package db

import (
	"context"
	"strings"
)

// UpsertFileContent replaces the FTS content for a given file_id.
func (q *Queries) UpsertFileContent(ctx context.Context, fileID int64, content string) error {
	// Delete existing content for this file
	if _, err := q.db.ExecContext(ctx, `DELETE FROM file_contents WHERE file_id = ?`, fileID); err != nil {
		return err
	}
	// Insert new content
	_, err := q.db.ExecContext(ctx, `INSERT INTO file_contents (file_id, content) VALUES (?, ?)`, fileID, content)
	return err
}

// DeleteFileContentByFileID removes FTS content for a file.
func (q *Queries) DeleteFileContentByFileID(ctx context.Context, fileID int64) error {
	_, err := q.db.ExecContext(ctx, `DELETE FROM file_contents WHERE file_id = ?`, fileID)
	return err
}

// DeleteStaleFileContents removes FTS content for files not in the given path list.
func (q *Queries) DeleteStaleFileContents(ctx context.Context, paths []string) error {
	if len(paths) == 0 {
		_, err := q.db.ExecContext(ctx, `DELETE FROM file_contents`)
		return err
	}
	placeholders := make([]string, len(paths))
	args := make([]interface{}, len(paths))
	for i, p := range paths {
		placeholders[i] = "?"
		args[i] = p
	}
	query := `DELETE FROM file_contents WHERE file_id NOT IN (
		SELECT id FROM files WHERE path IN (` + strings.Join(placeholders, ",") + `)
	)`
	_, err := q.db.ExecContext(ctx, query, args...)
	return err
}

// SearchResult holds a single FTS search hit.
type SearchResult struct {
	FileID int64
	Path   string
	Snippet string
}

// SearchFileContents performs a full-text search across all file contents.
// Returns matching file paths with a snippet of the match context.
func (q *Queries) SearchFileContents(ctx context.Context, query string, limit int) ([]SearchResult, error) {
	rows, err := q.db.QueryContext(ctx, `
		SELECT fc.file_id, f.path, snippet(file_contents, 1, '>>>', '<<<', '...', 20)
		FROM file_contents fc
		JOIN files f ON f.id = fc.file_id
		WHERE file_contents MATCH ?
		ORDER BY rank
		LIMIT ?
	`, query, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var results []SearchResult
	for rows.Next() {
		var r SearchResult
		if err := rows.Scan(&r.FileID, &r.Path, &r.Snippet); err != nil {
			return nil, err
		}
		results = append(results, r)
	}
	return results, rows.Err()
}