package main

import (
	"context"
	"fmt"
	"os"
	"sync"
	"time"

	"github.com/golang/freetype/truetype"

	"douyu_go/internal/client"
	"douyu_go/internal/config"
	"douyu_go/internal/constants"
	imgpkg "douyu_go/internal/image"
	"douyu_go/internal/logger"
	"douyu_go/internal/seckill"
	"douyu_go/internal/trace"
	"douyu_go/internal/types"
)

// App 应用主结构体，所有导出方法可被前端通过 Wails 绑定调用。
type App struct {
	ctx context.Context

	client    *client.DouyuClient
	scheduler *seckill.Scheduler
	logStore  *logger.MemoryLogStore
	trace     *trace.Recorder
	paths     types.AppPaths
	font      *truetype.Font
	cfg       types.Config

	productsMu sync.RWMutex
	products   []types.Product
	productsAt time.Time

	closeLog   func()
	closeTrace func()
}

// NewApp 创建 App 实例。
func NewApp() *App {
	return &App{}
}

// startup Wails 应用启动时调用。
func (a *App) startup(ctx context.Context) {
	a.ctx = ctx

	a.paths = config.DefaultAppPaths()
	a.logStore = logger.NewMemoryLogStore(800)
	a.closeLog = logger.InitLogging(a.logStore, a.paths.LogDir)

	// 加载配置并应用运行时设置
	a.cfg = config.LoadConfig(a.paths.ConfigFile)
	logger.SetMinLevel(a.cfg.LogLevel)

	traceCfg := types.TraceConfig{
		Enabled:      a.cfg.TraceEnabled,
		MaxBodyBytes: a.cfg.TraceMaxBody,
	}
	tr, closeTrace := trace.InitTrace(a.paths.LogDir, traceCfg)
	a.trace = tr
	a.closeTrace = closeTrace

	a.client = client.New(a.cfg.TimeAPIURL, a.trace)
	a.font = imgpkg.LoadFont(a.paths.FontFiles)
	a.scheduler = seckill.New(a.client, a.paths, a.font, a.cfg.Concurrency, a.cfg.Attempts)
	a.scheduler.LoadAccounts()

	if err := os.MkdirAll(a.paths.SuccessDir, 0755); err != nil {
		logger.LogEvent("图片", "warn", "成功图片目录创建失败，图片保存功能可能不可用: %v", err)
	}

	if serverTime, err := a.client.ServerTime(); err == nil {
		logger.LogEvent("时间", "success", "服务端时间获取成功: %s", serverTime.In(constants.CST).Format("2006-01-02 15:04:05.000"))
	} else {
		logger.LogEvent("时间", "error", "服务端时间获取失败: %v", err)
	}

	logger.LogEvent("系统", "success", "应用启动完成 | 账号: %d", a.scheduler.AccountCount())
}

// shutdown Wails 应用关闭时调用。
func (a *App) shutdown(ctx context.Context) {
	if a.closeTrace != nil {
		a.closeTrace()
	}
	if a.closeLog != nil {
		a.closeLog()
	}
}

// ==================== 前端可调用方法 ====================

// LoadProducts 刷新商品列表。refresh=true 时从斗鱼实时拉取。
func (a *App) LoadProducts(refresh bool) types.ProductPayload {
	if refresh {
		products, err := a.client.Products()
		if err != nil {
			logger.LogEvent("商品", "error", "商品刷新失败: %v", err)
			return types.ProductPayload{Success: false}
		}
		fetchedAt := time.Now()
		a.setProducts(products, fetchedAt)
		logger.LogEvent("商品", "success", "商品刷新完成: %d 个，刷新时间=%s", len(products), fetchedAt.In(constants.CST).Format("15:04:05.000"))
		return a.productPayload("live")
	}
	return a.productPayload("cache")
}

// GetAccounts 返回账号列表。
func (a *App) GetAccounts() []types.AccountView {
	accounts := a.scheduler.AccountSnapshot()
	list := make([]types.AccountView, 0, len(accounts))
	for i, account := range accounts {
		list = append(list, types.AccountView{
			Index:  i,
			Name:   account.Name,
			Cookie: maskCookie(account.Cookie),
		})
	}
	return list
}

// ReloadAccounts 重新加载账号文件。
func (a *App) ReloadAccounts() map[string]any {
	a.scheduler.LoadAccounts()
	return map[string]any{"success": true, "count": a.scheduler.AccountCount()}
}

