package models

import (
	"sort"
	"time"
)

// TimelineEntry represents any item that can appear in the timeline.
type TimelineEntry struct {
	Date  time.Time
	Type  EntryType
	Event *Event
	Diary *DiaryEntry
	Photo *Photo
}

// EntryType indicates what kind of entry this is.
type EntryType string

const (
	EntryTypeEvent EntryType = "event"
	EntryTypeDiary EntryType = "diary"
	EntryTypePhoto EntryType = "photo"
)

// DayContent aggregates all content for a specific day.
type DayContent struct {
	Date   time.Time
	Events []*Event
	Diary  *DiaryEntry
	Photos []*Photo
}

// HasContent returns true if there is any content for this day.
func (d *DayContent) HasContent() bool {
	return len(d.Events) > 0 || d.Diary != nil || len(d.Photos) > 0
}

// HasEvents returns true if there are events on this day.
func (d *DayContent) HasEvents() bool {
	return len(d.Events) > 0
}

// HasDiary returns true if there is a diary entry for this day.
func (d *DayContent) HasDiary() bool {
	return d.Diary != nil
}

// HasPhotos returns true if there are photos for this day.
func (d *DayContent) HasPhotos() bool {
	return len(d.Photos) > 0
}

// ToTimelineEntries converts day content to a sorted slice of timeline entries.
func (d *DayContent) ToTimelineEntries() []TimelineEntry {
	var entries []TimelineEntry

	for _, event := range d.Events {
		entries = append(entries, TimelineEntry{
			Date:  event.Start,
			Type:  EntryTypeEvent,
			Event: event,
		})
	}

	if d.Diary != nil {
		entries = append(entries, TimelineEntry{
			Date:  d.Diary.Date,
			Type:  EntryTypeDiary,
			Diary: d.Diary,
		})
	}

	for _, photo := range d.Photos {
		entries = append(entries, TimelineEntry{
			Date:  photo.Date,
			Type:  EntryTypePhoto,
			Photo: photo,
		})
	}

	sort.Slice(entries, func(i, j int) bool {
		return entries[i].Date.Before(entries[j].Date)
	})

	return entries
}

// MonthData holds all data for a specific month.
type MonthData struct {
	Year  int
	Month time.Month
	Days  map[int]*DayContent
}

// GetDay returns the day content for a specific day number.
func (m *MonthData) GetDay(day int) *DayContent {
	if content, ok := m.Days[day]; ok {
		return content
	}
	return &DayContent{
		Date: time.Date(m.Year, m.Month, day, 0, 0, 0, 0, time.Local),
	}
}