
            .ok_or_else(|| McpToolsError::Server("Bare repository not supported".to_string()))?
            .join(file_path);

        let content = std::fs::read_to_string(&full_path)
            .map_err(|e| McpToolsError::Server(format!("Failed to read file: {}", e)))?;

        let lines: Vec<&str> = content.lines().collect();
        let mut blame_lines = Vec::new();

        for (line_num, line_content) in lines.iter().enumerate() {
            if let Some(hunk) = blame.get_line(line_num + 1) {
                let commit = repo
                    .find_commit(hunk.final_commit_id())
                    .map_err(|e| McpToolsError::Server(format!("Failed to find commit: {}", e)))?;
                let author = commit.author();

                blame_lines.push(BlameLine {
                    line_number: line_num + 1,
                    content: line_content.to_string(),
                    commit_id: hunk.final_commit_id().to_string(),
                    author: author.name().unwrap_or("").to_string(),
                    timestamp: author.when().seconds(),
                });
            }
        }

        Ok(BlameInfo {
            file_path: file_path.to_string(),
            lines: blame_lines,
        })
    }

    /// Get branch information
    async fn get_branches(&self, repo_path: &Path) -> Result<Vec<BranchInfo>> {
        let repo = self.get_repository(repo_path)?;

        let branches = repo
            .branches(Some(git2::BranchType::Local))
            .map_err(|e| McpToolsError::Server(format!("Failed to get branches: {}", e)))?;
        let mut branch_infos = Vec::new();

        let current_branch = repo
            .head()
            .ok()
            .and_then(|head| head.shorthand().map(|s| s.to_string()))
            .unwrap_or_default();

        for branch_result in branches {
            let (branch, _) = branch_result
                .map_err(|e| McpToolsError::Server(format!("Failed to process branch: {}", e)))?;

            if let Some(name) = branch
                .name()
                .map_err(|e| McpToolsError::Server(format!("Failed to get branch name: {}", e)))?
            {
                let is_current = name == current_branch;
                let last_commit = if let Some(oid) = branch.get().target() {
                    oid.to_string()[..8].to_string()
                } else {
                    "unknown".to_string()
                };

                branch_infos.push(BranchInfo {
                    name: name.to_string(),
                    is_current,
                    is_remote: false,
                    last_commit,
                    ahead: 0, // Would need upstream comparison
                    behind: 0,
                });
            }
        }

        Ok(branch_infos)
    }
}

#[async_trait]
impl McpServerBase for GitToolsServer {
    async fn get_capabilities(&self) -> Result<ServerCapabilities> {
        let mut capabilities = self.base.get_capabilities().await?;

        // Add Git-specific tools
        let git_tools = vec![
            McpTool {
                name: "git_status".to_string(),
                description: "Get Git repository status including modified, added, deleted files"
                    .to_string(),
                input_schema: serde_json::json!({
                    "type": "object",
                    "properties": {
                        "repo_path": {
                            "type": "string",
                            "description": "Path to Git repository (optional, defaults to current directory)"
                        }
                    }
                }),
                category: "git".to_string(),
                requires_permission: false,
                permissions: vec![],
            },
            McpTool {
                name: "git_diff".to_string(),
                description: "Get Git diff information for repository changes".to_string(),
                input_schema: serde_json::json!({
                    "type": "object",
                    "properties": {
                        "repo_path": {
                            "type": "string",
                            "description": "Path to Git repository (optional, defaults to current directory)"
                        },
                        "staged": {
                            "type": "string",
                            "description": "Show staged changes (true/false, default: false)"
                        }
                    }
                }),
                category: "git".to_string(),
                requires_permission: false,
                permissions: vec![],
            },
            McpTool {
                name: "git_log".to_string(),
                description: "Get Git commit history".to_string(),
                input_schema: serde_json::json!({
                    "type": "object",
                    "properties": {
                        "repo_path": {
                            "type": "string",
                            "description": "Path to Git repository (optional, defaults to current directory)"
                        },
                        "limit": {
                            "type": "string",
                            "description": "Number of commits to show (default: 10)"
                        },
                        "file_path": {
                            "type": "string",
                            "description": "Filter commits by specific file path (optional)"
                        }
                    }
                }),
                category: "git".to_string(),
                requires_permission: false,
                permissions: vec![],
            },
            McpTool {
                name: "git_blame".to_string(),
                description: "Get Git blame information for a file".to_string(),
                input_schema: serde_json::json!({
                    "type": "object",
                    "properties": {
                        "repo_path": {
                            "type": "string",
                            "description": "Path to Git repository (optional, defaults to current directory)"
                        },
                        "file_path": {
                            "type": "string",
                            "description": "Path to file for blame information"
                        }
                    },
                    "required": ["file_path"]
                }),
                category: "git".to_string(),
                requires_permission: false,
                permissions: vec![],
            },
            McpTool {
                name: "git_branches".to_string(),
                description: "Get Git branch information".to_string(),
                input_schema: serde_json::json!({
                    "type": "object",
                    "properties": {
                        "repo_path": {
                            "type": "string",
                            "description": "Path to Git repository (optional, defaults to current directory)"
                        }
                    }
                }),
                category: "git".to_string(),
                requires_permission: false,
                permissions: vec![],
            },
        ];

