package repo

import (
	"context"
	"fmt"
	"github.com/ente-io/stacktrace"
	"github.com/lib/pq"
)

// GetCollectionFileIDs return list of fileIDs are  currently present in the given collection
// and fileIDs are owned by the collection owner
func (repo *CollectionRepository) GetCollectionFileIDs(collectionID int64, collectionOwnerID int64) ([]int64, error) {
	// Collaboration Todo: Filter out files which are not owned by the collection owner
	rows, err := repo.DB.Query(
		`SELECT file_id   
			FROM collection_files
			WHERE is_deleted=false
				AND collection_id =$1 AND (f_owner_id is null or f_owner_id = $2)`, collectionID, collectionOwnerID)
	if err != nil {
		return make([]int64, 0), stacktrace.Propagate(err, "")
	}
	return convertRowsToFileId(rows)
}

// DoesFileExistInCollections returns true if the file exists in one of the
// provided collections
func (repo *CollectionRepository) DoesFileExistInCollections(fileID int64, cIDs []int64) (bool, error) {
	var exists bool
	err := repo.DB.QueryRow(`SELECT EXISTS (SELECT 1 FROM collection_files WHERE file_id = $1 AND is_deleted = $2 AND collection_id = ANY ($3))`,
		fileID, false, pq.Array(cIDs)).Scan(&exists)
	return exists, stacktrace.Propagate(err, "")
}

func (repo *CollectionRepository) DoAllFilesExistInGivenCollections(fileIDs []int64, cIDs []int64) error {
	// Query to get all distinct file_ids that exist in the collections
	rows, err := repo.DB.Query(`
        SELECT DISTINCT file_id 
        FROM collection_files 
        WHERE file_id = ANY ($1) 
        AND is_deleted = false 
        AND collection_id = ANY ($2)`,
		pq.Array(fileIDs), pq.Array(cIDs))

	if err != nil {
		return stacktrace.Propagate(err, "")
	}
	defer rows.Close()

	// Create a map of input fileIDs for easy lookup
	fileIDMap := make(map[int64]bool)
	for _, id := range fileIDs {
		fileIDMap[id] = false // false means not found yet
	}
	// Mark files that were found
	for rows.Next() {
		var fileID int64
		if err := rows.Scan(&fileID); err != nil {
			return stacktrace.Propagate(err, "")
		}
		fileIDMap[fileID] = true // mark as found
	}

	if err = rows.Err(); err != nil {
		return stacktrace.Propagate(err, "")
	}

	// Collect missing files
	var missingFiles []int64
	for id, found := range fileIDMap {
		if !found {
			missingFiles = append(missingFiles, id)
		}
	}
	if len(missingFiles) > 0 {
		return stacktrace.Propagate(fmt.Errorf("missing files %v", missingFiles), "")
	}
	return nil
}

// VerifyAllFileIDsExistsInCollection returns error if the fileIDs don't exist in the collection
func (repo *CollectionRepository) VerifyAllFileIDsExistsInCollection(ctx context.Context, cID int64, fileIDs []int64) error {
	fileIdMap := make(map[int64]bool)
	rows, err := repo.DB.QueryContext(ctx, `SELECT file_id FROM collection_files WHERE collection_id = $1 AND is_deleted = $2 AND file_id = ANY ($3)`,
		cID, false, pq.Array(fileIDs))
	if err != nil {
		return stacktrace.Propagate(err, "")
	}
	for rows.Next() {
		var fileID int64
		if err := rows.Scan(&fileID); err != nil {
			return stacktrace.Propagate(err, "")
		}
		fileIdMap[fileID] = true
	}
	// find fileIds that are not present in the collection
	for _, fileID := range fileIDs {
		if _, ok := fileIdMap[fileID]; !ok {
			return stacktrace.Propagate(fmt.Errorf("fileID %d not found in collection %d", fileID, cID), "")
		}
	}
	return nil
}

// GetCollectionsFilesCount returns the number of non-deleted files which are present in the given collection
func (repo *CollectionRepository) GetCollectionsFilesCount(collectionID int64) (int64, error) {
	row := repo.DB.QueryRow(`SELECT count(*) FROM collection_files WHERE collection_id=$1 AND is_deleted = false`, collectionID)
	var count int64 = 0
	err := row.Scan(&count)
	if err != nil {
		return -1, stacktrace.Propagate(err, "")
	}
	return count, nil
}

func (repo *CollectionRepository) GetCollectionCount(fileID int64) (int64, error) {
	row := repo.DB.QueryRow(`SELECT count(*) FROM collection_files WHERE file_id = $1 and is_deleted = false`, fileID)
	var count int64 = 0
	err := row.Scan(&count)
	if err != nil {
		return -1, stacktrace.Propagate(err, "")
	}
	return count, nil
}