package database

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

	_ "github.com/marcboeker/go-duckdb/v2"
)

// DB wraps the database connection
type DB struct {
	*sql.DB
}

// NewDB creates a new database connection
func NewDB(dbPath string) (*DB, error) {
	db, err := sql.Open("duckdb", dbPath)
	if err != nil {
		return nil, fmt.Errorf("failed to open database: %w", err)
	}

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

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

	return database, nil
}

// migrate runs database migrations
func (db *DB) migrate() error {
	// Create sequences for auto-incrementing primary keys
	sequences := []string{
		`CREATE SEQUENCE IF NOT EXISTS seq_users_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_jobs_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_runners_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_tasks_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_job_files_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_manager_secrets_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_registration_tokens_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_task_logs_id START 1`,
		`CREATE SEQUENCE IF NOT EXISTS seq_task_steps_id START 1`,
	}

	for _, seq := range sequences {
		if _, err := db.Exec(seq); err != nil {
			return fmt.Errorf("failed to create sequence: %w", err)
		}
	}

	schema := `
	CREATE TABLE IF NOT EXISTS users (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_users_id'),
		email TEXT UNIQUE NOT NULL,
		name TEXT NOT NULL,
		oauth_provider TEXT NOT NULL,
		oauth_id TEXT NOT NULL,
		password_hash TEXT,
		is_admin BOOLEAN NOT NULL DEFAULT false,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
		UNIQUE(oauth_provider, oauth_id)
	);

	CREATE TABLE IF NOT EXISTS jobs (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_jobs_id'),
		user_id BIGINT NOT NULL,
		job_type TEXT NOT NULL DEFAULT 'render',
		name TEXT NOT NULL,
		status TEXT NOT NULL DEFAULT 'pending',
		progress REAL NOT NULL DEFAULT 0.0,
		frame_start INTEGER,
		frame_end INTEGER,
		output_format TEXT,
		allow_parallel_runners BOOLEAN,
		timeout_seconds INTEGER DEFAULT 86400,
		blend_metadata TEXT,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
		started_at TIMESTAMP,
		completed_at TIMESTAMP,
		error_message TEXT,
		FOREIGN KEY (user_id) REFERENCES users(id)
	);

	CREATE TABLE IF NOT EXISTS runners (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_runners_id'),
		name TEXT NOT NULL,
		hostname TEXT NOT NULL,
		ip_address TEXT NOT NULL,
		status TEXT NOT NULL DEFAULT 'offline',
		last_heartbeat TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
		capabilities TEXT,
		registration_token TEXT,
		runner_secret TEXT,
		manager_secret TEXT,
		verified BOOLEAN NOT NULL DEFAULT false,
		priority INTEGER NOT NULL DEFAULT 100,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS tasks (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_tasks_id'),
		job_id BIGINT NOT NULL,
		runner_id BIGINT,
		frame_start INTEGER NOT NULL,
		frame_end INTEGER NOT NULL,
		status TEXT NOT NULL DEFAULT 'pending',
		output_path TEXT,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
		started_at TIMESTAMP,
		completed_at TIMESTAMP,
		error_message TEXT
	);

	CREATE TABLE IF NOT EXISTS job_files (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_job_files_id'),
		job_id BIGINT NOT NULL,
		file_type TEXT NOT NULL,
		file_path TEXT NOT NULL,
		file_name TEXT NOT NULL,
		file_size BIGINT NOT NULL,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS manager_secrets (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_manager_secrets_id'),
		secret TEXT UNIQUE NOT NULL,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS registration_tokens (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_registration_tokens_id'),
		token TEXT UNIQUE NOT NULL,
		expires_at TIMESTAMP NOT NULL,
		used BOOLEAN NOT NULL DEFAULT false,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
		created_by BIGINT,
		FOREIGN KEY (created_by) REFERENCES users(id)
	);

	CREATE TABLE IF NOT EXISTS task_logs (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_task_logs_id'),
		task_id BIGINT NOT NULL,
		runner_id BIGINT,
		log_level TEXT NOT NULL,
		message TEXT NOT NULL,
		step_name TEXT,
		created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
	);

	CREATE TABLE IF NOT EXISTS task_steps (
		id BIGINT PRIMARY KEY DEFAULT nextval('seq_task_steps_id'),
		task_id BIGINT NOT NULL,
		step_name TEXT NOT NULL,
		status TEXT NOT NULL DEFAULT 'pending',
		started_at TIMESTAMP,
		completed_at TIMESTAMP,
		duration_ms INTEGER,
		error_message TEXT
	);

