package gotime

import (
	"errors"
	"strings"
	"time"
)

type Timer struct {
	Id         int
	Beg        time.Time
	End        time.Time
	Tags       []string
	timeFormat string
}

// CreateTimerFromString takes a string in the format of the lines from the data file
// and builds a timer from it.
func CreateTimerFromString(st string) (*Timer, error) {
	var err error
	t := new(Timer)
	t.timeFormat = "20060102T150405Z"
	flds := strings.Fields(st)
	if len(flds) > 1 && flds[0] == "inc" {
		// Start Time
		if len(flds) >= 2 {
			if t.Beg, err = time.Parse(t.timeFormat, flds[1]); err != nil {
				return t, err
			}
		}
		// End Time
		if len(flds) >= 4 && flds[2] == "-" {
			if t.End, err = time.Parse(t.timeFormat, flds[3]); err != nil {
				return t, err
			}
		}
		var inTags bool
		for i := range flds {
			if flds[i] == "#" {
				inTags = true
				continue
			}
			if inTags {
				tg := strings.Trim(flds[i], "\"")
				t.AddTag(tg)
			}
		}
	}
	return t, err
}

func (t *Timer) Start() {
	if t.Beg.IsZero() {
		t.Beg = time.Now()
	}
}

func (t *Timer) Stop() {
	if t.End.IsZero() {
		t.End = time.Now()
	}
}

func (t *Timer) SetId(i int) {
	t.Id = i
}

func (t *Timer) SetStart(tm time.Time) error {
	if !t.End.IsZero() && !tm.Before(t.End) {
		return errors.New("Beginning time must be before End")
	}
	t.Beg = tm
	return nil
}

func (t *Timer) SetEnd(tm time.Time) error {
	if !tm.After(t.Beg) {
		return errors.New("End time must be after Beginning")
	}
	t.End = tm
	return nil
}

func (t *Timer) IsRunning() bool {
	return !t.Beg.IsZero() && t.End.IsZero()
}

// AddTag adds the tag tg to this timer
func (t *Timer) AddTag(tg string) {
	if !t.HasTag(tg) {
		t.Tags = append(t.Tags, tg)
	}
}

// RemoveTag removes the tag tg from this timer
func (t *Timer) RemoveTag(tg string) {
	for i := 0; i < len(t.Tags); i++ {
		if t.Tags[i] == tg {
			t.Tags = append(t.Tags[:i], t.Tags[i+1:]...)
		}
	}
}

// HasTag returns if this timer has the tag
func (t *Timer) HasTag(tg string) bool {
	for i := range t.Tags {
		if t.Tags[i] == tg {
			return true
		}
	}
	return false
}

func (t *Timer) ToString() string {
	if t.Beg.IsZero() {
		return ""
	}
	timeFormat := "20060102T150405Z"

	ret := "inc " + t.Beg.Format(timeFormat)
	if !t.End.IsZero() {
		ret += " - " + t.End.Format(timeFormat)
	}
	if len(t.Tags) > 0 {
		ret += " # "
		for i := range t.Tags {
			if TagIsMultiword(t.Tags[i]) {
				ret += "\""
			}
			ret += t.Tags[i]
			if TagIsMultiword(t.Tags[i]) {
				ret += "\""
			}
			ret += " "
		}
		ret = ret[:len(ret)-1]
	}
	return ret
}

func (t *Timer) ToJsonString() string {
	if t.Beg.IsZero() {
		return ""
	}
	timeFormat := "20060102T150405Z"

	ret := "{\"start\":\"" + t.Beg.Format(timeFormat) + "\","
	if !t.End.IsZero() {
		ret += "\"end\":\"" + t.End.Format(timeFormat) + "\","
	}
	if len(t.Tags) > 0 {
		ret += "\"tags\":["
		for i := range t.Tags {
			ret += "\"" + t.Tags[i] + "\","
		}
		// Move trailing ',' to end
		ret = ret[:len(ret)-1] + "],"

	}
	// Trim trailing ,
	ret = ret[:len(ret)-1] + "}"
	return ret
}