package main

import (
	"encoding/json"
	"fmt"
	"os"
	"sync"
	"time"
)

type LogWriter struct {
	file       *os.File
	mu         sync.Mutex
	errorsOnly bool
}

func NewLogWriter(path string, errorsOnly bool) (*LogWriter, error) {
	f, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		return nil, err
	}
	return &LogWriter{file: f, errorsOnly: errorsOnly}, nil
}

func (lw *LogWriter) Write(line string, isError bool) {
	if lw.errorsOnly && !isError {
		return
	}
	lw.mu.Lock()
	defer lw.mu.Unlock()
	fmt.Fprintln(lw.file, line)
}

func (lw *LogWriter) Close() error {
	return lw.file.Close()
}

func formatLogLine(icon IconRow, result DownloadResult) string {
	if result.Err != "" {
		return fmt.Sprintf("icon: %s err:%s %s", icon.URL, result.ErrType, result.Err)
	}

	dedup := ""
	if result.Dedup {
		dedup = " dedup"
	}

	dims := ""
	if result.Width > 0 && result.Height > 0 {
		dims = fmt.Sprintf(" %dx%d", result.Width, result.Height)
	}

	return fmt.Sprintf("icon: %s %s%s %.1fKB%s ok",
		icon.URL, result.ContentType, dims,
		float64(result.FileSize)/1024, dedup)
}

func writeStats(stats *Stats) {
	finishedAt := time.Now()
	duration := finishedAt.Sub(stats.StartedAt)

	data := map[string]interface{}{
		"started_at":       stats.StartedAt.Format(time.RFC3339),
		"finished_at":      finishedAt.Format(time.RFC3339),
		"duration_seconds": int(duration.Seconds()),
		"processed":        stats.Processed.Load(),
		"completed":        stats.Completed.Load(),
		"failed":           stats.Failed.Load(),
		"failed_dns":       stats.DNSErrors.Load(),
		"failed_timeout":   stats.Timeouts.Load(),
		"failed_http":      stats.HTTPErrors.Load(),
		"failed_invalid":   stats.InvalidImg.Load(),
		"failed_too_large": stats.TooLarge.Load(),
		"dedup_hits":       stats.DedupHits.Load(),
		"db_errors":        stats.DBErrors.Load(),
		"panics":           stats.Panics.Load(),
		"bytes_downloaded":  stats.BytesDown.Load(),
	}

	os.MkdirAll("stats", 0755)
	f, err := os.Create("stats/03_icon_download.json")
	if err != nil {
		fmt.Printf("Failed to write stats: %v\n", err)
		return
	}
	defer f.Close()

	enc := json.NewEncoder(f)
	enc.SetIndent("", "  ")
	enc.Encode(data)
	fmt.Println("Stats written to stats/03_icon_download.json")
}