	CREATE INDEX IF NOT EXISTS idx_jobs_user_id ON jobs(user_id);
	CREATE INDEX IF NOT EXISTS idx_jobs_status ON jobs(status);
	CREATE INDEX IF NOT EXISTS idx_tasks_job_id ON tasks(job_id);
	CREATE INDEX IF NOT EXISTS idx_tasks_runner_id ON tasks(runner_id);
	CREATE INDEX IF NOT EXISTS idx_tasks_status ON tasks(status);
	CREATE INDEX IF NOT EXISTS idx_tasks_started_at ON tasks(started_at);
	CREATE INDEX IF NOT EXISTS idx_job_files_job_id ON job_files(job_id);
	CREATE INDEX IF NOT EXISTS idx_registration_tokens_token ON registration_tokens(token);
	CREATE INDEX IF NOT EXISTS idx_registration_tokens_expires_at ON registration_tokens(expires_at);
	CREATE INDEX IF NOT EXISTS idx_task_logs_task_id_created_at ON task_logs(task_id, created_at);
	CREATE INDEX IF NOT EXISTS idx_task_logs_runner_id ON task_logs(runner_id);
	CREATE INDEX IF NOT EXISTS idx_task_steps_task_id ON task_steps(task_id);
	CREATE INDEX IF NOT EXISTS idx_runners_last_heartbeat ON runners(last_heartbeat);

	CREATE TABLE IF NOT EXISTS settings (
		key TEXT PRIMARY KEY,
		value TEXT NOT NULL,
		updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
	);
	`

	if _, err := db.Exec(schema); err != nil {
		return fmt.Errorf("failed to create schema: %w", err)
	}

	// Migrate existing tables to add new columns
	migrations := []string{
		// Add is_admin to users if it doesn't exist
		`ALTER TABLE users ADD COLUMN IF NOT EXISTS is_admin BOOLEAN NOT NULL DEFAULT false`,
		// Add new columns to runners if they don't exist
		`ALTER TABLE runners ADD COLUMN IF NOT EXISTS registration_token TEXT`,
		`ALTER TABLE runners ADD COLUMN IF NOT EXISTS runner_secret TEXT`,
		`ALTER TABLE runners ADD COLUMN IF NOT EXISTS manager_secret TEXT`,
		`ALTER TABLE runners ADD COLUMN IF NOT EXISTS verified BOOLEAN NOT NULL DEFAULT false`,
		`ALTER TABLE runners ADD COLUMN IF NOT EXISTS priority INTEGER NOT NULL DEFAULT 100`,
		// Add allow_parallel_runners to jobs if it doesn't exist
		`ALTER TABLE jobs ADD COLUMN IF NOT EXISTS allow_parallel_runners BOOLEAN NOT NULL DEFAULT true`,
		// Add timeout_seconds to jobs if it doesn't exist
		`ALTER TABLE jobs ADD COLUMN IF NOT EXISTS timeout_seconds INTEGER DEFAULT 86400`,
		// Add blend_metadata to jobs if it doesn't exist
		`ALTER TABLE jobs ADD COLUMN IF NOT EXISTS blend_metadata TEXT`,
		// Add job_type to jobs if it doesn't exist
		`ALTER TABLE jobs ADD COLUMN IF NOT EXISTS job_type TEXT DEFAULT 'render'`,
		// Add task_type to tasks if it doesn't exist
		`ALTER TABLE tasks ADD COLUMN IF NOT EXISTS task_type TEXT DEFAULT 'render'`,
		// Add new columns to tasks if they don't exist
		`ALTER TABLE tasks ADD COLUMN IF NOT EXISTS current_step TEXT`,
		`ALTER TABLE tasks ADD COLUMN IF NOT EXISTS retry_count INTEGER DEFAULT 0`,
		`ALTER TABLE tasks ADD COLUMN IF NOT EXISTS max_retries INTEGER DEFAULT 3`,
		`ALTER TABLE tasks ADD COLUMN IF NOT EXISTS timeout_seconds INTEGER`,
		// Migrate file_size from INTEGER to BIGINT to support large files (>2GB)
		// DuckDB doesn't support direct ALTER COLUMN TYPE, so we use a workaround:
		// 1. Add new column as BIGINT
		// 2. Copy data from old column
		// 3. Drop old column
		// 4. Rename new column
		// Note: This will only run if the column exists and is INTEGER
		`ALTER TABLE job_files ADD COLUMN IF NOT EXISTS file_size_new BIGINT`,
		`UPDATE job_files SET file_size_new = CAST(file_size AS BIGINT) WHERE file_size_new IS NULL`,
		`ALTER TABLE job_files DROP COLUMN IF EXISTS file_size`,
		`ALTER TABLE job_files RENAME COLUMN file_size_new TO file_size`,
	}

	for _, migration := range migrations {
		// DuckDB supports IF NOT EXISTS for ALTER TABLE, so we can safely execute
		if _, err := db.Exec(migration); err != nil {
			// Log but don't fail - column might already exist or table might not exist yet
			// This is fine for migrations that run after schema creation
			// For the file_size migration, if it fails (e.g., already BIGINT), that's fine
		}
	}

	// Initialize registration_enabled setting (default: true) if it doesn't exist
	var settingCount int
	err := db.QueryRow("SELECT COUNT(*) FROM settings WHERE key = ?", "registration_enabled").Scan(&settingCount)
	if err == nil && settingCount == 0 {
		_, err = db.Exec("INSERT INTO settings (key, value) VALUES (?, ?)", "registration_enabled", "true")
		if err != nil {
			// Log but don't fail - setting might have been created by another process
			log.Printf("Note: Could not initialize registration_enabled setting: %v", err)
		}
	}

	return nil
}

// Close closes the database connection
func (db *DB) Close() error {
	return db.DB.Close()
}