package models

import (
	"arbeitszeitmessung/helper"
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"strconv"
	"time"
)

type WorkDay struct {
	Day       time.Time `json:"day"`
	Bookings  []Booking `json:"bookings"`
	workTime  time.Duration
	pauseTime time.Duration
	TimeFrom  time.Time
	TimeTo    time.Time
	Absence   Absence
}

func (d *WorkDay) GetWorkDays(card_uid string, tsFrom, tsTo time.Time) []WorkDay {
	var workDays []WorkDay
	var workSec, pauseSec float64

	qStr, err := DB.Prepare(`
	WITH all_days AS (
    SELECT generate_series($2, $3, INTERVAL '1 day')::DATE AS work_date
    ),
    ordered_bookings AS (
        SELECT
            timestamp::DATE AS work_date,
            timestamp,
            check_in_out,
            counter_id,
            LAG(timestamp) OVER (PARTITION BY card_uid, timestamp::DATE ORDER BY timestamp) AS prev_timestamp,
            LAG(check_in_out) OVER (PARTITION BY card_uid, timestamp::DATE ORDER BY timestamp) AS prev_check
        FROM anwesenheit
        WHERE card_uid = $1
        AND timestamp::DATE >= $2
        AND timestamp::DATE <= $3
    ),
    abwesenheiten AS (
        SELECT
            datum::DATE AS work_date,
            abwesenheit_typ
        FROM abwesenheit
        WHERE card_uid = $1
        AND datum::DATE >= $2
        AND datum::DATE <= $3
    )
    SELECT
        d.work_date,
        COALESCE(MIN(b.timestamp), NOW()) AS time_from,
        COALESCE(MAX(b.timestamp), NOW()) AS time_to,
        COALESCE(
            EXTRACT(EPOCH FROM SUM(
                CASE
                    WHEN b.prev_check IN (1, 3) AND b.check_in_out IN (2, 4, 255)
                    THEN b.timestamp - b.prev_timestamp
                    ELSE INTERVAL '0'
                END
            )), 0
        ) AS total_work_seconds,
        COALESCE(
            EXTRACT(EPOCH FROM SUM(
                CASE
                    WHEN b.prev_check IN (2, 4, 255) AND b.check_in_out IN (1, 3)
                    THEN b.timestamp - b.prev_timestamp
                    ELSE INTERVAL '0'
                END
            )), 0
        ) AS total_pause_seconds,
        COALESCE(jsonb_agg(jsonb_build_object(
            'check_in_out', b.check_in_out,
            'timestamp', b.timestamp,
            'counter_id', b.counter_id
        ) ORDER BY b.timestamp), '[]'::jsonb) AS bookings,
        a.abwesenheit_typ
    FROM all_days d
    LEFT JOIN ordered_bookings b ON d.work_date = b.work_date
    LEFT JOIN abwesenheiten a ON d.work_date = a.work_date
    GROUP BY d.work_date, a.abwesenheit_typ
    ORDER BY d.work_date;`)

	if err != nil {
		log.Println("Error preparing SQL statement", err)
		return workDays
	}

	defer qStr.Close()
	rows, err := qStr.Query(card_uid, tsFrom, tsTo)
	if err != nil {
		log.Println("Error getting rows!")
		return workDays
	}
	defer rows.Close()
	emptyDays, _ := strconv.ParseBool(helper.GetEnv("EMPTY_DAYS", "false"))
	for rows.Next() {
		var workDay WorkDay
		var bookings []byte
		var absenceType sql.NullInt16
		if err := rows.Scan(&workDay.Day, &workDay.TimeFrom, &workDay.TimeTo, &workSec, &pauseSec, &bookings, &absenceType); err != nil {
			log.Println("Error scanning row!", err)
			return workDays
		}
		workDay.workTime = time.Duration(workSec * float64(time.Second))
		workDay.pauseTime = time.Duration(pauseSec * float64(time.Second))
		err = json.Unmarshal(bookings, &workDay.Bookings)
		if err != nil {
			log.Println("Error parsing bookings JSON!", err)
			return nil
		}
		// better empty day handling
		if len(workDay.Bookings) == 1 && workDay.Bookings[0].CounterId == 0 {
			workDay.Bookings = []Booking{}
		}

		if absenceType.Valid {
			workDay.Absence = NewAbsence(card_uid, int8(absenceType.Int16), workDay.Day)
			log.Println("Found absence", workDay.Absence)
		}

		if workDay.Day.Equal(time.Now().Truncate(24 * time.Hour)) {
			workDay.getWorkTime()
		} else {
			workDay.calcPauseTime()
		}
		if emptyDays || len(workDay.Bookings) > 0 || (workDay.Absence != Absence{}) {
			workDays = append(workDays, workDay)
		} else {
			log.Println("no booking on day", workDay.Day.Format("02.01.2006"))
		}
	}
	if err = rows.Err(); err != nil {
		return workDays
	}
	return workDays
}

func (d *WorkDay) calcPauseTime() {
	if d.workTime > 6*time.Hour && d.pauseTime < 45*time.Minute {
		if d.workTime < 9*time.Hour && d.pauseTime < 30*time.Minute {
			diff := 30*time.Minute - d.pauseTime
			d.workTime -= diff
			d.pauseTime += diff
		} else if d.pauseTime < 45*time.Minute {
			diff := 45*time.Minute - d.pauseTime
			d.workTime -= diff
			d.pauseTime += diff
		}
	}
}

// Gets the duration someone worked that day
func (d *WorkDay) getWorkTime() {
	if len(d.Bookings) <= 1 && d.Bookings[0].CounterId == 0 {
		return
	}
	var workTime, pauseTime time.Duration
	var lastBooking Booking
	for _, booking := range d.Bookings {
		if booking.CheckInOut%2 == 1 {
			if !lastBooking.Timestamp.IsZero() {
				pauseTime += booking.Timestamp.Sub(lastBooking.Timestamp)
			}
		} else {
			workTime += booking.Timestamp.Sub(lastBooking.Timestamp)
		}
		lastBooking = booking
	}
	// checks if booking is today and has no gehen yet, so the time since last kommen booking is added to workTime
	if d.Day.Day() == time.Now().Day() && len(d.Bookings)%2 == 1 {
		workTime += time.Since(lastBooking.Timestamp.Local())
	}
	d.workTime = workTime
	d.pauseTime = pauseTime

	d.calcPauseTime()
}

// Converts duration to string
func formatDuration(d time.Duration) string {
	hours := int(d.Abs().Hours())
	minutes := int(d.Abs().Minutes()) % 60
	switch {
	case hours > 0:
		return fmt.Sprintf("%dh %dmin", hours, minutes)
	case minutes > 0:
		return fmt.Sprintf("%dmin", minutes)
	default:
		return ""
	}
}

func (d *WorkDay) GetWorkTimeString() (string, string) {
	workString := formatDuration(d.workTime)
	pauseString := formatDuration(d.pauseTime)
	return workString, pauseString
}

// returns bool wheter the workday was ended with an automatic logout
func (d *WorkDay) RequiresAction() bool {
	if len(d.Bookings) > 0 {
		return d.Bookings[len(d.Bookings)-1].CheckInOut == 254
	}
	return false
}

// returns a integer percentage of how much day has been worked of
func (d *WorkDay) GetWorkDayProgress(user User) uint8 {
	defaultWorkTime := time.Duration(user.ArbeitszeitPerTag * float32(time.Hour))
	progress := (d.workTime.Seconds() / defaultWorkTime.Seconds()) * 100
	return uint8(progress)
}