package storage

import (
	"bufio"
	"context"
	"encoding/json"
	"os"
	"strings"

	"git.tornberg.me/go-otel/internal/websocket"
	"github.com/natefinch/lumberjack"
)

type FileStore struct {
	logger *lumberjack.Logger
}

func NewFileStore(filename string) *FileStore {
	return &FileStore{
		logger: &lumberjack.Logger{
			Filename:   filename,
			MaxSize:    100, // megabytes
			MaxBackups: 3,
			MaxAge:     28,   // days
			Compress:   true, // disabled by default
		},
	}
}

func (fs *FileStore) Append(ctx context.Context, entry websocket.HistoryEntry) error {
	data, err := json.Marshal(entry)
	if err != nil {
		return err
	}
	_, err = fs.logger.Write(append(data, '\n'))
	return err
}

func (fs *FileStore) GetHistory(ctx context.Context, limit int) ([]websocket.HistoryEntry, error) {
	return fs.Search(ctx, "", limit)
}

func (fs *FileStore) Search(ctx context.Context, query string, limit int) ([]websocket.HistoryEntry, error) {
	if limit <= 0 {
		limit = 50 // Default to a manageable number
	}

	file, err := os.Open(fs.logger.Filename)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil // No logs yet
		}
		return nil, err
	}
	defer file.Close()

	var matchingLines []string
	scanner := bufio.NewScanner(file)
	// Lowercase query for case-insensitive search
	lowerQuery := strings.ToLower(query)

	for scanner.Scan() {
		line := scanner.Text()
		if query == "" || strings.Contains(strings.ToLower(line), lowerQuery) {
			matchingLines = append(matchingLines, line)
			// Only keep the most recent 'limit' matches to save memory
			if len(matchingLines) > limit {
				matchingLines = matchingLines[1:]
			}
		}
	}

	var results []websocket.HistoryEntry
	// Reverse to get latest first (since matchingLines contains them in chronological order)
	for i := len(matchingLines) - 1; i >= 0; i-- {
		var entry websocket.HistoryEntry
		if err := json.Unmarshal([]byte(matchingLines[i]), &entry); err == nil {
			results = append(results, entry)
		}
	}

	return results, scanner.Err()
}