package db

import (
	"database/sql"
	"fmt"
	"log"

	_ "github.com/mattn/go-sqlite3"
)

type DB struct {
	*sql.DB
}

func InitDB(dbPath string) (*DB, error) {
	if dbPath == "" {
		dbPath = "data/db/hireme.db"
	}

	conn, err := sql.Open("sqlite3", dbPath+"?_foreign_keys=on&_busy_timeout=5000&_journal_mode=WAL&_txlock=immediate")
	if err != nil {
		return nil, fmt.Errorf("failed to open sqlite database: %w", err)
	}

	if err := conn.Ping(); err != nil {
		return nil, fmt.Errorf("failed to ping sqlite database: %w", err)
	}

	database := &DB{DB: conn}
	if err := database.migrate(); err != nil {
		return nil, fmt.Errorf("failed to run sqlite migrations: %w", err)
	}

	log.Printf("[DB] SQLite database initialized successfully at %s", dbPath)
	return database, nil
}

func (db *DB) migrate() error {
	schema := `
	CREATE TABLE IF NOT EXISTS search_targets (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		name TEXT NOT NULL,
		target_url TEXT NOT NULL,
		platform TEXT NOT NULL,
		is_active BOOLEAN NOT NULL DEFAULT 1,
		last_crawled_at DATETIME
	);

	CREATE TABLE IF NOT EXISTS raw_jobs (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		canonical_id TEXT UNIQUE NOT NULL,
		target_id INTEGER REFERENCES search_targets(id),
		title TEXT NOT NULL,
		company TEXT NOT NULL,
		location TEXT,
		apply_url TEXT NOT NULL,
		raw_content TEXT NOT NULL,
		crawled_at DATETIME DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS job_analyses (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		raw_job_id INTEGER UNIQUE NOT NULL REFERENCES raw_jobs(id) ON DELETE CASCADE,
		score REAL DEFAULT 0.0,
		is_qualified BOOLEAN NOT NULL DEFAULT 0,
		matched_highlights JSON,
		missing_highlights JSON,
		tailoring_suggestions JSON,
		status TEXT NOT NULL DEFAULT 'PENDING',
		analyzed_at DATETIME
	);

	CREATE TABLE IF NOT EXISTS job_applications (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		raw_job_id INTEGER UNIQUE NOT NULL REFERENCES raw_jobs(id) ON DELETE CASCADE,
		status TEXT NOT NULL DEFAULT 'SAVED',
		notes TEXT,
		applied_at DATETIME,
		updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS tasks (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		task_type TEXT NOT NULL,
		payload TEXT NOT NULL,
		status TEXT NOT NULL DEFAULT 'PENDING',
		error_message TEXT,
		retry_count INTEGER DEFAULT 0,
		next_retry_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
	);
	`

	_, err := db.Exec(schema)
	return err
}