package web

import (
	"errors"
	"net/http"
	"strconv"
	"strings"
	"time"

	"gardomatic.kleiax.de/lib/client"
)

type plantForm struct {
	CSRFToken               string                `form:"csrf_token"`
	Name                    string                `form:"name"`
	SpeciesID               int                   `form:"species_id"`
	LocationIDs             []int                 `form:"location_id"`
	Quantities              []int                 `form:"quantity"`
	AssignmentIDs           []int                 `form:"assignment_id"`
	Assignments             []plantAssignmentForm `form:"-"`
	TaskIDs                 []int                 `form:"plant_task_id"`
	TaskRowKeys             []string              `form:"plant_task_row_key"`
	TaskTitles              []string              `form:"plant_task_title"`
	TaskDescriptions        []string              `form:"plant_task_description"`
	TaskDueAtStarts         []string              `form:"plant_task_due_at_start"`
	TaskDueAtEnds           []string              `form:"plant_task_due_at_end"`
	TaskPriorities          []int                 `form:"plant_task_priority"`
	TaskPlantIDs            []int                 `form:"plant_task_plant_id"`
	TaskLocationIDs         []int                 `form:"plant_task_location_id"`
	TaskRecurrences         []string              `form:"plant_task_recurrence"`
	TaskRecurrenceIntervals []int                 `form:"plant_task_recurrence_interval"`
	TaskKeywords            []string              `form:"plant_task_keywords"`
	TaskStatuses            []string              `form:"plant_task_status_on_completion"`
	TaskActives             []bool                `form:"plant_task_active"`
	TaskDeletes             []bool                `form:"plant_task_delete"`
	Tasks                   []plantTaskForm       `form:"-"`
	Notes                   string                `form:"notes"`
	ImageData               string                `form:"image_data"`
	ImageID                 int                   `form:"image_id"`
	AcquiredAt              string                `form:"acquired_at"`
	Status                  string                `form:"status"`
	Keywords                string                `form:"keywords"`
	Errors                  map[string]string
}

type plantTaskForm struct {
	ID, Priority, PlantID, LocationID, RecurrenceInterval             int
	RowKey                                                            string
	Title, Description, Recurrence, Keywords, PlantStatusOnCompletion string
	PendingPlantName                                                  string
	DueAtStart, DueAtEnd                                              string
	Active, Delete                                                    bool
	Errors                                                            map[string]string
}

type plantAssignmentForm struct {
	AssignmentID int
	LocationID   int
	Quantity     int
}

func (form *plantForm) buildAssignments() {
	form.Assignments = make([]plantAssignmentForm, len(form.LocationIDs))
	for i, locationID := range form.LocationIDs {
		form.Assignments[i].LocationID = locationID
		if i < len(form.Quantities) {
			form.Assignments[i].Quantity = form.Quantities[i]
		}
		if i < len(form.AssignmentIDs) {
			form.Assignments[i].AssignmentID = form.AssignmentIDs[i]
		}
	}
}

func (form *plantForm) buildTasks() {
	form.Tasks = make([]plantTaskForm, len(form.TaskTitles))
	for i := range form.TaskTitles {
		form.Tasks[i].Title = strings.TrimSpace(form.TaskTitles[i])
		if i < len(form.TaskIDs) {
			form.Tasks[i].ID = form.TaskIDs[i]
		}
		if i < len(form.TaskRowKeys) {
			form.Tasks[i].RowKey = form.TaskRowKeys[i]
		}
		if i < len(form.TaskDescriptions) {
			form.Tasks[i].Description = strings.TrimSpace(form.TaskDescriptions[i])
		}
		if i < len(form.TaskDueAtStarts) {
			form.Tasks[i].DueAtStart = form.TaskDueAtStarts[i]
		}
		if i < len(form.TaskDueAtEnds) {
			form.Tasks[i].DueAtEnd = form.TaskDueAtEnds[i]
		}
		if i < len(form.TaskPriorities) {
			form.Tasks[i].Priority = form.TaskPriorities[i]
		}
		if i < len(form.TaskPlantIDs) {
			form.Tasks[i].PlantID = form.TaskPlantIDs[i]
		}
		if i < len(form.TaskLocationIDs) {
			form.Tasks[i].LocationID = form.TaskLocationIDs[i]
		}
		if i < len(form.TaskRecurrences) {
			form.Tasks[i].Recurrence = form.TaskRecurrences[i]
		}
		if i < len(form.TaskRecurrenceIntervals) {
			form.Tasks[i].RecurrenceInterval = form.TaskRecurrenceIntervals[i]
		}
		if i < len(form.TaskKeywords) {
			form.Tasks[i].Keywords = form.TaskKeywords[i]
		}
		if i < len(form.TaskStatuses) {
			form.Tasks[i].PlantStatusOnCompletion = form.TaskStatuses[i]
		}
		if i < len(form.TaskActives) {
			form.Tasks[i].Active = form.TaskActives[i]
		}
		if i < len(form.TaskDeletes) {
			form.Tasks[i].Delete = form.TaskDeletes[i]
		}
		if form.Tasks[i].RowKey == "" {
			form.Tasks[i].RowKey = "task-" + strconv.Itoa(form.Tasks[i].ID) + "-" + strconv.Itoa(i)
		}
	}
}

