package database

import (
	"database/sql"
	"fmt"

	_ "github.com/jackc/pgx/v5/stdlib"

	"rag/file-system/internal/common"
)

func NewPostgresDB(databaseURL string) (*sql.DB, error) {
	db, err := sql.Open("pgx", databaseURL)
	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)
	}

	db.SetMaxOpenConns(25)
	db.SetMaxIdleConns(5)

	common.Logger.Info("connected to PostgreSQL")
	return db, nil
}

func RunMigrations(db *sql.DB) error {
	migrations := []string{
		`CREATE TABLE IF NOT EXISTS folders (
			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
			parent_id UUID REFERENCES folders(id) ON DELETE CASCADE,
			name VARCHAR(255) NOT NULL,
			owner_id VARCHAR(36) NOT NULL,
			created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
			updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
			UNIQUE(parent_id, name, owner_id)
		)`,
		`CREATE INDEX IF NOT EXISTS idx_folders_parent ON folders(parent_id)`,
		`CREATE INDEX IF NOT EXISTS idx_folders_owner ON folders(owner_id)`,

		`CREATE TABLE IF NOT EXISTS files (
			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
			folder_id UUID REFERENCES folders(id) ON DELETE CASCADE,
			name VARCHAR(255) NOT NULL,
			s3_key VARCHAR(512) NOT NULL,
			s3_bucket VARCHAR(255) NOT NULL,
			size BIGINT NOT NULL DEFAULT 0,
			content_type VARCHAR(255) NOT NULL DEFAULT 'application/octet-stream',
			owner_id VARCHAR(36) NOT NULL,
			created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
			updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
		)`,
		`CREATE INDEX IF NOT EXISTS idx_files_folder ON files(folder_id)`,
		`CREATE INDEX IF NOT EXISTS idx_files_owner ON files(owner_id)`,
		`CREATE INDEX IF NOT EXISTS idx_files_s3_key ON files(s3_key)`,

		`CREATE TABLE IF NOT EXISTS share_links (
			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
			resource_type VARCHAR(10) NOT NULL,
			resource_id UUID NOT NULL,
			token VARCHAR(32) NOT NULL UNIQUE,
			password VARCHAR(255),
			expires_at TIMESTAMPTZ,
			download_count INT NOT NULL DEFAULT 0,
			max_downloads INT,
			created_by VARCHAR(36) NOT NULL,
			created_at TIMESTAMPTZ NOT NULL DEFAULT now()
		)`,
		`CREATE INDEX IF NOT EXISTS idx_share_token ON share_links(token)`,
		`CREATE INDEX IF NOT EXISTS idx_share_resource ON share_links(resource_type, resource_id)`,
	}

	for _, m := range migrations {
		if _, err := db.Exec(m); err != nil {
			return fmt.Errorf("migration failed: %w\nSQL: %s", err, m)
		}
	}

	common.Logger.Info("database migrations completed")
	return nil
}