// StartSeckill 立即启动抢购。
func (a *App) StartSeckill(accountProducts map[string]string) map[string]any {
	if len(accountProducts) == 0 {
		return map[string]any{"success": false, "error": "请选择账号和商品"}
	}
	if !a.scheduler.TryStartRun() {
		return map[string]any{"success": false, "error": "抢购任务正在运行，请勿重复提交"}
	}
	go a.scheduler.RunNow(cloneMap(accountProducts))
	return map[string]any{"success": true, "msg": "抢购已启动"}
}

// SetSchedule 设置定时抢购。
func (a *App) SetSchedule(req types.SeckillRequest) (map[string]any, error) {
	return a.scheduler.ScheduleRun(req)
}

// CancelSchedule 取消未触发的定时抢购。
func (a *App) CancelSchedule() map[string]any {
	stopped := a.scheduler.CancelSchedule()
	return map[string]any{"success": true, "stopped": stopped}
}

// GetResults 返回当前抢购结果。
func (a *App) GetResults() map[string]string {
	return a.scheduler.Results()
}

// GetLogs 返回后端内存日志，支持增量获取。
func (a *App) GetLogs(since int64) map[string]any {
	entries := a.logStore.Since(since)
	nextSince := since
	if len(entries) > 0 {
		nextSince = entries[len(entries)-1].ID
	}
	return map[string]any{
		"success": true,
		"logs":    entries,
		"since":   nextSince,
		"file":    a.logStore.FilePath(),
	}
}

// GetTime 返回服务端时间和本地时间。
func (a *App) GetTime() map[string]any {
	serverTime, err := a.client.ServerTime()
	source := "currentTime"
	if err != nil {
		source = "localFallback"
		logger.LogEvent("时间", "warn", "时间接口降级: %v", err)
	}
	return map[string]any{
		"serverTime": serverTime.In(constants.CST).Format("2006-01-02 15:04:05.000"),
		"localTime":  time.Now().In(constants.CST).Format("2006-01-02 15:04:05.000"),
		"source":     source,
	}
}

// ClearResults 清空抢购结果。
func (a *App) ClearResults() map[string]any {
	a.scheduler.ClearResults()
	return map[string]any{"success": true}
}

// QueryScore 查询单个账号的积分。
func (a *App) QueryScore(accountName string) map[string]any {
	if accountName == "" {
		return map[string]any{"score": "缺少账号名"}
	}
	cookie, ok := a.scheduler.AccountCookieByName(accountName)
	if !ok || cookie == "" {
		return map[string]any{"score": fmt.Sprintf("账号不存在或 Cookie 为空: %s", accountName)}
	}
	score, err := a.client.Score(cookie)
	if err != nil {
		return map[string]any{"score": "查询失败: " + err.Error()}
	}
	return map[string]any{"score": score}
}

// VerifyExchange 查询兑换记录，用于复验抢购结果。
func (a *App) VerifyExchange(accountName string) map[string]any {
	if accountName == "" {
		return map[string]any{"success": false, "error": "缺少账号名"}
	}
	cookie, ok := a.scheduler.AccountCookieByName(accountName)
	if !ok || cookie == "" {
		return map[string]any{"success": false, "error": fmt.Sprintf("账号不存在或 Cookie 为空: %s", accountName)}
	}

	records, err := a.client.ExchangeList(cookie)
	if err != nil {
		return map[string]any{"success": false, "error": "查询失败: " + err.Error()}
	}

	// 过滤当前活动的记录
	var matched []client.ExchangeRecord
	for _, r := range records {
		if r.CommodityID != "" {
			matched = append(matched, r)
		}
	}

	return map[string]any{
		"success": true,
		"records": matched,
		"count":   len(matched),
	}
}

// GetVersion 返回应用版本号。
func (a *App) GetVersion() string {
	return constants.Version
}

// GetSettings 返回当前配置。
func (a *App) GetSettings() types.Config {
	return a.cfg
}

// SaveSettings 保存配置并运行时生效。
func (a *App) SaveSettings(cfg types.Config) map[string]any {
	// 校验
	if cfg.Concurrency <= 0 {
		cfg.Concurrency = constants.DefaultConcurrency
	}
	if cfg.Attempts <= 0 {
		cfg.Attempts = constants.DefaultAttempts
	}
	if cfg.LogLevel == "" {
		cfg.LogLevel = "info"
	}

