use chrono::{Local, NaiveDate};
use rusqlite::{Connection, Result};
use serde::Serialize;
use std::fs;
use tauri::Manager;

fn init_database(app: &tauri::App) -> Result<(), Box<dyn std::error::Error>> {
    // 获取应用数据目录
    let app_dir = app.path().app_data_dir()?;

    // 确保目录存在
    fs::create_dir_all(&app_dir)?;

    // 构建数据库文件路径
    let db_path = app_dir.join("anniversaries.db");

    // 打开数据库连接
    let conn = Connection::open(db_path)?;

    // 创建表
    conn.execute(
        "CREATE TABLE IF NOT EXISTS anniversaries (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            title TEXT NOT NULL,
            start_date TEXT NOT NULL,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP
        )",
        [],
    )?;

    Ok(())
}

#[derive(Serialize)]
struct Anniversary {
    id: i32,
    title: String,
    start_date: String,
    days: i64,
}
#[tauri::command]
async fn get_anniversaries(app_handle: tauri::AppHandle) -> Result<Vec<Anniversary>, String> {
    // 返回主页数据
    let app_dir = app_handle
        .path()
        .app_data_dir()
        .map_err(|e| e.to_string())?;
    let db_path = app_dir.join("anniversaries.db");
    let conn = Connection::open(db_path).map_err(|e| e.to_string())?;

    let mut stmt = conn
        .prepare("SELECT id, title, start_date FROM anniversaries ORDER BY created_at DESC")
        .map_err(|e| e.to_string())?;

    let today = Local::now().date_naive();

    let anniversaries = stmt
        .query_map([], |row| {
            let id: i32 = row.get(0)?;
            let title: String = row.get(1)?;
            let start_date: String = row.get(2)?;

            // 计算天数
            let start = NaiveDate::parse_from_str(&start_date, "%Y-%m-%d")
                .map_err(|e| rusqlite::Error::InvalidParameterName(e.to_string()))?;
            let days = (today - start).num_days();

            Ok(Anniversary {
                id,
                title,
                start_date,
                days,
            })
        })
        .map_err(|e| e.to_string())?;

    let result: Result<Vec<_>, _> = anniversaries.collect();
    result.map_err(|e| e.to_string())
}

#[tauri::command]
async fn get_anniversary_by_id(
    app_handle: tauri::AppHandle,
    id: i32,
) -> Result<Anniversary, String> {
    // 返回详情页数据
    let app_dir = app_handle
        .path()
        .app_data_dir()
        .map_err(|e| e.to_string())?;
    let db_path = app_dir.join("anniversaries.db");
    let conn = Connection::open(db_path).map_err(|e| e.to_string())?;
    let mut stmt = conn
        .prepare("SELECT title, start_date FROM anniversaries WHERE id = ?")
        .map_err(|e| e.to_string())?;

    let today = Local::now().date_naive();

    let result = stmt
        .query_row([id], |row| {
            let title: String = row.get(0)?;
            let start_date: String = row.get(1)?;

            // 计算天数
            let start = NaiveDate::parse_from_str(&start_date, "%Y-%m-%d")
                .map_err(|e| rusqlite::Error::InvalidParameterName(e.to_string()))?;
            let days = (today - start).num_days();

            Ok(Anniversary {
                id,
                title,
                start_date,
                days,
            })
        })
        .map_err(|e| e.to_string())?;

    Ok(result)
}

#[tauri::command]
async fn delete_anniversary(app_handle: tauri::AppHandle, id: i64) -> Result<(), String> {
    // 详情页删除
    let app_dir = app_handle
        .path()
        .app_data_dir()
        .map_err(|e| e.to_string())?;
    let db_path = app_dir.join("anniversaries.db");
    let conn = Connection::open(db_path).map_err(|e| e.to_string())?;
    conn.execute("DELETE FROM anniversaries WHERE id = ?", [id])
        .map_err(|e| e.to_string())?;

    Ok(())
}

#[tauri::command]
async fn add_anniversary(
    app_handle: tauri::AppHandle,
    title: String,
    start_date: String,
) -> Result<(), String> {
    // 主页添加
    let app_dir = app_handle
        .path()
        .app_data_dir()
        .map_err(|e| e.to_string())?;
    let db_path = app_dir.join("anniversaries.db");
    let conn = Connection::open(db_path).map_err(|e| e.to_string())?;
    conn.execute(
        "INSERT INTO anniversaries (title, start_date) VALUES (?1, ?2)",
        [&title, &start_date],
    )
    .map_err(|e| e.to_string())?;

    Ok(())
}

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    tauri::Builder::default()
        .plugin(tauri_plugin_opener::init())
        .setup(|app| {
            init_database(app).expect("failed to initialize database");
            Ok(())
        })
        .invoke_handler(tauri::generate_handler![
            get_anniversaries,
            get_anniversary_by_id,
            add_anniversary,
            delete_anniversary,
        ])
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}