package utils

import (
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/wailsapp/wails/v2/pkg/logger"
)

// multiLogger fans every log call out to multiple logger.Logger targets with timestamps.
type multiLogger struct {
	targets []logger.Logger
}

// timestamped prefixes each message with a timestamp.
func timestamped(message string) string {
	return time.Now().Format("2006-01-02 15:04:05") + " " + message
}

func (m *multiLogger) Print(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Print(msg)
	}
}
func (m *multiLogger) Trace(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Trace(msg)
	}
}
func (m *multiLogger) Debug(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Debug(msg)
	}
}
func (m *multiLogger) Info(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Info(msg)
	}
}
func (m *multiLogger) Warning(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Warning(msg)
	}
}
func (m *multiLogger) Error(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Error(msg)
	}
}
func (m *multiLogger) Fatal(message string) {
	msg := timestamped(message)
	for _, l := range m.targets {
		l.Fatal(msg)
	}
}

// NewRuntimeFileLogger returns a logger that writes all output both to
//
//	$XDG_CONFIG_HOME/FanslySync/logs/runtime_latest.log (or OS equivalent)
//
// and to a timestamped file
//
//	$XDG_CONFIG_HOME/FanslySync/logs/runtime_YYYY-MM-DD_HH-MM-SS.log (or OS equivalent)
//
// It also deletes any timestamped logs older than 14 days.
//
// The returned logger implements github.com/wailsapp/wails/v2/pkg/logger.Logger
// and will be used by Wails for all Go-side logging.
func NewRuntimeFileLogger() (logger.Logger, error) {
	// Make sure the log directory exists
	// We use $XDG_CONFIG_HOME/FanslySync/logs/runtime_latest.log or OS equivalent for $XDG_CONFIG_HOME
	cfgDir, err := os.UserConfigDir()
	if err != nil {
		return nil, fmt.Errorf("cannot determine user config dir: %w", err)
	}
	logDir := filepath.Join(cfgDir, "FanslySync", "logs")
	if err := os.MkdirAll(logDir, 0o755); err != nil {
		return nil, fmt.Errorf("cannot create log directory: %w", err)
	}

	// Prune old logs
	// We keep logs for 14 days, so delete any logs older than that
	cutoff := time.Now().Add(-14 * 24 * time.Hour)
	entries, _ := os.ReadDir(logDir)
	for _, e := range entries {
		if e.IsDir() || e.Name() == "runtime_latest.log" {
			continue
		}
		info, err := e.Info()
		if err != nil {
			continue
		}
		if info.ModTime().Before(cutoff) {
			_ = os.Remove(filepath.Join(logDir, e.Name()))
		}
	}

	ts := time.Now().Format("2006-01-02_15-04-05")
	tsPath := filepath.Join(logDir, fmt.Sprintf("runtime_%s.log", ts))
	latestPath := filepath.Join(logDir, "runtime_latest.log")

	// Create loggers to attach to the multiLogger
	tsLogger := logger.NewFileLogger(tsPath)
	latestLogger := logger.NewFileLogger(latestPath)
	termLogger := logger.NewDefaultLogger()

	// Spread into a multiLogger
	// This will fan out all log messages to all three loggers
	multi := &multiLogger{
		targets: []logger.Logger{tsLogger, latestLogger, termLogger},
	}

	return multi, nil
}