package db

import (
	"database/sql"
	"fmt"

	"git.pengzhan.dev/haopengzhan/hireme/internal/logger"
	_ "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)
	}

	logger.Log.Infow("SQLite database initialized successfully", "component", "DB", "dbPath", 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,
		last_seen_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,
		filter_score REAL DEFAULT 0.0,
		score REAL DEFAULT 0.0,
		is_qualified BOOLEAN NOT NULL DEFAULT 0,
		summary TEXT,
		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
	);
	`

	if _, err := db.Exec(schema); err != nil {
		return err
	}

	// Dynamic migration for existing databases: check if last_seen_at exists in raw_jobs
	var hasLastSeen bool
	rows, err := db.Query(`PRAGMA table_info(raw_jobs)`)
	if err == nil {
		for rows.Next() {
			var cid int
			var name, ctype string
			var notnull, pk int
			var dfltValue sql.NullString
			if err := rows.Scan(&cid, &name, &ctype, &notnull, &dfltValue, &pk); err == nil {
				if name == "last_seen_at" {
					hasLastSeen = true
					break
				}
			}
		}
		_ = rows.Close()
	}

	if !hasLastSeen {
		if _, err := db.Exec(`ALTER TABLE raw_jobs ADD COLUMN last_seen_at DATETIME`); err != nil {
			logger.Log.Warnw("Failed to add last_seen_at column", "component", "DB", "error", err)
		} else {
			_, _ = db.Exec(`UPDATE raw_jobs SET last_seen_at = crawled_at WHERE last_seen_at IS NULL`)
			_, _ = db.Exec(`UPDATE raw_jobs SET last_seen_at = CURRENT_TIMESTAMP WHERE last_seen_at IS NULL`)
		}
	}

	// Dynamic migration for job_analyses: check if filter_score and summary exist
	var hasFilterScore, hasSummary bool
	rowsA, err := db.Query(`PRAGMA table_info(job_analyses)`)
	if err == nil {
		for rowsA.Next() {
			var cid int
			var name, ctype string
			var notnull, pk int
			var dfltValue sql.NullString
			if err := rowsA.Scan(&cid, &name, &ctype, &notnull, &dfltValue, &pk); err == nil {
				if name == "filter_score" {
					hasFilterScore = true
				}
				if name == "summary" {
					hasSummary = true
				}
			}
		}
		_ = rowsA.Close()
	}

	if !hasFilterScore {
		if _, err := db.Exec(`ALTER TABLE job_analyses ADD COLUMN filter_score REAL DEFAULT 0.0`); err != nil {
			logger.Log.Warnw("Failed to add filter_score column", "component", "DB", "error", err)
		} else {
			_, _ = db.Exec(`UPDATE job_analyses SET filter_score = score WHERE filter_score IS NULL OR filter_score = 0.0`)
		}
	}

	if !hasSummary {
		if _, err := db.Exec(`ALTER TABLE job_analyses ADD COLUMN summary TEXT`); err != nil {
			logger.Log.Warnw("Failed to add summary column", "component", "DB", "error", err)
		}
	}

	return nil
}