use askama::Template;
use axum::{
    Router,
    body::Body,
    extract::{Path, State},
    http::{StatusCode, header},
    response::{Html, Redirect, Response},
    routing::{get, post},
};
use rusqlite::params;
use zip::write::FileOptions;

use crate::auth::CurrentUser;
use crate::routes::AppState;

#[derive(Template)]
#[template(path = "backups/list.html")]
struct BackupListTemplate {
    username: String,
    is_superuser: bool,
    password_change_required: bool,
    instance_name: String,
    instance_id: i64,
    backups: Vec<BackupRow>,
}

struct BackupRow {
    id: i64,
    filename: String,
    created_at: String,
}

pub fn router() -> Router<AppState> {
    Router::new()
        .route("/instances/{id}/backups", get(list_backups))
        .route("/instances/{id}/backups/create", post(create_backup))
        .route("/backups/{id}/restore", post(restore_backup))
        .route("/backups/{id}/download", get(download_backup))
}

async fn list_backups(
    State(state): State<AppState>,
    Path(instance_id): Path<i64>,
    CurrentUser(account): CurrentUser,
) -> Result<Html<String>, axum::response::Redirect> {
    let conn = state.db.conn();
    let instance_name: String = conn
        .query_row(
            "SELECT name FROM instances WHERE id = ?1",
            params![instance_id],
            |row| row.get(0),
        )
        .map_err(|_| Redirect::to("/instances"))?;

    let mut stmt = conn
        .prepare("SELECT id, filename, created_at FROM backups WHERE instance_id = ?1 ORDER BY created_at DESC")
        .map_err(|_| Redirect::to("/instances"))?;

    let backups: Vec<BackupRow> = stmt
        .query_map(params![instance_id], |row| {
            Ok(BackupRow {
                id: row.get(0)?,
                filename: row.get(1)?,
                created_at: row.get(2)?,
            })
        })
        .map_err(|_| Redirect::to("/instances"))?
        .filter_map(|r| r.ok())
        .collect();
    drop(stmt);
    drop(conn);

    let template = BackupListTemplate {
        username: account.username.clone(),
        is_superuser: account.is_superuser,
        password_change_required: account.password_change_required,
        instance_name,
        instance_id,
        backups,
    };

    Ok(Html(template.render().unwrap_or_default()))
}

async fn create_backup(
    State(state): State<AppState>,
    Path(instance_id): Path<i64>,
    CurrentUser(_user): CurrentUser,
) -> Result<Redirect, axum::response::Redirect> {
    let conn = state.db.conn();
    let instance_name: String = conn
        .query_row(
            "SELECT name FROM instances WHERE id = ?1",
            params![instance_id],
            |row| row.get(0),
        )
        .map_err(|_| Redirect::to("/instances"))?;
    drop(conn);

    let timestamp = chrono::Utc::now().format("%Y%m%d_%H%M%S");
    let filename = format!("{instance_name}_{timestamp}.zip");

    let data_dir = state
        .config
        .server_directory
        .join("instances")
        .join(&instance_name)
        .join("data");

    let backup_dir = state.config.server_directory.join("backups");
    let _ = std::fs::create_dir_all(&backup_dir);
    let backup_path = backup_dir.join(&filename);

    if let Ok(file) = std::fs::File::create(&backup_path) {
        let mut zip = zip::ZipWriter::new(file);
        let options: FileOptions<'_, ()> =
            FileOptions::default().compression_method(zip::CompressionMethod::Deflated);

        if let Ok(entries) = std::fs::read_dir(&data_dir) {
            for entry in entries.flatten() {
                let path = entry.path();
                if path.is_file() {
                    if let Some(name) = path.file_name() {
                        if let Ok(contents) = std::fs::read(&path) {
                            let _ = zip.start_file(&*name.to_string_lossy(), options);
                            let _ = std::io::Write::write_all(&mut zip, &contents);
                        }
                    }
                }
            }
        }
        let _ = zip.finish();
    }

    let conn = state.db.conn();
    conn.execute(
        "INSERT INTO backups (instance_id, filename) VALUES (?1, ?2)",
        params![instance_id, filename],
    )
    .ok();
    drop(conn);

    Ok(Redirect::to(&format!("/instances/{instance_id}/backups")))
}

async fn restore_backup(
    State(state): State<AppState>,
    Path(backup_id): Path<i64>,
    CurrentUser(_user): CurrentUser,
) -> Result<Redirect, axum::response::Redirect> {
    let conn = state.db.conn();
    let (instance_id, _filename): (i64, String) = conn
        .query_row(
            "SELECT instance_id, filename FROM backups WHERE id = ?1",
            params![backup_id],
            |row| Ok((row.get(0)?, row.get(1)?)),
        )
        .map_err(|_| Redirect::to("/instances"))?;
    drop(conn);

    Ok(Redirect::to(&format!("/instances/{instance_id}/backups")))
}

async fn download_backup(
    State(state): State<AppState>,
    Path(backup_id): Path<i64>,
    CurrentUser(_user): CurrentUser,
) -> Result<Response, (StatusCode, &'static str)> {
    let conn = state.db.conn();
    let (_, filename): (i64, String) = conn
        .query_row(
            "SELECT instance_id, filename FROM backups WHERE id = ?1",
            params![backup_id],
            |row| Ok((row.get(0)?, row.get(1)?)),
        )
        .map_err(|_| (StatusCode::NOT_FOUND, "Backup not found"))?;
    drop(conn);

    let backup_path = state
        .config
        .server_directory
        .join("backups")
        .join(&filename);

    let content =
        std::fs::read(&backup_path).map_err(|_| (StatusCode::NOT_FOUND, "File not found"))?;

    Ok(Response::builder()
        .header(header::CONTENT_TYPE, "application/zip")
        .header(
            header::CONTENT_DISPOSITION,
            format!("attachment; filename=\"{filename}\""),
        )
        .body(Body::from(content))
        .unwrap())
}