package models

import (
	"database/sql"
	"errors"
	"log"
	"time"
)

// Workweeks are

type WorkWeek struct {
	Id           int
	WorkDays     []WorkDay
	Absences     []Absence
	Days         []IWorkDay
	User         User
	WeekStart    time.Time
	Worktime     time.Duration
	Overtime     time.Duration
	Status       WeekStatus
	overtimeDiff time.Duration
	worktimeDiff time.Duration
}

type WeekStatus int8

const (
	WeekStatusNone WeekStatus = iota
	WeekStatusSent
	WeekStatusAccepted
	WeekStatusDifferences
)

func NewWorkWeek(user User, tsMonday time.Time, populate bool) WorkWeek {
	var week WorkWeek = WorkWeek{
		User:      user,
		WeekStart: tsMonday,
		Status:    WeekStatusNone,
	}
	if populate {
		week.PopulateWithDays(0, 0)
	}
	return week
}

func (w *WorkWeek) PopulateWithDays(worktime time.Duration, overtime time.Duration) {
	w.Days = GetDays(w.User, w.WeekStart, w.WeekStart.Add(6*24*time.Hour), false)

	for _, day := range w.Days {
		w.Worktime += day.TimeWorkVirtual(w.User)
	}
	w.Overtime = w.Worktime - w.User.ArbeitszeitProWoche()

	w.Worktime = w.Worktime.Round(time.Minute)
	w.Overtime = w.Overtime.Round(time.Minute)

	if overtime == 0 && worktime == 0 {
		return
	}

	if overtime != w.Overtime || worktime != w.Worktime {
		w.Status = WeekStatusDifferences
		w.overtimeDiff = overtime
		w.worktimeDiff = worktime
	}
}

func (w *WorkWeek) CheckStatus() WeekStatus {
	if w.Status != WeekStatusNone {
		return w.Status
	}
	if DB == nil {
		log.Println("Cannot access Database!")
		return w.Status
	}
	qStr, err := DB.Prepare(`SELECT bestaetigt FROM wochen_report WHERE woche_start = $1::DATE AND personal_nummer = $2;`)
	if err != nil {
		log.Println("Error preparing SQL statement", err)
		return w.Status
	}
	defer qStr.Close()
	var beastatigt bool
	err = qStr.QueryRow(w.WeekStart, w.User.PersonalNummer).Scan(&beastatigt)
	if err == sql.ErrNoRows {
		return w.Status
	}
	if err != nil {
		log.Println("Error querying database", err)
		return w.Status
	}
	if beastatigt {
		w.Status = WeekStatusAccepted
	} else {
		w.Status = WeekStatusSent
	}
	return w.Status
}

func (w *WorkWeek) aggregateWorkTime() time.Duration {
	var workTime time.Duration
	for _, day := range w.WorkDays {
		workTime += day.workTime
	}
	// for _, absence := range w.Absences {
	// 	log.Println(absence)
	// 	absenceWorkTime := float32(8) // := absences.AbwesenheitTyp.WorkTime - (absences.AbwesenheitTyp.WorkTime - w.User.ArbeitszeitPerTag) // workTime Equivalent of Absence is capped at user Worktime per Day
	// 	workTime += time.Duration(absenceWorkTime * float32(time.Hour)).Round(time.Minute)
	// }
	return workTime
}

func (w *WorkWeek) GetSendWeeks(user User) []WorkWeek {
	var weeks []WorkWeek
	qStr, err := DB.Prepare(`SELECT id, woche_start::DATE, (EXTRACT(epoch FROM arbeitszeit)*1000000000)::BIGINT, (EXTRACT(epoch FROM ueberstunden)*1000000000)::BIGINT FROM wochen_report WHERE bestaetigt = FALSE AND personal_nummer = $1;`)
	if err != nil {
		log.Println("Error preparing SQL statement", err)
		return weeks
	}
	defer qStr.Close()

	rows, err := qStr.Query(user.PersonalNummer)
	if err != nil {
		log.Println("Error querining db!", err)
		return weeks
	}
	defer rows.Close()
	for rows.Next() {
		var week WorkWeek = WorkWeek{User: user}
		if err := rows.Scan(&week.Id, &week.WeekStart, &week.Worktime, &week.Overtime); err != nil {
			log.Println("Error scanning row!", err)
			return weeks
		}

		week.PopulateWithDays(week.Worktime, week.Overtime)
		weeks = append(weeks, week)
	}
	if err = rows.Err(); err != nil {
		return weeks
	}

	return weeks
}

var ErrRunningWeek = errors.New("Week is in running week")

// creates a new entry in the woche_report table with the given workweek
func (w *WorkWeek) SendWeek() error {
	var qStr *sql.Stmt
	var err error

	if time.Since(w.WeekStart) < 5*24*time.Hour {
		log.Println("Cannot send week, because it's the running week!")
		return ErrRunningWeek
	}

	if w.CheckStatus() != WeekStatusNone {
		qStr, err = DB.Prepare(`UPDATE "wochen_report" SET bestaetigt = FALSE, arbeitszeit = make_interval(secs => $3::numeric / 1000000000), ueberstunden = make_interval(secs => $4::numeric / 1000000000) WHERE personal_nummer = $1 AND woche_start = $2;`)
		if err != nil {
			log.Println("Error preparing SQL statement", err)
			return err
		}
	} else {
		qStr, err = DB.Prepare(`INSERT INTO wochen_report (personal_nummer, woche_start, arbeitszeit, ueberstunden) VALUES ($1, $2, make_interval(secs => $3::numeric / 1000000000), make_interval(secs => $4::numeric / 1000000000));`)
		if err != nil {
			log.Println("Error preparing SQL statement", err)
			return err
		}
	}
	_, err = qStr.Exec(w.User.PersonalNummer, w.WeekStart, int64(w.Worktime), int64(w.Overtime))
	if err != nil {
		log.Println("Error executing query!", err)
		return err
	}
	return nil
}

func (w *WorkWeek) Accept() error {
	qStr, err := DB.Prepare(`UPDATE "wochen_report" SET bestaetigt = TRUE WHERE personal_nummer = $1 AND woche_start = $2;`)
	if err != nil {
		log.Println("Error preparing SQL statement", err)
		return err
	}
	_, err = qStr.Exec(w.User.PersonalNummer, w.WeekStart)
	if err != nil {
		log.Println("Error executing query!", err)
		return err
	}
	return nil
}

func (w *WorkWeek) RequiresAction() bool {
	var requiresAction bool = false
	for _, day := range w.Days {
		requiresAction = requiresAction || day.RequiresAction()
	}
	return requiresAction
}