func (app *application) plants(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	apiClient := client.FromContext(r.Context())
	garden, _, err := apiClient.Garden(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	plants, _, err := apiClient.Plants(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	species, _, err := apiClient.SpeciesForGarden(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data := app.newTemplateData(r)
	data.Garden = &garden
	data.Plants = plants
	data.Species = species
	locations, _, err := apiClient.Locations(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data.Locations = locations
	data.LocationNames = make(map[int]string, len(locations))
	for _, location := range locations {
		data.LocationNames[location.ID] = location.Name
	}
	data.PlantLocations = make(map[int][]client.PlantLocation, len(plants))
	for _, plant := range plants {
		assignments, _, assignmentErr := apiClient.PlantLocations(r.Context(), gardenID, plant.ID)
		if assignmentErr != nil {
			app.handleAPIError(w, r, assignmentErr)
			return
		}
		data.PlantLocations[plant.ID] = assignments
	}
	data.Filters = collectionFilters(r, "q", "status", "species", "location", "sort")
	data.Plants = filterAndSortPlants(plants, data.PlantLocations, data.Filters)
	data.Plants, data.Pagination = paginateCollection(r, data.Plants)
	app.render(w, http.StatusOK, "plant.tmpl", data)
}

func (app *application) plantCreate(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	locationID, _ := strconv.Atoi(r.URL.Query().Get("location_id"))
	app.renderPlantForm(w, r, gardenID, plantForm{Status: "alive", Assignments: []plantAssignmentForm{{LocationID: locationID, Quantity: 1}}, Errors: make(map[string]string)}, http.StatusOK)
}

func (app *application) plantCreatePost(w http.ResponseWriter, r *http.Request) {
	app.plantSave(w, r)
}

func (app *application) plantEdit(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	plantID, err := app.readPathID(r, "plantID")
	if err != nil {
		app.notFound(w)
		return
	}
	apiClient := client.FromContext(r.Context())
	plant, _, err := apiClient.Plant(r.Context(), gardenID, plantID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	form := plantForm{Name: plant.Name, Notes: plant.Notes, ImageData: plant.ImageData, Status: plant.Status, Keywords: strings.Join(plant.Tags, ", "), Errors: map[string]string{}}
	if plant.ImageID != nil {
		form.ImageID = *plant.ImageID
	}
	if plant.SpeciesID != nil {
		form.SpeciesID = *plant.SpeciesID
	}
	if plant.AcquiredAt != nil {
		form.AcquiredAt = plant.AcquiredAt.Format("2006-01-02")
	}
	assignments, _, err := apiClient.PlantLocations(r.Context(), gardenID, plantID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	for _, assignment := range assignments {
		form.Assignments = append(form.Assignments, plantAssignmentForm{AssignmentID: assignment.ID, LocationID: assignment.LocationID, Quantity: assignment.Quantity})
	}
	if len(form.Assignments) == 0 {
		form.Assignments = []plantAssignmentForm{{Quantity: 1}}
	}
	app.renderPlantForm(w, r, gardenID, form, http.StatusOK, plantID)
}

func (app *application) plantEditPost(w http.ResponseWriter, r *http.Request) { app.plantSave(w, r) }

