package api

import "git.golem15.com/jakub/sm-bm-plugin/models"

// idOf is the value of an optional id, 0 when it is nil. The API serves only
// sessions and readings that have a course, so their course_id is set.
func idOf(id *uint) uint {
	if id == nil {
		return 0
	}
	return *id
}

// courseRef is the short form of a course embedded in other records.
type courseRef struct {
	ID       uint    `json:"id"`
	Code     *string `json:"code"`
	Name     string  `json:"name"`
	Form     string  `json:"form"`
	Semester int     `json:"semester"`
}

func newCourseRef(c *models.Course) *courseRef {
	if c == nil {
		return nil
	}
	return &courseRef{ID: c.ID, Code: c.Code, Name: c.Name, Form: c.Form, Semester: c.Semester}
}

// courseJSON is a course's own fields.
type courseJSON struct {
	ID            uint     `json:"id"`
	Code          *string  `json:"code"`
	Name          string   `json:"name"`
	Form          string   `json:"form"`
	Lecturer      *string  `json:"lecturer"`
	Semester      int      `json:"semester"`
	ECTS          *float64 `json:"ects"`
	Assessment    *string  `json:"assessment"`
	ElectiveGroup *string  `json:"elective_group"`
	Description   *string  `json:"description"`
	SyllabusURL   *string  `json:"syllabus_url"`
	SortOrder     int      `json:"sort_order"`
}

func newCourseJSON(c models.Course) courseJSON {
	return courseJSON{
		ID:            c.ID,
		Code:          c.Code,
		Name:          c.Name,
		Form:          c.Form,
		Lecturer:      c.Lecturer,
		Semester:      c.Semester,
		ECTS:          c.ECTS,
		Assessment:    c.Assessment,
		ElectiveGroup: c.ElectiveGroup,
		Description:   c.Description,
		SyllabusURL:   c.SyllabusURL,
		SortOrder:     c.SortOrder,
	}
}

// courseCounts are the per-course counters of /courses and /courses/{id}.
type courseCounts struct {
	Sessions     int64 `json:"sessions"`
	Readings     int64 `json:"readings"`
	ReadingsRead int64 `json:"readings_read"`
	Materials    int64 `json:"materials"`
}

type courseListJSON struct {
	courseJSON
	Counts courseCounts `json:"counts"`
}

type courseDetailJSON struct {
	courseJSON
	Counts    courseCounts       `json:"counts"`
	Sessions  []sessionJSON      `json:"sessions"`
	Readings  []readingJSON      `json:"readings"`
	Materials []materialListJSON `json:"materials"`
}

// meetingJSON is one zjazd.
type meetingJSON struct {
	ID            uint    `json:"id"`
	Number        int     `json:"number"`
	StartsOn      string  `json:"starts_on"`
	EndsOn        string  `json:"ends_on"`
	Notes         *string `json:"notes"`
	SessionsCount int64   `json:"sessions_count"`
}

func newMeetingJSON(m models.Meeting, sessions int64) meetingJSON {
	return meetingJSON{ID: m.ID, Number: m.Number, StartsOn: m.StartsOn.String(), EndsOn: m.EndsOn.String(), Notes: m.Notes, SessionsCount: sessions}
}

// sessionJSON is one class session with its course.
type sessionJSON struct {
	ID            uint       `json:"id"`
	CourseID      uint       `json:"course_id"`
	MeetingID     *uint      `json:"meeting_id"`
	MeetingNumber *int       `json:"meeting_number"`
	StartsAt      string     `json:"starts_at"`
	EndsAt        string     `json:"ends_at"`
	Room          *string    `json:"room"`
	Kind          *string    `json:"kind"`
	Notes         *string    `json:"notes"`
	IsOnline      bool       `json:"is_online"`
	Course        *courseRef `json:"course"`
}

func newSessionJSON(s models.ClassSession) sessionJSON {
	out := sessionJSON{
		ID:        s.ID,
		CourseID:  idOf(s.CourseID),
		MeetingID: s.MeetingID,
		StartsAt:  models.FormatDateTime(s.StartsAt),
		EndsAt:    models.FormatDateTime(s.EndsAt),
		Room:      s.Room,
		Kind:      s.Kind,
		Notes:     s.Notes,
		IsOnline:  s.IsOnline,
		Course:    newCourseRef(s.Course),
	}
	if s.Meeting != nil {
		n := s.Meeting.Number
		out.MeetingNumber = &n
	}
	return out
}

func newSessionsJSON(rows []models.ClassSession) []sessionJSON {
	out := make([]sessionJSON, 0, len(rows))
	for _, s := range rows {
		out = append(out, newSessionJSON(s))
	}
	return out
}

