whi 0.8.1

use std::fs;
use std::io::Write;
use std::path::Path;
use std::time::{SystemTime, UNIX_EPOCH};

use crate::io::atomic_file::AtomicFile;
use crate::shell::detect::{Shell, get_config_file_path, get_saved_path_file, get_sourcing_line};

/// Save the current `PATH` for a shell
pub fn save_path(shell: &Shell, path: &str) -> Result<(), String> {
    let saved_path_file = get_saved_path_file(shell)?;

    // Create ~/.whi directory if it doesn't exist
    if let Some(parent) = saved_path_file.parent() {
        fs::create_dir_all(parent).map_err(|e| format!("Failed to create .whi directory: {e}"))?;
    }

    // Create backup if file exists
    if saved_path_file.exists() {
        let backup_path = saved_path_file.with_extension("bak");
        let mut atomic_backup = AtomicFile::new(&backup_path)
            .map_err(|e| format!("Failed to create backup file: {e}"))?;

        let existing_content = fs::read_to_string(&saved_path_file)
            .map_err(|e| format!("Failed to read existing PATH file: {e}"))?;

        atomic_backup
            .write_all(existing_content.as_bytes())
            .map_err(|e| format!("Failed to write backup: {e}"))?;

        atomic_backup
            .commit()
            .map_err(|e| format!("Failed to commit backup: {e}"))?;
    }

    // Format PATH with !path.saved directive (unified format)
    let mut formatted = String::from("!path.saved\n");
    for entry in path.split(':').filter(|s| !s.is_empty()) {
        formatted.push_str(entry);
        formatted.push('\n');
    }

    let mut atomic_file = AtomicFile::new(&saved_path_file)
        .map_err(|e| format!("Failed to create PATH file: {e}"))?;

    atomic_file
        .write_all(formatted.as_bytes())
        .map_err(|e| format!("Failed to write PATH: {e}"))?;

    atomic_file
        .commit()
        .map_err(|e| format!("Failed to commit PATH file: {e}"))?;

    // Note: We don't auto-add to config files anymore since whi init now includes saved PATH loading

    Ok(())
}

/// Ensure the whi integration line exists in the shell config file
pub fn ensure_whi_integration(shell: &Shell) -> Result<(), String> {
    let config_file = get_config_file_path(shell)?;
    let sourcing_line = get_sourcing_line(shell)?;

    // Read existing config (or empty if doesn't exist)
    let existing_content = if config_file.exists() {
        fs::read_to_string(&config_file).map_err(|e| format!("Failed to read config file: {e}"))?
    } else {
        String::new()
    };

    // Check if integration already exists
    if existing_content.contains("# whi: Load saved PATH") {
        return Ok(()); // Already integrated
    }

    // Create backup
    if config_file.exists() {
        backup_config_file(&config_file)?;
    } else {
        // Create parent directory for fish if needed
        if let Some(parent) = config_file.parent() {
            fs::create_dir_all(parent)
                .map_err(|e| format!("Failed to create config directory: {e}"))?;
        }
    }

    // Append integration line
    let new_content = if existing_content.is_empty() {
        sourcing_line
    } else if existing_content.ends_with('\n') {
        format!("{existing_content}\n{sourcing_line}")
    } else {
        format!("{existing_content}\n\n{sourcing_line}")
    };

    // Write atomically
    let mut atomic_file =
        AtomicFile::new(&config_file).map_err(|e| format!("Failed to create config file: {e}"))?;

    atomic_file
        .write_all(new_content.as_bytes())
        .map_err(|e| format!("Failed to write config: {e}"))?;

    atomic_file
        .commit()
        .map_err(|e| format!("Failed to commit config file: {e}"))?;

    Ok(())
}

/// Create a backup of a config file with timestamp
fn backup_config_file(path: &Path) -> Result<(), String> {
    let timestamp = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map_err(|e| format!("Failed to get timestamp: {e}"))?
        .as_secs();

    let backup_path = path.with_extension(format!("backup-{timestamp}"));

    fs::copy(path, &backup_path).map_err(|e| format!("Failed to create backup: {e}"))?;

