package web

import (
	"encoding/csv"
	"fmt"
	"net"
	"net/http"
	"strconv"
	"strings"
	"time"

	"daili/internal/domain"
	"daili/internal/store"
)

type logsData struct {
	List  []store.OpLog
	Pager Pager
	Q     string
	Total int
}

func (s *Server) handleLogs(w http.ResponseWriter, r *http.Request) {
	q := r.URL.Query().Get("q")
	pageNo := s.queryInt(r, "page", 1)
	if pageNo < 1 {
		pageNo = 1
	}
	list, total, err := s.db.ListLogs(q, pageSize, (pageNo-1)*pageSize)
	if err != nil {
		http.Error(w, "读取日志失败", http.StatusInternalServerError)
		return
	}
	pager := newPager(r, pageNo, pageSize, total)
	if pager.Page != pageNo {
		list, total, err = s.db.ListLogs(q, pageSize, (pager.Page-1)*pageSize)
		if err != nil {
			http.Error(w, "读取日志失败", http.StatusInternalServerError)
			return
		}
	}
	p := s.newPage(r, "操作日志", "logs")
	p.D = &logsData{List: list, Pager: pager, Q: q, Total: total}
	s.render(w, r, "logs", p)
}

type settingsData struct {
	WarnDays      int
	Backups       []string
	DBPath        string
	BackupDir     string
	BackupKeep    int
	BackupEnabled bool
	ConfigPath    string
	Addrs         []string
	Port          string
	Uptime        string
	LogCount      int
	Version       string
	CustomerCount int
	PackageCount  int
}

func humanDuration(d time.Duration) string {
	secs := int(d.Seconds())
	days := secs / 86400
	hours := (secs % 86400) / 3600
	mins := (secs % 3600) / 60
	switch {
	case days > 0:
		return fmt.Sprintf("%d 天 %d 小时", days, hours)
	case hours > 0:
		return fmt.Sprintf("%d 小时 %d 分钟", hours, mins)
	default:
		return fmt.Sprintf("%d 分钟", mins)
	}
}

func LocalAddrs() []string {
	out := []string{}
	ifaces, err := net.Interfaces()
	if err != nil {
		return out
	}
	for _, iface := range ifaces {
		if iface.Flags&net.FlagUp == 0 || iface.Flags&net.FlagLoopback != 0 {
			continue
		}
		addrs, err := iface.Addrs()
		if err != nil {
			continue
		}
		for _, a := range addrs {
			var ip net.IP
			switch v := a.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}
			if ip == nil {
				continue
			}
			ip4 := ip.To4()
			if ip4 == nil || ip4.IsLoopback() {
				continue
			}
			ipStr := ip4.String()
			if strings.HasPrefix(ipStr, "169.254.") {
				continue
			}
			out = append(out, ipStr)
		}
	}
	return out
}

func (s *Server) handleSettings(w http.ResponseWriter, r *http.Request) {
	backups, _ := s.db.ListBackups()
	custN, _ := s.db.CustomerCount()
	pkgs, _ := s.db.ListPackages(true)
	logN, _ := s.db.LogCount()
	port := s.cfg.Addr
	if strings.HasPrefix(port, ":") {
		port = port[1:]
	}
	data := &settingsData{
		WarnDays:      s.warnDays(),
		Backups:       backups,
		DBPath:        s.db.Path,
		BackupDir:     s.cfg.BackupDir,
		BackupKeep:    s.cfg.BackupKeep,
		BackupEnabled: s.cfg.BackupEnabled,
		ConfigPath:    s.cfg.ConfigPath,
		Addrs:         LocalAddrs(),
		Port:          port,
		Uptime:        humanDuration(time.Since(s.started)),
		LogCount:      logN,
		Version:       s.cfg.Version,
		CustomerCount: custN,
		PackageCount:  len(pkgs),
	}
	p := s.newPage(r, "设置", "settings")
	p.D = data
	s.render(w, r, "settings", p)
}

func (s *Server) handleSettingsSave(w http.ResponseWriter, r *http.Request) {
	warn := s.formInt(r, "warn_days", 3)
	if warn < 0 {
		warn = 0
	}
	if warn > 60 {
		warn = 60
	}
	_ = s.db.SetSetting("warn_days", strconv.Itoa(warn))
	s.logOp(r, "修改设置", "settings", 0, fmt.Sprintf("预警 %d 天", warn))
	s.redirect(w, r, "/settings", "设置已保存")
}

func (s *Server) handlePasswordChange(w http.ResponseWriter, r *http.Request) {
	u := s.currentUser(r)
	old := r.PostFormValue("old_password")
	pw := r.PostFormValue("password")
	pw2 := r.PostFormValue("password2")
	if u == nil {
		http.Redirect(w, r, "/login", http.StatusFound)
		return
	}
	if _, err := s.db.Authenticate(u.Username, old); err != nil {
		s.redirect(w, r, "/settings", "原密码不正确")
		return
	}
	if len(pw) < 6 {
		s.redirect(w, r, "/settings", "新密码至少 6 位")
		return
	}
	if pw != pw2 {
		s.redirect(w, r, "/settings", "两次输入的新密码不一致")
		return
	}
	if err := s.db.UpdatePassword(u.ID, pw); err != nil {
		s.redirect(w, r, "/settings", "修改失败："+err.Error())
		return
	}
	s.logOp(r, "修改密码", "user", u.ID, "管理员 "+u.Username+" 修改了自己的密码")
	s.redirect(w, r, "/settings", "密码已更新")
}

func (s *Server) handleBackupNow(w http.ResponseWriter, r *http.Request) {
	path, err := s.db.BackupNow(s.cfg.BackupKeep)
	if err != nil {
		s.redirect(w, r, "/settings", "备份失败："+err.Error())
		return
	}
	s.logOp(r, "备份数据", "backup", 0, "手动备份 "+path)
	s.redirect(w, r, "/settings", "已备份："+path)
}

func (s *Server) handleExport(w http.ResponseWriter, r *http.Request) {
	kind := strings.TrimSuffix(r.PathValue("kind"), ".csv")
	var set *store.ExportRowSet
	var err error
	switch kind {
	case "customers":
		set, err = s.db.ExportCustomers()
	case "subscriptions":
		set, err = s.db.ExportSubscriptions(domain.Today(), s.warnDays())
	case "logs":
		set, err = s.db.ExportLogs()
	default:
		http.NotFound(w, r)
		return
	}
	if err != nil {
		http.Error(w, "导出失败："+err.Error(), http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "text/csv; charset=utf-8")
	w.Header().Set("Content-Disposition",
		fmt.Sprintf("attachment; filename=\"daili-%s-%s.csv\"", kind, time.Now().Format("20060102")))
	_, _ = w.Write([]byte{0xEF, 0xBB, 0xBF})
	cw := csv.NewWriter(w)
	_ = cw.Write(set.Header)
	for _, row := range set.Rows {
		_ = cw.Write(row)
	}
	cw.Flush()
	s.logOp(r, "导出数据", "export", 0, "导出 "+kind+"（"+strconv.Itoa(len(set.Rows))+" 行）")
}