// deadlineJSON is one terminarz entry.
type deadlineJSON struct {
	ID          uint       `json:"id"`
	Title       string     `json:"title"`
	DueAt       string     `json:"due_at"`
	Kind        string     `json:"kind"`
	Description *string    `json:"description"`
	CourseID    *uint      `json:"course_id"`
	Course      *courseRef `json:"course"`
}

func newDeadlinesJSON(rows []models.Deadline) []deadlineJSON {
	out := make([]deadlineJSON, 0, len(rows))
	for _, d := range rows {
		out = append(out, deadlineJSON{
			ID:          d.ID,
			Title:       d.Title,
			DueAt:       models.FormatDateTime(d.DueAt),
			Kind:        d.Kind,
			Description: d.Description,
			CourseID:    d.CourseID,
			Course:      newCourseRef(d.Course),
		})
	}
	return out
}

// readingJSON is one reading with the caller's read state.
type readingJSON struct {
	ID         uint       `json:"id"`
	CourseID   uint       `json:"course_id"`
	Course     *courseRef `json:"course"`
	Title      string     `json:"title"`
	Author     *string    `json:"author"`
	Source     *string    `json:"source"`
	URL        *string    `json:"url"`
	IsRequired bool       `json:"is_required"`
	SortOrder  int        `json:"sort_order"`
	ReadAt     *string    `json:"read_at"`
}

// tagJSON is one material tag.
type tagJSON struct {
	ID   uint   `json:"id"`
	Name string `json:"name"`
	Slug string `json:"slug"`
}

func newTagsJSON(tags []models.Tag) []tagJSON {
	out := make([]tagJSON, 0, len(tags))
	for _, t := range tags {
		out = append(out, tagJSON{ID: t.ID, Name: t.Name, Slug: t.Slug})
	}
	return out
}

// materialListJSON is a published material in a list.
type materialListJSON struct {
	ID          uint       `json:"id"`
	CourseID    *uint      `json:"course_id"`
	Course      *courseRef `json:"course"`
	Title       string     `json:"title"`
	Type        string     `json:"type"`
	Source      *string    `json:"source"`
	URL         *string    `json:"url"`
	PublishedAt string     `json:"published_at"`
	Tags        []tagJSON  `json:"tags"`
	FilesCount  int64      `json:"files_count"`
}

func newMaterialListJSON(m models.Material, files int64) materialListJSON {
	out := materialListJSON{
		ID:         m.ID,
		CourseID:   m.CourseID,
		Course:     newCourseRef(m.Course),
		Title:      m.Title,
		Type:       m.Type,
		Source:     m.Source,
		URL:        m.URL,
		Tags:       newTagsJSON(m.Tags),
		FilesCount: files,
	}
	if m.PublishedAt != nil {
		out.PublishedAt = models.FormatDateTime(*m.PublishedAt)
	}
	return out
}

// materialDetailJSON is a published material with its body and files.
type materialDetailJSON struct {
	materialListJSON
	Body  *string    `json:"body"`
	Files []fileJSON `json:"files"`
}

// fileJSON is one attached file.
type fileJSON struct {
	ID   uint   `json:"id"`
	URL  string `json:"url"`
	Name string `json:"name"`
	Size int64  `json:"size"`
	Mime string `json:"mime"`
}

// readingsSummary is the reading progress block of /dashboard.
type readingsSummary struct {
	Total         int64 `json:"total"`
	Read          int64 `json:"read"`
	RequiredTotal int64 `json:"required_total"`
	RequiredRead  int64 `json:"required_read"`
}