package bot

import (
	"context"
	"fmt"
	"log/slog"
	"time"

	bot "github.com/go-telegram/bot"

	"worktimeBot/internal/db"
)

// buildStatusText returns the main menu status text for the current user.
func (h *Handler) buildStatusText(chatID int64) string {
	user, day, err := h.getUserToday(chatID)
	if err != nil {
		return "Welcome. Choose an action:"
	}

	text := fmt.Sprintf("Today: %s", formatDateForCalendar(day.Date, user.Calendar))

	if day.IsDayOff {
		text += "\nDay Off"
	}

	wt, _ := h.DB.GetWorkType(day.CurrentWorkTypeID)
	if wt != nil {
		text += fmt.Sprintf("\nWork type: %s", wt.Name)
	}

	last, err := h.DB.GetLastEvent(user.ID)
	if err == nil && last != nil && last.EventType == "in" {
		loc := loadLocation(user.Timezone)
		t := time.Unix(last.OccurredAt, 0).In(loc).Format("15:04")
		text += fmt.Sprintf("\nStatus: working since %s", t)
	} else {
		text += "\nStatus: not working"
	}

	events, err := h.DB.EventsForDayByDayID(day.ID)
	if err == nil && len(events) > 0 {
		loc := loadLocation(user.Timezone)
		now := time.Now().In(loc)
		y, m, d := now.Date()
		dayStart := time.Date(y, m, d, 0, 0, 0, 0, loc).Unix()
		dayEnd := now.Unix()
		totals := ComputeDailyTotals(events, day.MinBreakThreshold, dayStart, dayEnd)
		text += fmt.Sprintf("\nToday: %s worked", formatDuration(totals.TotalSeconds))
	}

	text += "\n\nChoose an action:"
	return text
}

// backToMenu returns to the main menu from any sub-menu.
func (h *Handler) backToMenu(ctx context.Context, chatID int64, msgID int, callbackID string) {
	defer h.answerCb(ctx, callbackID)
	kb := mainKeyboard()
	h.editText(ctx, chatID, msgID, h.buildStatusText(chatID), &kb)
}

// buildDailyReport builds a formatted daily report string for a given user/day.
func (h *Handler) buildDailyReport(user *db.User, day *db.Day, events []db.Event) string {
	loc, err := time.LoadLocation(user.Timezone)
	if err != nil {
		loc = time.UTC
	}

	if len(events) == 0 {
		if day.IsDayOff {
			return fmt.Sprintf("%s - Day Off", formatDateForCalendar(day.Date, user.Calendar))
		}
		return fmt.Sprintf("%s - No events recorded.", formatDateForCalendar(day.Date, user.Calendar))
	}

	y, m, d := parseGregorianDateKey(day.Date)
	dayStart := time.Date(y, time.Month(m), d, 0, 0, 0, 0, loc).Unix()
	now := time.Now().In(loc)
	todayStr := now.Format("2006-01-02")
	dayEnd := time.Date(y, time.Month(m), d, 23, 59, 59, 0, loc).Unix()
	if day.Date == todayStr {
		dayEnd = now.Unix()
	}
	totals := ComputeDailyTotals(events, day.MinBreakThreshold, dayStart, dayEnd)

	lines := fmt.Sprintf("Report for %s", formatDateForCalendar(day.Date, user.Calendar))
	if day.IsDayOff {
		lines += "\nDay Off: Yes"
	}
	lines += "\n\n"

	for _, e := range events {
		t := time.Unix(e.OccurredAt, 0).In(loc).Format("15:04")
		label := "IN"
		if e.EventType == "out" {
			label = "OUT"
		}
		suffix := ""
		if e.WorkTypeID != nil {
			if wtObj, err := h.DB.GetWorkType(*e.WorkTypeID); err == nil {
				suffix = " [" + wtObj.Name + "]"
			}
		}
		if e.Note != "" {
			suffix += " (" + e.Note + ")"
		}
		lines += fmt.Sprintf("%s %s%s\n", label, t, suffix)
	}

	lines += fmt.Sprintf("\nSummary:\n  Work: %s\n  Break: %s\n",
		formatDuration(totals.TotalSeconds),
		formatDuration(totals.BreakSeconds))

	return lines
}

// SendDailyReport sends the automated daily report to the user.
func (h *Handler) SendDailyReport(ctx context.Context, userID int64, chatID int64) {
	user, err := h.DB.GetUserByChatID(chatID)
	if err != nil {
		slog.Error("daily report: user not found", "user_id", userID)
		return
	}
	loc, err := time.LoadLocation(user.Timezone)
	if err != nil {
		loc = time.UTC
	}
	now := time.Now().In(loc)
	today := now.Format("2006-01-02")

	day, err := h.DB.GetOrCreateDay(user.ID, today)
	if err != nil {
		slog.Error("daily report: get day", "error", err)
		return
	}
	events, err := h.DB.EventsForDayByDayID(day.ID)
	if err != nil {
		slog.Error("daily report: get events", "error", err)
		return
	}
	text := h.buildDailyReport(user, day, events)
	_, err = h.Bot.SendMessage(ctx, &bot.SendMessageParams{ChatID: chatID, Text: text})
	if err != nil {
		slog.Error("daily report: send message failed", "chat_id", chatID, "error", err)
		return
	}
	if err := h.DB.MarkReportSent(user.ID, today); err != nil {
		slog.Error("daily report: mark sent failed", "chat_id", chatID, "error", err)
	}
}