package ticket

import (
	"encoding/json"
	"fmt"
	"time"
)

const (
	SourceTimer  = "timer"
	SourceManual = "manual"
)

// TimeEntry is a recorded block of work on a ticket.
type TimeEntry struct {
	ID        string        `json:"id"`
	TicketID  string        `json:"ticketId"`
	ProjectID string        `json:"projectId"`
	Start     time.Time     `json:"start"`
	End       time.Time     `json:"end"`
	Duration  time.Duration `json:"duration"`
	Source    string        `json:"source"`
	Note      string        `json:"note,omitempty"`
}

// MarshalJSON encodes Duration as nanoseconds for stable JSON.
func (e TimeEntry) MarshalJSON() ([]byte, error) {
	type alias struct {
		ID        string    `json:"id"`
		TicketID  string    `json:"ticketId"`
		ProjectID string    `json:"projectId"`
		Start     time.Time `json:"start"`
		End       time.Time `json:"end"`
		Duration  int64     `json:"duration"`
		Source    string    `json:"source"`
		Note      string    `json:"note,omitempty"`
	}
	return json.Marshal(alias{
		ID:        e.ID,
		TicketID:  e.TicketID,
		ProjectID: e.ProjectID,
		Start:     e.Start,
		End:       e.End,
		Duration:  int64(e.Duration),
		Source:    e.Source,
		Note:      e.Note,
	})
}

// UnmarshalJSON decodes Duration from nanoseconds.
func (e *TimeEntry) UnmarshalJSON(data []byte) error {
	type alias struct {
		ID        string    `json:"id"`
		TicketID  string    `json:"ticketId"`
		ProjectID string    `json:"projectId"`
		Start     time.Time `json:"start"`
		End       time.Time `json:"end"`
		Duration  int64     `json:"duration"`
		Source    string    `json:"source"`
		Note      string    `json:"note,omitempty"`
	}
	var a alias
	if err := json.Unmarshal(data, &a); err != nil {
		return err
	}
	e.ID = a.ID
	e.TicketID = a.TicketID
	e.ProjectID = a.ProjectID
	e.Start = a.Start
	e.End = a.End
	e.Duration = time.Duration(a.Duration)
	e.Source = a.Source
	e.Note = a.Note
	return nil
}

// ActiveTimer is a running stopwatch persisted separately until stop.
type ActiveTimer struct {
	TicketID  string    `json:"ticketId"`
	ProjectID string    `json:"projectId"`
	StartedAt time.Time `json:"startedAt"`
}

// FormatDurationHuman returns a compact duration like 2h15m or 45m.
func FormatDurationHuman(d time.Duration) string {
	if d < 0 {
		d = 0
	}
	d = d.Round(time.Second)
	h := d / time.Hour
	m := (d % time.Hour) / time.Minute
	s := (d % time.Minute) / time.Second
	switch {
	case h > 0 && m > 0:
		return fmt.Sprintf("%dh%dm", h, m)
	case h > 0:
		return fmt.Sprintf("%dh", h)
	case m > 0 && s > 0 && m < 5:
		return fmt.Sprintf("%dm%ds", m, s)
	case m > 0:
		return fmt.Sprintf("%dm", m)
	default:
		return fmt.Sprintf("%ds", s)
	}
}