    Ok(())
}

fn get_profiles_dir() -> Result<std::path::PathBuf, String> {
    let home = std::env::var("HOME").map_err(|_| "HOME environment variable not set")?;
    let profiles_dir = std::path::PathBuf::from(home).join(".whi").join("profiles");

    if !profiles_dir.exists() {
        fs::create_dir_all(&profiles_dir)
            .map_err(|e| format!("Failed to create profiles directory: {e}"))?;
    }

    Ok(profiles_dir)
}

pub fn save_profile(profile_name: &str, path: &str) -> Result<(), String> {
    use crate::path::file::format_path_file;

    if profile_name.is_empty() {
        return Err("Profile name cannot be empty".to_string());
    }

    if profile_name.contains('/') || profile_name.contains('\\') || profile_name.starts_with('.') {
        return Err(
            "Invalid profile name (cannot contain path separators or start with '.')".to_string(),
        );
    }

    let profiles_dir = get_profiles_dir()?;
    let profile_file = profiles_dir.join(profile_name);

    // Format PATH as human-friendly file
    let formatted = format_path_file(path);

    let mut atomic_file = AtomicFile::new(&profile_file)
        .map_err(|e| format!("Failed to create profile file: {e}"))?;

    atomic_file
        .write_all(formatted.as_bytes())
        .map_err(|e| format!("Failed to write profile: {e}"))?;

    atomic_file
        .commit()
        .map_err(|e| format!("Failed to commit profile file: {e}"))?;

    Ok(())
}

pub fn load_profile(profile_name: &str) -> Result<crate::path::file::ParsedPathFile, String> {
    use crate::path::file::parse_path_file;

    if profile_name.is_empty() {
        return Err("Profile name cannot be empty".to_string());
    }

    if profile_name.contains('/') || profile_name.contains('\\') || profile_name.starts_with('.') {
        return Err(
            "Invalid profile name (cannot contain path separators or start with '.')".to_string(),
        );
    }

    let profiles_dir = get_profiles_dir()?;
    let profile_file = profiles_dir.join(profile_name);

    if !profile_file.exists() {
        return Err(format!("Profile '{profile_name}' not found"));
    }

    let content = fs::read_to_string(&profile_file)
        .map_err(|e| format!("Failed to read profile file: {e}"))?;

    parse_path_file(&content)
}

pub fn delete_profile(profile_name: &str) -> Result<(), String> {
    if profile_name.is_empty() {
        return Err("Profile name cannot be empty".to_string());
    }

    if profile_name.contains('/') || profile_name.contains('\\') || profile_name.starts_with('.') {
        return Err(
            "Invalid profile name (cannot contain path separators or start with '.')".to_string(),
        );
    }

    let profiles_dir = get_profiles_dir()?;
    let profile_file = profiles_dir.join(profile_name);

    if !profile_file.exists() {
        return Err(format!("Profile '{profile_name}' not found"));
    }

    fs::remove_file(&profile_file).map_err(|e| format!("Failed to delete profile: {e}"))?;

    Ok(())
}

pub fn list_profiles() -> Result<Vec<String>, String> {
    let profiles_dir = get_profiles_dir()?;

    if !profiles_dir.exists() {
        return Ok(Vec::new());
    }

    let entries = fs::read_dir(&profiles_dir)
        .map_err(|e| format!("Failed to read profiles directory: {e}"))?;

    let mut profiles = Vec::new();

    for entry in entries.flatten() {
        if let Ok(file_type) = entry.file_type()
            && file_type.is_file()
            && let Some(name) = entry.file_name().to_str()
            && !name.starts_with('.')
        {
            profiles.push(name.to_string());
        }
    }

    profiles.sort();
    Ok(profiles)
}

/// Load saved `PATH` for a shell (used by shell integration on startup)
pub fn load_saved_path_for_shell(shell: &Shell) -> Result<String, String> {
    use crate::path::file::{apply_path_sections, parse_path_file};

    let saved_path_file = get_saved_path_file(shell)?;

    if !saved_path_file.exists() {
        return Err(format!("No saved PATH found for {}", shell.as_str()));
    }

    let content = fs::read_to_string(&saved_path_file)
        .map_err(|e| format!("Failed to read saved PATH file: {e}"))?;

    let parsed = parse_path_file(&content)?;

    apply_path_sections("", &parsed.path)
}