use std::path::PathBuf;

use crate::config::TargetConfig;
use crate::error::{EmpveError, Result};

/// Manages all paths used by empeve following XDG conventions
#[derive(Debug, Clone)]
pub struct Paths {
    /// Base config directory (~/.config/empeve)
    pub config_dir: PathBuf,

    /// Config file path (~/.config/empeve/config.toml)
    pub config_file: PathBuf,

    /// Directory for cloned repos (~/.config/empeve/repos)
    pub repos_dir: PathBuf,

    /// Directory for external catalog TOML files (~/.config/empeve/catalogs)
    pub catalogs_dir: PathBuf,

    /// mpv scripts directory (~/.config/mpv/scripts)
    pub mpv_scripts_dir: PathBuf,

    /// mpv script-opts directory (~/.config/mpv/script-opts)
    pub mpv_script_opts_dir: PathBuf,

    /// mpv fonts directory (~/.config/mpv/fonts)
    pub mpv_fonts_dir: PathBuf,

    /// mpv shaders directory (~/.config/mpv/shaders)
    pub mpv_shaders_dir: PathBuf,

    /// Lockfile path (~/.config/empeve/empeve.lock)
    pub lockfile: PathBuf,
}

impl Paths {
    /// Create a new Paths instance using XDG conventions
    pub fn new() -> Result<Self> {
        let config_base = dirs::config_dir()
            .ok_or_else(|| EmpveError::Config("Could not determine config directory".into()))?;

        let config_dir = config_base.join("empeve");
        let mpv_dir = config_base.join("mpv");

        Ok(Self {
            config_file: config_dir.join("config.toml"),
            repos_dir: config_dir.join("repos"),
            catalogs_dir: config_dir.join("catalogs"),
            lockfile: config_dir.join("empeve.lock"),
            config_dir,
            mpv_scripts_dir: mpv_dir.join("scripts"),
            mpv_script_opts_dir: mpv_dir.join("script-opts"),
            mpv_fonts_dir: mpv_dir.join("fonts"),
            mpv_shaders_dir: mpv_dir.join("shaders"),
        })
    }

    /// Create a Paths instance with a custom config file path
    pub fn with_config_file(config_file: PathBuf) -> Result<Self> {
        let mut paths = Self::new()?;
        paths.config_file = config_file;
        Ok(paths)
    }

    /// Ensure all required directories exist
    pub fn ensure_directories(&self) -> Result<()> {
        std::fs::create_dir_all(&self.config_dir)?;
        std::fs::create_dir_all(&self.repos_dir)?;
        std::fs::create_dir_all(&self.mpv_scripts_dir)?;
        Ok(())
    }

    /// Get the local path for a repository based on its identifier
    pub fn repo_path(&self, identifier: &str) -> PathBuf {
        let sanitized_name = sanitize_repo_name(identifier);
        self.repos_dir.join(sanitized_name)
    }
}

impl Default for Paths {
    fn default() -> Self {
        Self::new().expect("Failed to determine config paths")
    }
}

/// Sanitize a repository identifier for use as a directory name
fn sanitize_repo_name(identifier: &str) -> String {
    identifier
        .trim_start_matches("https://")
        .trim_start_matches("http://")
        .trim_start_matches("git@")
        .replace("github.com/", "")
        .replace("github.com:", "")
        .replace(".git", "")
        .replace('/', "_")
        .replace(':', "_")
}

/// Known mpv configuration locations to auto-detect
const KNOWN_MPV_CONFIGS: &[(&str, &str)] = &[
    ("mpv", "mpv"),
    ("jellyfin-mpv-shim", "jellyfin-mpv-shim"),
    ("celluloid", "celluloid"),
    ("gnome-mpv", "gnome-mpv"),
];

/// Flatpak mpv config locations
const FLATPAK_MPV_CONFIGS: &[(&str, &str)] = &[
    ("mpv-flatpak", ".var/app/io.mpv.Mpv/config/mpv"),
];

/// Detected mpv config folder
#[derive(Debug, Clone)]
pub struct DetectedTarget {
    /// Display name for the target
    pub name: String,
    /// Path to the config folder
    pub path: PathBuf,
    /// Whether this folder has existing scripts
    pub has_scripts: bool,
    /// Number of existing scripts found
    pub script_count: usize,
}

impl DetectedTarget {
    /// Convert to a TargetConfig
    pub fn to_target_config(&self) -> TargetConfig {
        TargetConfig::new(&self.name, &self.path)
    }
}

/// Detect all mpv configuration folders on the system
pub fn detect_mpv_configs() -> Vec<DetectedTarget> {
    let mut targets = Vec::new();

    // Get config base directory
    let config_base = match dirs::config_dir() {
        Some(dir) => dir,
        None => return targets,
    };

    // Check known XDG config locations
    for (name, subdir) in KNOWN_MPV_CONFIGS {
        let path = config_base.join(subdir);
        if path.exists() && path.is_dir() {
            let (has_scripts, script_count) = check_scripts_dir(&path);
            targets.push(DetectedTarget {
                name: name.to_string(),
                path,
                has_scripts,
                script_count,
            });
        }
    }

    // Check Flatpak locations
    if let Some(home) = dirs::home_dir() {
        for (name, subdir) in FLATPAK_MPV_CONFIGS {
            let path = home.join(subdir);
            if path.exists() && path.is_dir() {
                let (has_scripts, script_count) = check_scripts_dir(&path);
                targets.push(DetectedTarget {
                    name: name.to_string(),
                    path,
                    has_scripts,
                    script_count,
                });
            }
        }
    }

    targets
}

/// Check if a mpv config folder has a scripts directory with scripts
fn check_scripts_dir(mpv_path: &PathBuf) -> (bool, usize) {
    let scripts_dir = mpv_path.join("scripts");
    if !scripts_dir.exists() || !scripts_dir.is_dir() {
        return (false, 0);
    }

    let count = std::fs::read_dir(&scripts_dir)
        .map(|entries| {
            entries
                .filter_map(|e| e.ok())
                .filter(|e| {
                    let name = e.file_name().to_string_lossy().to_string();
                    !name.starts_with('.') && (name.ends_with(".lua") || name.ends_with(".js") || e.path().is_dir())
                })
                .count()
        })
        .unwrap_or(0);

    (count > 0, count)
}

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

    #[test]
    fn test_sanitize_repo_name() {
        assert_eq!(sanitize_repo_name("user/repo"), "user_repo");
        assert_eq!(
            sanitize_repo_name("https://github.com/user/repo.git"),
            "user_repo"
        );
        assert_eq!(
            sanitize_repo_name("git@github.com:user/repo.git"),
            "user_repo"
        );
    }
}