func (app *application) plantSave(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	plantID := 0
	if id, readErr := app.readPathID(r, "plantID"); readErr == nil {
		plantID = id
	}
	var form plantForm
	if err := app.decodePostForm(r, &form); err != nil {
		app.clientError(w, http.StatusBadRequest)
		return
	}
	form.buildAssignments()
	form.buildTasks()
	form.Name = strings.TrimSpace(form.Name)
	form.Notes = strings.TrimSpace(form.Notes)
	form.Errors = make(map[string]string)
	if form.Name == "" {
		form.Errors["name"] = "Ein Name ist erforderlich."
	}
	if form.Status == "" {
		form.Status = "alive"
	}
	for i, assignment := range form.Assignments {
		if assignment.LocationID > 0 && assignment.Quantity < 1 {
			form.Errors["quantity_"+strconv.Itoa(i)] = "Die Anzahl muss mindestens 1 sein."
		}
	}
	for i, task := range form.Tasks {
		if task.Delete {
			continue
		}
		if task.Title == "" {
			form.Errors["plant_task_title_"+strconv.Itoa(i)] = "Ein Titel ist erforderlich."
		}
		start, _ := parseTaskTime(task.DueAtStart, "plant_task_due_at_start_"+strconv.Itoa(i), form.Errors)
		end, _ := parseTaskTime(task.DueAtEnd, "plant_task_due_at_end_"+strconv.Itoa(i), form.Errors)
		if start != nil && end != nil && start.After(*end) {
			form.Errors["plant_task_due_at_end_"+strconv.Itoa(i)] = "Das Ende darf nicht vor dem Beginn liegen."
		}
	}
	var acquiredAt *time.Time
	if form.AcquiredAt != "" {
		parsed, parseErr := time.Parse("2006-01-02", form.AcquiredAt)
		if parseErr != nil {
			form.Errors["acquired_at"] = "Das Datum ist ungültig."
		} else {
			acquiredAt = &parsed
		}
	}
	if len(form.Errors) == 0 {
		name, notes, status := form.Name, form.Notes, form.Status
		imageData := form.ImageData
		input := client.PlantInput{Name: &name, Notes: &notes, ImageData: &imageData, Status: &status, AcquiredAt: acquiredAt, ClearAcquiredAt: acquiredAt == nil, Tags: parseKeywords(form.Keywords)}
		if form.ImageID > 0 {
			imageID := form.ImageID
			input.ImageID = &imageID
		}
		if form.SpeciesID > 0 {
			speciesID := form.SpeciesID
			input.SpeciesID = &speciesID
		} else {
			input.ClearSpeciesID = true
		}
		apiClient := client.FromContext(r.Context())
		var plant client.Plant
		if plantID > 0 {
			plant, _, err = apiClient.UpdatePlant(r.Context(), gardenID, plantID, input)
		} else {
			plant, _, err = apiClient.CreatePlant(r.Context(), gardenID, input)
		}
		if err == nil {
			for _, assignment := range form.Assignments {
				if assignment.LocationID == 0 {
					if assignment.AssignmentID > 0 {
						_, err = apiClient.DeletePlantLocation(r.Context(), gardenID, plant.ID, assignment.AssignmentID)
					}
				} else {
					locationID, quantity := assignment.LocationID, assignment.Quantity
					assignmentInput := client.PlantLocationInput{LocationID: &locationID, Quantity: &quantity, PlantedAt: acquiredAt, ClearPlantedAt: acquiredAt == nil}
					if assignment.AssignmentID > 0 {
						_, _, err = apiClient.UpdatePlantLocation(r.Context(), gardenID, plant.ID, assignment.AssignmentID, assignmentInput)
					} else {
						_, _, err = apiClient.CreatePlantLocation(r.Context(), gardenID, plant.ID, assignmentInput)
					}
				}
				if err != nil {
					break
				}
			}
			if err == nil {
				err = app.savePlantTasks(r, gardenID, plant.ID, form.Tasks)
			}
			if err == nil && form.SpeciesID > 0 {
				err = app.savePlantTemplateStates(r, gardenID, plant.ID, form.SpeciesID)
			}
			if err != nil && plantID == 0 {
				_, _ = apiClient.DeletePlant(r.Context(), gardenID, plant.ID)
			}
		}
		if err == nil {
			http.Redirect(w, r, webPath("plants", gardenID), http.StatusSeeOther)
			return
		}
		var apiError *client.APIError
		if errors.As(err, &apiError) && apiError.StatusCode == http.StatusUnprocessableEntity {
			form.Errors = apiError.Validation
		} else {
			app.handleAPIError(w, r, err)
			return
		}
	}
	app.renderPlantForm(w, r, gardenID, form, http.StatusUnprocessableEntity, plantID)
}

func (app *application) plantStatusPost(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	plantID, err := app.readPathID(r, "plantID")
	if err != nil {
		app.notFound(w)
		return
	}
	if err = r.ParseForm(); err != nil {
		app.clientError(w, http.StatusBadRequest)
		return
	}
	status := r.PostForm.Get("status")
	if status != "alive" && status != "dead" && status != "removed" && status != "infested" && status != "harvested" && status != "dormant" {
		app.clientError(w, http.StatusUnprocessableEntity)
		return
	}
	if _, _, err = client.FromContext(r.Context()).UpdatePlant(r.Context(), gardenID, plantID, client.PlantInput{Status: &status}); err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	http.Redirect(w, r, webPath("plants", gardenID), http.StatusSeeOther)
}

func (app *application) plantDelete(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	plantID, err := app.readPathID(r, "plantID")
	if err != nil {
		app.notFound(w)
		return
	}
	if _, err := client.FromContext(r.Context()).DeletePlant(r.Context(), gardenID, plantID); err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	http.Redirect(w, r, webPath("plants", gardenID), http.StatusSeeOther)
}