        capabilities.tools = git_tools;
        Ok(capabilities)
    }

    async fn handle_tool_request(&self, request: McpToolRequest) -> Result<McpToolResponse> {
        info!("Handling Git tool request: {}", request.tool);

        let repo_path = request
            .arguments
            .get("repo_path")
            .and_then(|v| v.as_str())
            .map(PathBuf::from)
            .unwrap_or_else(|| std::env::current_dir().unwrap_or_else(|_| PathBuf::from(".")));

        match request.tool.as_str() {
            "git_status" => {
                debug!("Getting Git status for: {}", repo_path.display());
                let status = self.get_status(&repo_path).await?;
                let content_text = format!(
                    "Git Status for {}\n\
                    Branch: {}\n\
                    Ahead: {}, Behind: {}\n\
                    Modified: {}\n\
                    Added: {}\n\
                    Deleted: {}\n\
                    Untracked: {}\n\
                    Conflicted: {}",
                    repo_path.display(),
                    status.branch,
                    status.ahead,
                    status.behind,
                    status.modified.len(),
                    status.added.len(),
                    status.deleted.len(),
                    status.untracked.len(),
                    status.conflicted.len()
                );

                let mut metadata = HashMap::new();
                metadata.insert("git_status".to_string(), serde_json::to_value(status)?);

                Ok(McpToolResponse {
                    id: request.id,
                    content: vec![McpContent::text(content_text)],
                    is_error: false,
                    error: None,
                    metadata,
                })
            }
            "git_diff" => {
                debug!("Getting Git diff for: {}", repo_path.display());
                let diff_infos = self.get_diff(&repo_path, &request.arguments).await?;
                let content_text = format!(
                    "Git Diff for {}\n\
                    Files changed: {}",
                    repo_path.display(),
                    diff_infos.len()
                );

                let mut metadata = HashMap::new();
                metadata.insert("git_diff".to_string(), serde_json::to_value(diff_infos)?);

                Ok(McpToolResponse {
                    id: request.id,
                    content: vec![McpContent::text(content_text)],
                    is_error: false,
                    error: None,
                    metadata,
                })
            }
            "git_log" => {
                debug!("Getting Git log for: {}", repo_path.display());
                let commits = self.get_log(&repo_path, &request.arguments).await?;
                let content_text = format!(
                    "Git Log for {}\n\
                    Commits: {}",
                    repo_path.display(),
                    commits.len()
                );

                let mut metadata = HashMap::new();
                metadata.insert("git_log".to_string(), serde_json::to_value(commits)?);

                Ok(McpToolResponse {
                    id: request.id,
                    content: vec![McpContent::text(content_text)],
                    is_error: false,
                    error: None,
                    metadata,
                })
            }
            "git_blame" => {
                debug!("Getting Git blame for: {}", repo_path.display());
                let blame_info = self.get_blame(&repo_path, &request.arguments).await?;
                let content_text = format!(
                    "Git Blame for {}\n\
                    Lines: {}",
                    blame_info.file_path,
                    blame_info.lines.len()
                );

                let mut metadata = HashMap::new();
                metadata.insert("git_blame".to_string(), serde_json::to_value(blame_info)?);

                Ok(McpToolResponse {
                    id: request.id,
                    content: vec![McpContent::text(content_text)],
                    is_error: false,
                    error: None,
                    metadata,
                })
            }
            "git_branches" => {
                debug!("Getting Git branches for: {}", repo_path.display());
                let branches = self.get_branches(&repo_path).await?;
                let current = branches.iter().find(|b| b.is_current);
                let content_text = format!(
                    "Git Branches for {}\n\
                    Total: {}\n\
                    Current: {}",
                    repo_path.display(),
                    branches.len(),
                    current.map(|b| b.name.as_str()).unwrap_or("None")
                );

                let mut metadata = HashMap::new();
                metadata.insert("git_branches".to_string(), serde_json::to_value(branches)?);

                Ok(McpToolResponse {
                    id: request.id,
                    content: vec![McpContent::text(content_text)],
                    is_error: false,
                    error: None,
                    metadata,
                })
            }
            _ => {
                warn!("Unknown Git tool: {}", request.tool);
                Err(McpToolsError::Server(format!(
                    "Unknown Git tool: {}",
                    request.tool
                )))
            }
        }
    }

    async fn get_stats(&self) -> Result<crate::common::ServerStats> {
        self.base.get_stats().await
    }

    async fn initialize(&mut self) -> Result<()> {
        info!("Initializing Git Tools MCP Server");
        Ok(())
    }

    async fn shutdown(&mut self) -> Result<()> {
        info!("Shutting down Git Tools MCP Server");
        Ok(())
    }
}