package db

import (
	"context"
	"database/sql"
	"encoding/json"
	"time"
)

type UploadedFile struct {
	ID            string                 `json:"id"`
	UserID        string                 `json:"userId"`
	Filename      string                 `json:"filename"`
	FileType      string                 `json:"fileType"`
	FileSize      int64                  `json:"fileSize"`
	StoragePath   string                 `json:"storagePath"`
	ExtractedText string                 `json:"extractedText,omitempty"`
	Metadata      map[string]interface{} `json:"metadata"`
	CreatedAt     time.Time              `json:"createdAt"`
}

type FileRepository struct {
	db *PostgresDB
}

func NewFileRepository(db *PostgresDB) *FileRepository {
	return &FileRepository{db: db}
}

func (r *FileRepository) Create(ctx context.Context, f *UploadedFile) error {
	metadataJSON, _ := json.Marshal(f.Metadata)

	query := `
		INSERT INTO uploaded_files (user_id, filename, file_type, file_size, storage_path, extracted_text, metadata)
		VALUES ($1, $2, $3, $4, $5, $6, $7)
		RETURNING id, created_at
	`
	return r.db.db.QueryRowContext(ctx, query,
		f.UserID, f.Filename, f.FileType, f.FileSize, f.StoragePath, f.ExtractedText, metadataJSON,
	).Scan(&f.ID, &f.CreatedAt)
}

func (r *FileRepository) GetByID(ctx context.Context, id string) (*UploadedFile, error) {
	query := `
		SELECT id, user_id, filename, file_type, file_size, storage_path, extracted_text, metadata, created_at
		FROM uploaded_files 
		WHERE id = $1
	`

	var f UploadedFile
	var metadataJSON []byte

	err := r.db.db.QueryRowContext(ctx, query, id).Scan(
		&f.ID, &f.UserID, &f.Filename, &f.FileType, &f.FileSize,
		&f.StoragePath, &f.ExtractedText, &metadataJSON, &f.CreatedAt,
	)
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	json.Unmarshal(metadataJSON, &f.Metadata)
	return &f, nil
}

func (r *FileRepository) GetByUserID(ctx context.Context, userID string, limit, offset int) ([]*UploadedFile, error) {
	query := `
		SELECT id, user_id, filename, file_type, file_size, storage_path, extracted_text, metadata, created_at
		FROM uploaded_files 
		WHERE user_id = $1
		ORDER BY created_at DESC
		LIMIT $2 OFFSET $3
	`

	rows, err := r.db.db.QueryContext(ctx, query, userID, limit, offset)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var files []*UploadedFile
	for rows.Next() {
		var f UploadedFile
		var metadataJSON []byte

		if err := rows.Scan(
			&f.ID, &f.UserID, &f.Filename, &f.FileType, &f.FileSize,
			&f.StoragePath, &f.ExtractedText, &metadataJSON, &f.CreatedAt,
		); err != nil {
			return nil, err
		}

		json.Unmarshal(metadataJSON, &f.Metadata)
		files = append(files, &f)
	}

	return files, nil
}

func (r *FileRepository) UpdateExtractedText(ctx context.Context, id, text, userID string) error {
	result, err := r.db.db.ExecContext(ctx,
		"UPDATE uploaded_files SET extracted_text = $2 WHERE id = $1 AND user_id = $3",
		id, text, userID,
	)
	if err != nil {
		return err
	}
	rows, _ := result.RowsAffected()
	if rows == 0 {
		return ErrNotFound
	}
	return nil
}

func (r *FileRepository) Delete(ctx context.Context, id, userID string) error {
	result, err := r.db.db.ExecContext(ctx, "DELETE FROM uploaded_files WHERE id = $1 AND user_id = $2", id, userID)
	if err != nil {
		return err
	}
	rows, _ := result.RowsAffected()
	if rows == 0 {
		return ErrNotFound
	}
	return nil
}

func (r *FileRepository) GetByIDs(ctx context.Context, ids []string, userID string) ([]*UploadedFile, error) {
	if len(ids) == 0 {
		return nil, nil
	}

	query := `
		SELECT id, user_id, filename, file_type, file_size, storage_path, extracted_text, metadata, created_at
		FROM uploaded_files 
		WHERE id = ANY($1) AND user_id = $2
	`

	rows, err := r.db.db.QueryContext(ctx, query, ids, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var files []*UploadedFile
	for rows.Next() {
		var f UploadedFile
		var metadataJSON []byte

		if err := rows.Scan(
			&f.ID, &f.UserID, &f.Filename, &f.FileType, &f.FileSize,
			&f.StoragePath, &f.ExtractedText, &metadataJSON, &f.CreatedAt,
		); err != nil {
			return nil, err
		}

		json.Unmarshal(metadataJSON, &f.Metadata)
		files = append(files, &f)
	}

	return files, nil
}