//! Hook manager for GitKS.
//!
//! Manages the installation, listing, and removal of git hooks
//! for bare repositories. Supports server hooks, custom hooks,
//! and gRPC callback hooks.

use std::path::{Path, PathBuf};
use std::time::Duration;

use crate::error::{GitError, GitResult};
use crate::hooks::runner::{HookResult, generate_hook_runner_script, run_hook_dir};
use crate::hooks::sanitize::{validate_hook_content, validate_hook_name};

/// Manages git hooks across repositories.
#[derive(Debug, Clone)]
pub struct HookManager {
    repo_prefix: PathBuf,
    server_hooks_dir: Option<PathBuf>,
    hook_callback_addr: Option<String>,
    hook_timeout: Duration,
    allow_custom_hooks: bool,
}

impl HookManager {
    pub fn new(
        repo_prefix: PathBuf,
        server_hooks_dir: Option<PathBuf>,
        hook_callback_addr: Option<String>,
        hook_timeout: Duration,
        allow_custom_hooks: bool,
    ) -> Self {
        Self {
            repo_prefix,
            server_hooks_dir,
            hook_callback_addr,
            hook_timeout,
            allow_custom_hooks,
        }
    }

    /// Install gitks hook runner scripts into a repository's hooks directory.
    /// Called during repository initialization.
    pub fn install_hooks(&self, repo_path: &Path) -> GitResult<()> {
        let hooks_dir = repo_path.join("hooks");
        std::fs::create_dir_all(&hooks_dir).map_err(GitError::Io)?;

        let relative_path = repo_path
            .strip_prefix(&self.repo_prefix)
            .unwrap_or(repo_path)
            .to_string_lossy()
            .trim_start_matches('/')
            .to_string();

        let server_hooks_dir_str = self
            .server_hooks_dir
            .as_ref()
            .map(|p| p.to_string_lossy().into_owned());
        let callback_addr_str = self.hook_callback_addr.clone();

        for hook_type in &["pre-receive", "update", "post-receive"] {
            let script_content = generate_hook_runner_script(
                hook_type,
                &relative_path,
                server_hooks_dir_str.as_deref(),
                callback_addr_str.as_deref(),
                self.hook_timeout.as_secs(),
            );
            let hook_path = hooks_dir.join(hook_type);
            std::fs::write(&hook_path, script_content).map_err(GitError::Io)?;
            #[cfg(unix)]
            {
                use std::os::unix::fs::PermissionsExt;
                let mut perms = std::fs::metadata(&hook_path)
                    .map_err(GitError::Io)?
                    .permissions();
                perms.set_mode(0o755);
                std::fs::set_permissions(&hook_path, perms).map_err(GitError::Io)?;
            }
            tracing::debug!(
                hook_type = %hook_type,
                path = %hook_path.display(),
                "installed gitks hook runner"
            );
        }

        tracing::info!(
            path = %repo_path.display(),
            "hooks installed for repository"
        );
        Ok(())
    }

    /// Set a custom hook script for a repository.
    pub fn set_custom_hook(
        &self,
        repo_path: &Path,
        hook_name: &str,
        content: &str,
    ) -> GitResult<()> {
        validate_hook_name(hook_name)?;
        if !self.allow_custom_hooks {
            return Err(GitError::PermissionDenied(
                "custom hooks are not allowed on this server".into(),
            ));
        }
        validate_hook_content(content)?;

        let custom_hooks_dir = repo_path.join("custom_hooks").join(hook_name).join("d");
        std::fs::create_dir_all(&custom_hooks_dir).map_err(GitError::Io)?;

        let script_name = format!("gitks_custom_{}", hook_name.replace('-', "_"));
        let script_path = custom_hooks_dir.join(&script_name);
        std::fs::write(&script_path, content).map_err(GitError::Io)?;

        #[cfg(unix)]
        {
            use std::os::unix::fs::PermissionsExt;
            let mut perms = std::fs::metadata(&script_path)
                .map_err(GitError::Io)?
                .permissions();
            perms.set_mode(0o755);
            std::fs::set_permissions(&script_path, perms).map_err(GitError::Io)?;
        }

        tracing::info!(
            repo = %repo_path.display(),
            hook_name = %hook_name,
            "custom hook set"
        );
        Ok(())
    }

    /// Remove a custom hook from a repository.
    pub fn remove_custom_hook(&self, repo_path: &Path, hook_name: &str) -> GitResult<()> {
        validate_hook_name(hook_name)?;
        let custom_hooks_dir = repo_path.join("custom_hooks").join(hook_name).join("d");
        if custom_hooks_dir.exists() {
            std::fs::remove_dir_all(&custom_hooks_dir).map_err(GitError::Io)?;
            tracing::info!(
                repo = %repo_path.display(),
                hook_name = %hook_name,
                "custom hook removed"
            );
        }
        Ok(())
    }

    /// List all hooks for a repository.
    pub fn list_hooks(&self, repo_path: &Path) -> GitResult<Vec<HookInfo>> {
        let mut hooks = Vec::new();

        let hooks_dir = repo_path.join("hooks");
        if hooks_dir.exists() {
            for hook_type in &["pre-receive", "update", "post-receive"] {
                let hook_path = hooks_dir.join(hook_type);
                if hook_path.exists() {
                    hooks.push(HookInfo {
                        hook_type: hook_type.to_string(),
                        level: HookLevel::Server,
                        path: hook_path.to_string_lossy().into_owned(),
                    });
                }
            }
        }

        if self.allow_custom_hooks {
            let custom_dir = repo_path.join("custom_hooks");
            if custom_dir.exists() {
                for entry in std::fs::read_dir(&custom_dir).map_err(GitError::Io)? {
                    let entry = entry.map_err(GitError::Io)?;
                    let name = entry.file_name().to_string_lossy().into_owned();
                    if validate_hook_name(&name).is_ok() {
                        let path = entry.path();
                        let d_dir = path.join("d");
                        if d_dir.exists() {
                            let script_count =
                                std::fs::read_dir(&d_dir).map_err(GitError::Io)?.count();
                            if script_count > 0 {
                                hooks.push(HookInfo {
                                    hook_type: name,
                                    level: HookLevel::Custom,
                                    path: d_dir.to_string_lossy().into_owned(),
                                });
                            }
                        }
                    }
                }
            }
        }

        Ok(hooks)
    }

    /// Execute a hook by running server hooks then custom hooks.
    pub fn execute_hook(&self, repo_path: &Path, hook_type: &str, stdin_data: &[u8]) -> HookResult {
        if let Some(ref server_dir) = self.server_hooks_dir {
            let dir = server_dir.join(hook_type).join("d");
            let result = run_hook_dir(&dir, hook_type, stdin_data, self.hook_timeout);
            if !result.accepted {
                return result;
            }
        }

        if self.allow_custom_hooks {
            let custom_dir = repo_path.join("custom_hooks").join(hook_type).join("d");
            let result = run_hook_dir(&custom_dir, hook_type, stdin_data, self.hook_timeout);
            if !result.accepted {
                return result;
            }
        }

        HookResult::accepted()
    }
}

/// Information about a hook.
#[derive(Debug, Clone)]
pub struct HookInfo {
    pub hook_type: String,
    pub level: HookLevel,
    pub path: String,
}

/// Hook level (server vs custom).
#[derive(Debug, Clone, PartialEq)]
pub enum HookLevel {
    Server,
    Custom,
}

impl std::fmt::Display for HookLevel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            HookLevel::Server => write!(f, "server"),
            HookLevel::Custom => write!(f, "custom"),
        }
    }
}