	// 写入文件
	if err := config.SaveConfig(a.paths.ConfigFile, cfg); err != nil {
		logger.LogEvent("配置", "error", "配置保存失败: %v", err)
		return map[string]any{"success": false, "error": err.Error()}
	}

	// 运行时生效
	a.cfg = cfg
	logger.SetMinLevel(cfg.LogLevel)
	a.scheduler.UpdateSettings(cfg.Concurrency, cfg.Attempts)

	logger.LogEvent("配置", "success", "配置已保存并生效: 日志等级=%s 并发=%d 重试=%d trace=%v",
		cfg.LogLevel, cfg.Concurrency, cfg.Attempts, cfg.TraceEnabled)
	return map[string]any{"success": true}
}

// ==================== 内部辅助方法 ====================

func (a *App) setProducts(products []types.Product, fetchedAt time.Time) {
	a.productsMu.Lock()
	defer a.productsMu.Unlock()
	a.products = products
	a.productsAt = fetchedAt
}

func (a *App) productPayload(source string) types.ProductPayload {
	a.productsMu.RLock()
	defer a.productsMu.RUnlock()

	payload := types.ProductPayload{
		Success:  true,
		Source:   source,
		Products: a.products,
		Count:    len(a.products),
	}
	if !a.productsAt.IsZero() {
		age := time.Since(a.productsAt)
		if age < 0 {
			age = 0
		}
		payload.FetchedAt = a.productsAt.In(constants.CST).Format("2006-01-02 15:04:05.000")
		payload.AgeSecond = int(age.Seconds())
		payload.Stale = age > constants.ProductCacheTTL
	} else {
		payload.Stale = true
	}
	return payload
}

func cloneMap(in map[string]string) map[string]string {
	out := make(map[string]string, len(in))
	for k, v := range in {
		out[k] = v
	}
	return out
}

func maskCookie(cookie string) string {
	pairs := splitCookie(cookie)
	masked := make([]string, 0, 3)
	total := 0
	for _, pair := range pairs {
		key, value := splitCookiePair(pair)
		if key == "" {
			continue
		}
		total++
		if len(masked) >= 3 {
			continue
		}
		masked = append(masked, key+"="+maskValue(value))
	}
	if total == 0 {
		return ""
	}
	if total > len(masked) {
		masked = append(masked, fmt.Sprintf("...共%d项", total))
	}
	return joinStrings(masked, "; ")
}

func splitCookie(cookie string) []string {
	var result []string
	for _, part := range splitString(cookie, ";") {
		trimmed := trimSpace(part)
		if trimmed != "" {
			result = append(result, trimmed)
		}
	}
	return result
}

func splitCookiePair(pair string) (string, string) {
	idx := indexOf(pair, "=")
	if idx < 0 {
		return trimSpace(pair), ""
	}
	return trimSpace(pair[:idx]), pair[idx+1:]
}

func maskValue(value string) string {
	value = trimSpace(value)
	if value == "" {
		return "****"
	}
	runes := []rune(value)
	if len(runes) <= 8 {
		return "****"
	}
	return string(runes[:4]) + "****" + string(runes[len(runes)-4:])
}

// 简单的字符串工具函数，避免引入额外包
func splitString(s, sep string) []string {
	var result []string
	start := 0
	for i := 0; i+len(sep) <= len(s); {
		if s[i:i+len(sep)] == sep {
			result = append(result, s[start:i])
			start = i + len(sep)
			i = start
		} else {
			i++
		}
	}
	result = append(result, s[start:])
	return result
}

func trimSpace(s string) string {
	for len(s) > 0 && (s[0] == ' ' || s[0] == '\t' || s[0] == '\n' || s[0] == '\r') {
		s = s[1:]
	}
	for len(s) > 0 && (s[len(s)-1] == ' ' || s[len(s)-1] == '\t' || s[len(s)-1] == '\n' || s[len(s)-1] == '\r') {
		s = s[:len(s)-1]
	}
	return s
}

func indexOf(s, sub string) int {
	for i := 0; i+len(sub) <= len(s); i++ {
		if s[i:i+len(sub)] == sub {
			return i
		}
	}
	return -1
}

func joinStrings(parts []string, sep string) string {
	if len(parts) == 0 {
		return ""
	}
	result := parts[0]
	for _, p := range parts[1:] {
		result += sep + p
	}
	return result
}