package db

import (
	"database/sql"
	"fmt"
	"time"

	"github.com/insertr/server/internal/models"
	_ "github.com/mattn/go-sqlite3"
)

// SQLiteDB wraps a SQLite database connection
type SQLiteDB struct {
	db *sql.DB
}

// NewSQLiteDB creates a new SQLite database connection
func NewSQLiteDB(dbPath string) (*SQLiteDB, error) {
	db, err := sql.Open("sqlite3", dbPath)
	if err != nil {
		return nil, fmt.Errorf("opening database: %w", err)
	}

	// Test connection
	if err := db.Ping(); err != nil {
		return nil, fmt.Errorf("connecting to database: %w", err)
	}

	sqliteDB := &SQLiteDB{db: db}

	// Initialize schema
	if err := sqliteDB.initSchema(); err != nil {
		return nil, fmt.Errorf("initializing schema: %w", err)
	}

	return sqliteDB, nil
}

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

// initSchema creates the necessary tables
func (s *SQLiteDB) initSchema() error {
	schema := `
	CREATE TABLE IF NOT EXISTS content (
		id TEXT NOT NULL,
		site_id TEXT NOT NULL,
		value TEXT NOT NULL,
		type TEXT NOT NULL CHECK (type IN ('text', 'markdown', 'link')),
		created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		PRIMARY KEY (id, site_id)
	);

	CREATE INDEX IF NOT EXISTS idx_content_site_id ON content(site_id);
	CREATE INDEX IF NOT EXISTS idx_content_updated_at ON content(updated_at);

	-- Trigger to update updated_at timestamp
	CREATE TRIGGER IF NOT EXISTS update_content_updated_at
	AFTER UPDATE ON content
	FOR EACH ROW
	BEGIN
		UPDATE content SET updated_at = CURRENT_TIMESTAMP WHERE id = NEW.id AND site_id = NEW.site_id;
	END;
	`

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

	return nil
}

// GetContent fetches a single content item by ID and site ID
func (s *SQLiteDB) GetContent(siteID, contentID string) (*models.ContentItem, error) {
	query := `
		SELECT id, site_id, value, type, created_at, updated_at 
		FROM content 
		WHERE id = ? AND site_id = ?
	`

	var item models.ContentItem
	err := s.db.QueryRow(query, contentID, siteID).Scan(
		&item.ID, &item.SiteID, &item.Value, &item.Type, &item.CreatedAt, &item.UpdatedAt,
	)

	if err == sql.ErrNoRows {
		return nil, nil // Content not found
	}
	if err != nil {
		return nil, fmt.Errorf("querying content: %w", err)
	}

	return &item, nil
}

// GetAllContent fetches all content for a site
func (s *SQLiteDB) GetAllContent(siteID string) ([]models.ContentItem, error) {
	query := `
		SELECT id, site_id, value, type, created_at, updated_at 
		FROM content 
		WHERE site_id = ? 
		ORDER BY updated_at DESC
	`

	rows, err := s.db.Query(query, siteID)
	if err != nil {
		return nil, fmt.Errorf("querying all content: %w", err)
	}
	defer rows.Close()

	var items []models.ContentItem
	for rows.Next() {
		var item models.ContentItem
		err := rows.Scan(&item.ID, &item.SiteID, &item.Value, &item.Type, &item.CreatedAt, &item.UpdatedAt)
		if err != nil {
			return nil, fmt.Errorf("scanning content row: %w", err)
		}
		items = append(items, item)
	}

	if err := rows.Err(); err != nil {
		return nil, fmt.Errorf("iterating content rows: %w", err)
	}

	return items, nil
}

// GetBulkContent fetches multiple content items by IDs
func (s *SQLiteDB) GetBulkContent(siteID string, contentIDs []string) ([]models.ContentItem, error) {
	if len(contentIDs) == 0 {
		return []models.ContentItem{}, nil
	}

	// Build placeholders for IN clause
	placeholders := make([]interface{}, len(contentIDs)+1)
	placeholders[0] = siteID
	for i, id := range contentIDs {
		placeholders[i+1] = id
	}

	// Build query with proper number of placeholders
	query := fmt.Sprintf(`
		SELECT id, site_id, value, type, created_at, updated_at 
		FROM content 
		WHERE site_id = ? AND id IN (%s)
		ORDER BY updated_at DESC
	`, buildPlaceholders(len(contentIDs)))

	rows, err := s.db.Query(query, placeholders...)
	if err != nil {
		return nil, fmt.Errorf("querying bulk content: %w", err)
	}
	defer rows.Close()

	var items []models.ContentItem
	for rows.Next() {
		var item models.ContentItem
		err := rows.Scan(&item.ID, &item.SiteID, &item.Value, &item.Type, &item.CreatedAt, &item.UpdatedAt)
		if err != nil {
			return nil, fmt.Errorf("scanning bulk content row: %w", err)
		}
		items = append(items, item)
	}

	return items, nil
}

// CreateContent creates a new content item
func (s *SQLiteDB) CreateContent(siteID, contentID, value, contentType string) (*models.ContentItem, error) {
	now := time.Now()

	query := `
		INSERT INTO content (id, site_id, value, type, created_at, updated_at)
		VALUES (?, ?, ?, ?, ?, ?)
	`

	_, err := s.db.Exec(query, contentID, siteID, value, contentType, now, now)
	if err != nil {
		return nil, fmt.Errorf("creating content: %w", err)
	}

	return &models.ContentItem{
		ID:        contentID,
		SiteID:    siteID,
		Value:     value,
		Type:      contentType,
		CreatedAt: now,
		UpdatedAt: now,
	}, nil
}

// UpdateContent updates an existing content item
func (s *SQLiteDB) UpdateContent(siteID, contentID, value string) (*models.ContentItem, error) {
	// First check if content exists
	existing, err := s.GetContent(siteID, contentID)
	if err != nil {
		return nil, fmt.Errorf("checking existing content: %w", err)
	}
	if existing == nil {
		return nil, fmt.Errorf("content not found: %s", contentID)
	}

	query := `
		UPDATE content 
		SET value = ?, updated_at = CURRENT_TIMESTAMP 
		WHERE id = ? AND site_id = ?
	`

	_, err = s.db.Exec(query, value, contentID, siteID)
	if err != nil {
		return nil, fmt.Errorf("updating content: %w", err)
	}

	// Fetch and return updated content
	return s.GetContent(siteID, contentID)
}

// buildPlaceholders creates a string of SQL placeholders like "?,?,?"
func buildPlaceholders(count int) string {
	if count == 0 {
		return ""
	}

	result := "?"
	for i := 1; i < count; i++ {
		result += ",?"
	}
	return result
}