package main

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

	"hub.gaomia.site/titor/YunShu/pkg/style"
	"gopkg.in/yaml.v3"
)

type LogLevel string

const (
	LevelWarn  LogLevel = "warn"
	LevelError LogLevel = "error"
	LevelInfo  LogLevel = "info"
	LevelOK    LogLevel = "ok"
)

var logToStderr bool

type logEntry struct {
	Time   string         `yaml:"time"`
	Level  LogLevel       `yaml:"level"`
	Msg    string         `yaml:"msg"`
	Fields map[string]any `yaml:",inline,omitempty"`
}

func logPath() string {
	return filepath.Join(ConfigDir(), "log.yml")
}

func buildFields(keyvals []any) map[string]any {
	m := make(map[string]any)
	for i := 0; i < len(keyvals)-1; i += 2 {
		if key, ok := keyvals[i].(string); ok {
			m[key] = keyvals[i+1]
		}
	}
	return m
}

func appendLog(level LogLevel, msg string, keyvals ...any) {
	path := logPath()
	var entries []logEntry
	if data, err := os.ReadFile(path); err == nil && len(data) > 0 {
		yaml.Unmarshal(data, &entries)
	}
	if entries == nil {
		entries = make([]logEntry, 0)
	}

	entry := logEntry{
		Time:  time.Now().Format(time.RFC3339),
		Level: level,
		Msg:   msg,
	}
	if len(keyvals) > 0 {
		entry.Fields = buildFields(keyvals)
	}

	entries = append(entries, entry)

	out, err := yaml.Marshal(entries)
	if err != nil {
		return
	}
	os.WriteFile(path, out, 0644)
}

func readLogs() ([]logEntry, error) {
	data, err := os.ReadFile(logPath())
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, err
	}
	if len(strings.TrimSpace(string(data))) == 0 {
		return nil, nil
	}
	var entries []logEntry
	if err := yaml.Unmarshal(data, &entries); err != nil {
		return nil, err
	}
	return entries, nil
}

func clearLogs() {
	os.WriteFile(logPath(), []byte("[]\n"), 0644)
}

func levelColor(l LogLevel) *style.Style {
	switch l {
	case LevelWarn:
		return style.Yellow
	case LevelError:
		return style.Red
	case LevelInfo:
		return style.Cyan
	case LevelOK:
		return style.Green
	default:
		return style.Dim
	}
}

func displayLogs(entries []logEntry, filterLevel string, top int) {
	if len(entries) == 0 {
		fmt.Println(style.Dim.Render("（暂无日志）"))
		return
	}

	// 按时间倒序
	for i, j := 0, len(entries)-1; i < j; i, j = i+1, j-1 {
		entries[i], entries[j] = entries[j], entries[i]
	}

	// 筛选级别
	if filterLevel != "" {
		var filtered []logEntry
		for _, e := range entries {
			if string(e.Level) == filterLevel {
				filtered = append(filtered, e)
			}
		}
		entries = filtered
	}

	if top > 0 && top < len(entries) {
		entries = entries[:top]
	}

	for _, e := range entries {
		ls := levelColor(e.Level)
		label := ls.Render(fmt.Sprintf("[%-5s]", strings.ToUpper(string(e.Level))))
		timeStr := style.Dim.Render(e.Time)
		fmt.Printf("%s %s  %s\n", label, timeStr, e.Msg)
		for k, v := range e.Fields {
			fmt.Printf("                             %s = %v\n", style.Dim.Render(k), style.Dim.Render(fmt.Sprintf("%v", v)))
		}
	}
}

func followLogs(filterLevel string) {
	lastCount := 0
	first := true

	for {
		entries, err := readLogs()
		if err != nil {
			time.Sleep(2 * time.Second)
			continue
		}

		n := len(entries)
		if n == 0 {
			if first {
				fmt.Println(style.Dim.Render("等待新日志..."))
				first = false
			}
			time.Sleep(2 * time.Second)
			continue
		}

		if first {
			fmt.Println(style.Dim.Render("日志监听中... Ctrl+C 退出"))
			fmt.Println()
			lastCount = n
			first = false
			time.Sleep(2 * time.Second)
			continue
		}

		if n > lastCount {
			for _, e := range entries[lastCount:] {
				if filterLevel != "" && string(e.Level) != filterLevel {
					continue
				}
				ls := levelColor(e.Level)
				label := ls.Render(fmt.Sprintf("[%-5s]", strings.ToUpper(string(e.Level))))
				timeStr := style.Dim.Render(e.Time)
				fmt.Printf("%s %s  %s\n", label, timeStr, e.Msg)
				for k, v := range e.Fields {
					fmt.Printf("                             %s = %v\n", style.Dim.Render(k), style.Dim.Render(fmt.Sprintf("%v", v)))
				}
			}
		}
		lastCount = n

		time.Sleep(2 * time.Second)
	}
}

func runLogCmd(args []string) {
	fs := flag.NewFlagSet("log", flag.ExitOnError)
	top := fs.Int("top", 0, "显示最后 N 条日志")
	level := fs.String("level", "", "按级别过滤 (warn/error/info/ok)")
	clear := fs.Bool("clear", false, "清空日志文件")
	watch := fs.Bool("watch", false, "监听模式，实时输出新日志")
	fs.Parse(args)

	if *clear {
		if *top > 0 || *level != "" || *watch {
			fmt.Fprintln(os.Stderr, style.Red.Render("--clear 不能与其他选项组合"))
			os.Exit(1)
		}
		clearLogs()
		fmt.Println(style.Green.Render("日志已清空"))
		return
	}

	if *watch {
		followLogs(*level)
		return
	}

	entries, err := readLogs()
	if err != nil {
		fmt.Fprintln(os.Stderr, style.Red.Render("读取日志失败: "+err.Error()))
		os.Exit(1)
	}
	displayLogs(entries, *level, *top)
}

func warnLog(msg string, keyvals ...any) {
	if logToStderr {
		Log.Warn(msg, keyvals...)
	}
	appendLog(LevelWarn, msg, keyvals...)
}

func errorLog(msg string, keyvals ...any) {
	if logToStderr {
		Log.Error(msg, keyvals...)
	}
	appendLog(LevelError, msg, keyvals...)
}

func infoLog(msg string, keyvals ...any) {
	if logToStderr {
		Log.Info(msg, keyvals...)
	}
	appendLog(LevelInfo, msg, keyvals...)
}