package database

import (
	"context"
	"fmt"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"
)

type DownloadFile struct {
	ID         string
	DownloadID string
	TrackID    *string
	FilePath   string
	FileSize   int64
	FileType   string
	SHA256Hash string
	VerifiedAt *time.Time
	CreatedAt  time.Time
}

type DownloadFileRepository struct {
	pool *pgxpool.Pool
}

func NewDownloadFileRepository(pool *pgxpool.Pool) *DownloadFileRepository {
	return &DownloadFileRepository{pool: pool}
}

func (r *DownloadFileRepository) Create(ctx context.Context, f *DownloadFile) error {
	err := r.pool.QueryRow(ctx,
		`INSERT INTO download_files (download_id, track_id, file_path, file_size, file_type, sha256_hash)
		 VALUES ($1, $2, $3, $4, $5, $6)
		 RETURNING id, created_at`,
		f.DownloadID, f.TrackID, f.FilePath, f.FileSize, f.FileType, f.SHA256Hash,
	).Scan(&f.ID, &f.CreatedAt)
	if err != nil {
		return fmt.Errorf("creating download file: %w", err)
	}
	return nil
}

func (r *DownloadFileRepository) CreateBatch(ctx context.Context, files []*DownloadFile) error {
	for _, f := range files {
		if err := r.Create(ctx, f); err != nil {
			return err
		}
	}
	return nil
}

func (r *DownloadFileRepository) GetByDownloadID(ctx context.Context, downloadID string) ([]*DownloadFile, error) {
	rows, err := r.pool.Query(ctx,
		`SELECT id, download_id, track_id, file_path, file_size, file_type, sha256_hash, verified_at, created_at
		 FROM download_files WHERE download_id = $1 ORDER BY file_path`, downloadID,
	)
	if err != nil {
		return nil, fmt.Errorf("listing download files: %w", err)
	}
	defer rows.Close()

	var files []*DownloadFile
	for rows.Next() {
		f := &DownloadFile{}
		if err := rows.Scan(&f.ID, &f.DownloadID, &f.TrackID, &f.FilePath, &f.FileSize, &f.FileType, &f.SHA256Hash, &f.VerifiedAt, &f.CreatedAt); err != nil {
			return nil, fmt.Errorf("scanning download file: %w", err)
		}
		files = append(files, f)
	}
	return files, nil
}

func (r *DownloadFileRepository) SetHash(ctx context.Context, id string, hash string) error {
	_, err := r.pool.Exec(ctx,
		`UPDATE download_files SET sha256_hash = $1, verified_at = NOW() WHERE id = $2`, hash, id,
	)
	if err != nil {
		return fmt.Errorf("setting file hash: %w", err)
	}
	return nil
}

func (r *DownloadFileRepository) GetUnverified(ctx context.Context) ([]*DownloadFile, error) {
	rows, err := r.pool.Query(ctx,
		`SELECT id, download_id, track_id, file_path, file_size, file_type, sha256_hash, verified_at, created_at
		 FROM download_files WHERE sha256_hash IS NULL OR verified_at < NOW() - INTERVAL '30 days'
		 ORDER BY created_at`,
	)
	if err != nil {
		return nil, fmt.Errorf("listing unverified files: %w", err)
	}
	defer rows.Close()

	var files []*DownloadFile
	for rows.Next() {
		f := &DownloadFile{}
		if err := rows.Scan(&f.ID, &f.DownloadID, &f.TrackID, &f.FilePath, &f.FileSize, &f.FileType, &f.SHA256Hash, &f.VerifiedAt, &f.CreatedAt); err != nil {
			return nil, fmt.Errorf("scanning download file: %w", err)
		}
		files = append(files, f)
	}
	return files, nil
}