func (app *application) plantTemplateOptOutPost(w http.ResponseWriter, r *http.Request) {
	gardenID, err := app.readPathID(r, "gardenID")
	if err != nil {
		app.notFound(w)
		return
	}
	plantID, err := app.readPathID(r, "plantID")
	if err != nil {
		app.notFound(w)
		return
	}
	templateID, err := app.readPathID(r, "templateID")
	if err != nil {
		app.notFound(w)
		return
	}
	if err = r.ParseForm(); err != nil {
		app.clientError(w, http.StatusBadRequest)
		return
	}
	optedOut := r.PostForm.Get("opted_out") != "false"
	if _, err = client.FromContext(r.Context()).SetTaskTemplateOptOut(r.Context(), gardenID, plantID, templateID, optedOut); err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	http.Redirect(w, r, webPath("plant.edit", gardenID, plantID), http.StatusSeeOther)
}

func (app *application) renderPlantForm(w http.ResponseWriter, r *http.Request, gardenID int, form plantForm, status int, plantIDs ...int) {
	apiClient := client.FromContext(r.Context())
	garden, _, err := apiClient.Garden(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	species, _, err := apiClient.SpeciesForGarden(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data := app.newTemplateData(r)
	data.Garden = &garden
	data.Species = species
	priorities, _, err := apiClient.TaskPriorities(r.Context())
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data.TaskPriorities = priorities
	locations, _, err := apiClient.Locations(r.Context(), gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data.Locations = locations
	images, err := app.loadImageLibrary(r, gardenID)
	if err != nil {
		app.handleAPIError(w, r, err)
		return
	}
	data.Images = images
	data.Form = form
	data.SpeciesID = form.SpeciesID
	data.TaskTemplates = map[int][]client.SpeciesTaskTemplate{}
	data.TemplateOptOuts = map[int]bool{}
	if len(plantIDs) > 0 {
		data.PlantID = plantIDs[0]
		plant, _, plantErr := apiClient.Plant(r.Context(), gardenID, data.PlantID)
		if plantErr != nil {
			app.handleAPIError(w, r, plantErr)
			return
		}
		data.PlantCreatedBy = plant.CreatedBy
		if form.Tasks == nil {
			tasks, _, taskErr := apiClient.Tasks(r.Context(), gardenID)
			var apiError *client.APIError
			if taskErr != nil && !(errors.As(taskErr, &apiError) && apiError.StatusCode == http.StatusNotFound) {
				app.handleAPIError(w, r, taskErr)
				return
			}
			for _, task := range tasks {
				if task.PlantID == nil || *task.PlantID != data.PlantID || task.TemplateID != nil {
					continue
				}
				active := task.Active == nil || *task.Active
				item := plantTaskForm{ID: task.ID, PlantID: data.PlantID, RowKey: "task-" + strconv.Itoa(task.ID), Title: task.Title, Description: task.Description, Priority: task.Priority, Active: active, Recurrence: task.Recurrence, RecurrenceInterval: task.RecurrenceInterval, Keywords: strings.Join(task.Tags, ", ")}
				if task.LocationID != nil {
					item.LocationID = *task.LocationID
				}
				if task.PlantStatusOnCompletion != nil {
					item.PlantStatusOnCompletion = *task.PlantStatusOnCompletion
				}
				if task.DueAtStart != nil {
					item.DueAtStart = task.DueAtStart.Local().Format("2006-01-02")
				}
				if task.DueAtEnd != nil {
					item.DueAtEnd = task.DueAtEnd.Local().Format("2006-01-02")
				}
				form.Tasks = append(form.Tasks, item)
			}
			data.Form = form
		}
		if form.SpeciesID > 0 {
			ids, _, optErr := apiClient.TaskTemplateOptOuts(r.Context(), gardenID, data.PlantID)
			if optErr != nil {
				app.handleAPIError(w, r, optErr)
				return
			}
			for _, id := range ids {
				data.TemplateOptOuts[id] = true
			}
		}
	}
	if form.SpeciesID > 0 {
		templates, _, templateErr := apiClient.SpeciesTaskTemplates(r.Context(), gardenID, form.SpeciesID)
		if templateErr != nil {
			app.handleAPIError(w, r, templateErr)
			return
		}
		data.TaskTemplates[form.SpeciesID] = templates
		for _, item := range templates {
			if values, present := r.PostForm["plant_template_active_"+strconv.Itoa(item.ID)]; present {
				data.TemplateOptOuts[item.ID] = len(values) == 0 || values[len(values)-1] != "true"
			}
		}
	}
	app.render(w, status, "plant_form.tmpl", data)
}