package api

import (
	"bytes"
	"fmt"
	"io"
	"mime"
	"net/http"
	"path/filepath"
	"strings"
	"time"

	"gardomatic.kleiax.de/internal/platform/validate"
	"gardomatic.kleiax.de/internal/storage"
)

type journalEntryInput struct {
	Title     *string                   `json:"title"`
	Body      *string                   `json:"body"`
	CreatedAt *time.Time                `json:"created_at"`
	Tags      []string                  `json:"tags"`
	EntryType *storage.JournalEntryType `json:"entry_type"`
}

func (input journalEntryInput) apply(entry *storage.JournalEntry) {
	if input.Title != nil {
		entry.Title = strings.TrimSpace(*input.Title)
	}
	if input.Body != nil {
		entry.Body = strings.TrimSpace(*input.Body)
	}
	if input.CreatedAt != nil {
		entry.CreatedAt = input.CreatedAt.UTC()
	}
	if input.EntryType != nil {
		entry.EntryType = *input.EntryType
	}
}

func (app *application) createJournalEntryHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	user, _ := app.contextGetAuthenticatedUser(r)
	var input journalEntryInput
	if err := app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	entry := storage.JournalEntry{GardenID: gardenID, AuthorID: user.ID, AuthorName: user.Name, EntryType: storage.JournalEntryTypeJournal}
	entry.CreatedAt = time.Now().UTC()
	input.apply(&entry)
	entry.Tags = storage.NormalizeTags(input.Tags)
	if !app.validateJournalEntry(w, r, entry) {
		return
	}
	var err error
	entry, err = app.models.Journal.Insert(entry)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	entry.Tags, err = app.saveTags(gardenID, storage.TagEntityJournal, entry.ID, entry.Tags)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	headers := make(http.Header)
	headers.Set("Location", fmt.Sprintf("/v1/gardens/%d/journal/%d", gardenID, entry.ID))
	if err = app.writeJSON(w, http.StatusCreated, envelope{"journal_entry": entry}, headers); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) listJournalEntriesHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	entryType := storage.JournalEntryType(r.URL.Query().Get("type"))
	if entryType == "" {
		entryType = storage.JournalEntryTypeJournal
	}
	if entryType != storage.JournalEntryTypeJournal && entryType != storage.JournalEntryTypePinboard {
		app.badRequestResponse(w, r, fmt.Errorf("type must be journal or pinboard"))
		return
	}
	entries, err := app.models.Journal.GetAllForGarden(gardenID, entryType)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	for i := range entries {
		entries[i].Tags, err = app.loadTags(gardenID, storage.TagEntityJournal, entries[i].ID)
		if err != nil {
			app.serverErrorResponse(w, r, err)
			return
		}
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"journal_entries": entries}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) showJournalEntryHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	entry, err := app.models.Journal.Get(gardenID, id)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	entry.Tags, err = app.loadTags(gardenID, storage.TagEntityJournal, entry.ID)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"journal_entry": entry}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) updateJournalEntryHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	entry, err := app.models.Journal.Get(gardenID, id)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	var input journalEntryInput
	if err = app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	input.apply(&entry)
	if input.Tags != nil {
		entry.Tags = storage.NormalizeTags(input.Tags)
	} else {
		entry.Tags, err = app.loadTags(gardenID, storage.TagEntityJournal, id)
	}
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if !app.validateJournalEntry(w, r, entry) {
		return
	}
	entry, err = app.models.Journal.Update(gardenID, entry)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if input.Tags != nil {
		entry.Tags, err = app.saveTags(gardenID, storage.TagEntityJournal, id, entry.Tags)
	}
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if stored, getErr := app.models.Journal.Get(gardenID, id); getErr == nil {
		entry.Attachments = stored.Attachments
	}
	if err = app.writeJSON(w, http.StatusOK, envelope{"journal_entry": entry}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) deleteJournalEntryHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	if err = app.models.Journal.Delete(gardenID, id); err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) createJournalAttachmentHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	entryID, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	r.Body = http.MaxBytesReader(w, r.Body, storage.MaxJournalAttachmentSize+(1<<20))
	file, header, err := r.FormFile("file")
	if err != nil {
		app.badRequestResponse(w, r, fmt.Errorf("file must be provided"))
		return
	}
	defer file.Close()
	data, err := io.ReadAll(io.LimitReader(file, storage.MaxJournalAttachmentSize+1))
	if err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	if len(data) > storage.MaxJournalAttachmentSize {
		app.badRequestResponse(w, r, fmt.Errorf("file must not be larger than 25 MB"))
		return
	}
	mediaType := strings.ToLower(strings.TrimSpace(strings.Split(header.Header.Get("Content-Type"), ";")[0]))
	detected := http.DetectContentType(data)
	if mediaType == "" || mediaType == "application/octet-stream" {
		mediaType = detected
	}
	if !allowedJournalMediaType(mediaType) {
		app.badRequestResponse(w, r, fmt.Errorf("only photos, videos and audio files are supported"))
		return
	}
	name := filepath.Base(strings.ReplaceAll(header.Filename, "\\", "/"))
	if name == "." || name == "" {
		name = "attachment"
	}
	if len(name) > 255 {
		name = name[:255]
	}
	attachment, err := app.models.Journal.InsertAttachment(gardenID, entryID, storage.JournalAttachment{FileName: name, MediaType: mediaType, Data: data})
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusCreated, envelope{"attachment": attachment}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) createJournalLibraryAttachmentHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	entryID, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	var input struct {
		ImageID int `json:"image_id"`
	}
	if err = app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	if input.ImageID < 1 {
		app.badRequestResponse(w, r, fmt.Errorf("image_id must be provided"))
		return
	}
	image, err := app.models.Images.Get(gardenID, input.ImageID)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	name := image.FileName
	if name == "" {
		name = "Bild"
	}
	attachment, err := app.models.Journal.InsertAttachment(gardenID, entryID, storage.JournalAttachment{FileName: name, MediaType: image.MediaType, Size: image.Size, ImageID: &image.ID})
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if err = app.writeJSON(w, http.StatusCreated, envelope{"attachment": attachment}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func allowedJournalMediaType(value string) bool {
	switch value {
	case "image/jpeg", "image/png", "image/webp", "image/gif", "video/mp4", "video/webm", "video/quicktime", "audio/mpeg", "audio/mp4", "audio/ogg", "audio/webm", "audio/wav", "audio/x-wav":
		return true
	default:
		return false
	}
}

func (app *application) showJournalAttachmentHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	entryID, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	attachmentID, err := app.readNamedIDParam(r, "attachmentID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	a, err := app.models.Journal.GetAttachment(gardenID, entryID, attachmentID)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	w.Header().Set("Content-Type", a.MediaType)
	w.Header().Set("Content-Disposition", mime.FormatMediaType("inline", map[string]string{"filename": a.FileName}))
	w.Header().Set("Cache-Control", "private, max-age=3600")
	http.ServeContent(w, r, a.FileName, a.CreatedAt, bytes.NewReader(a.Data))
}

func (app *application) deleteJournalAttachmentHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	entryID, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	attachmentID, err := app.readNamedIDParam(r, "attachmentID")
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	if err = app.models.Journal.DeleteAttachment(gardenID, entryID, attachmentID); err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) validateJournalEntry(w http.ResponseWriter, r *http.Request, entry storage.JournalEntry) bool {
	v := validate.New()
	storage.ValidateJournalEntry(v, entry)
	storage.ValidateTags(v, entry.Tags)
	if !v.Valid() {
		app.failedValidationResponse(w, r, v.Errors)
		return false
	}
	return true
}