package api

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"strings"
	"time"

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

type plantInput struct {
	Tags            []string        `json:"tags"`
	SpeciesID       *int            `json:"species_id"`
	ClearSpeciesID  bool            `json:"clear_species_id"`
	Name            *string         `json:"name"`
	Notes           *string         `json:"notes"`
	ImageData       *string         `json:"image_data"`
	ImageID         *int            `json:"image_id"`
	AcquiredAt      *time.Time      `json:"acquired_at"`
	ClearAcquiredAt bool            `json:"clear_acquired_at"`
	Status          *string         `json:"status"`
	RemovedAt       *time.Time      `json:"removed_at"`
	Attributes      json.RawMessage `json:"attributes"`
}

func (input plantInput) apply(plant *storage.Plant) {
	if input.SpeciesID != nil {
		plant.SpeciesID = input.SpeciesID
	}
	if input.ClearSpeciesID {
		plant.SpeciesID = nil
	}
	if input.Name != nil {
		plant.Name = strings.TrimSpace(*input.Name)
	}
	if input.Notes != nil {
		plant.Notes = strings.TrimSpace(*input.Notes)
	}
	if input.ImageData != nil {
		plant.ImageData = *input.ImageData
	}
	if input.AcquiredAt != nil {
		plant.AcquiredAt = input.AcquiredAt
	}
	if input.ClearAcquiredAt {
		plant.AcquiredAt = nil
	}
	if input.Status != nil {
		plant.Status = *input.Status
	}
	if input.RemovedAt != nil {
		plant.RemovedAt = input.RemovedAt
	}
	if len(input.Attributes) != 0 {
		plant.Attributes = input.Attributes
	}
}

func (app *application) createPlantHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	var input plantInput
	if err := app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	user, _ := app.contextGetAuthenticatedUser(r)
	plant := storage.Plant{GardenID: gardenID, Status: "alive", Attributes: json.RawMessage(`{}`), CreatedBy: user.ID, UpdatedBy: user.ID, PlantedBy: user.ID}
	input.apply(&plant)
	plant.Tags = storage.NormalizeTags(input.Tags)
	if !app.validatePlantForGarden(w, r, gardenID, plant) {
		return
	}
	var err error
	plant.ImageID, err = app.resolveImage(gardenID, plant.ImageData, input.ImageID, user.ID, "plant")
	if err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	plant.ImageData = ""
	plant, err = app.models.Plants.Insert(plant)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	plant.Tags, err = app.saveTags(gardenID, storage.TagEntityPlant, plant.ID, plant.Tags)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	headers := make(http.Header)
	headers.Set("Location", fmt.Sprintf("/v1/gardens/%d/plants/%d", gardenID, plant.ID))
	if err := app.writeJSON(w, http.StatusCreated, envelope{"plant": plant}, headers); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) listPlantsHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	plants, err := app.models.Plants.GetAllForGarden(gardenID)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	user, _ := app.contextGetAuthenticatedUser(r)
	member, _ := app.contextGetGardenMember(r)
	visible := plants[:0]
	for i := range plants {
		if plants[i].CreatedBy != user.ID && !member.Can(storage.GardenPermissionPlantReadOther) {
			continue
		}
		if plants[i].CreatedBy == user.ID && !member.Can(storage.GardenPermissionPlantReadOwn) {
			continue
		}
		plants[i].Tags, err = app.loadTags(gardenID, storage.TagEntityPlant, plants[i].ID)
		if err != nil {
			app.serverErrorResponse(w, r, err)
			return
		}
		visible = append(visible, plants[i])
	}
	plants = visible
	if err := app.writeJSON(w, http.StatusOK, envelope{"plants": plants}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) showPlantHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	plant, err := app.models.Plants.Get(gardenID, id)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if !app.authorizeGardenResource(w, r, plant.CreatedBy, storage.GardenPermissionPlantReadOwn, storage.GardenPermissionPlantReadOther) {
		return
	}
	plant.Tags, err = app.loadTags(gardenID, storage.TagEntityPlant, plant.ID)
	if err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if err := app.writeJSON(w, http.StatusOK, envelope{"plant": plant}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) updatePlantHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	plant, err := app.models.Plants.Get(gardenID, id)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if !app.authorizeGardenResource(w, r, plant.CreatedBy, storage.GardenPermissionPlantUpdateOwn, storage.GardenPermissionPlantUpdateOther) {
		return
	}
	var input plantInput
	if err := app.readJSON(w, r, &input); err != nil {
		app.badRequestResponse(w, r, err)
		return
	}
	previousImageID := plant.ImageID
	previousImageData := plant.ImageData
	input.apply(&plant)
	user, _ := app.contextGetAuthenticatedUser(r)
	plant.UpdatedBy = user.ID
	if input.Tags != nil {
		plant.Tags = storage.NormalizeTags(input.Tags)
	}
	if !app.validatePlantForGarden(w, r, gardenID, plant) {
		return
	}
	if input.ImageData != nil && *input.ImageData != previousImageData {
		plant.ImageID, err = app.resolveImage(gardenID, *input.ImageData, input.ImageID, user.ID, "plant")
		if err != nil {
			app.badRequestResponse(w, r, err)
			return
		}
	}
	plant.ImageData = ""
	plant, err = app.models.Plants.Update(gardenID, plant)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if err = app.recordImageAssignment(storage.ImageAssignment{GardenID: gardenID, EntityType: "plant", EntityID: plant.ID, PreviousImageID: previousImageID, ImageID: plant.ImageID, ChangedBy: user.ID}); err != nil {
		app.serverErrorResponse(w, r, err)
		return
	}
	if input.Tags != nil {
		plant.Tags, err = app.saveTags(gardenID, storage.TagEntityPlant, plant.ID, plant.Tags)
		if err != nil {
			app.serverErrorResponse(w, r, err)
			return
		}
	}
	if err := app.writeJSON(w, http.StatusOK, envelope{"plant": plant}, nil); err != nil {
		app.serverErrorResponse(w, r, err)
	}
}

func (app *application) deletePlantHandler(w http.ResponseWriter, r *http.Request) {
	gardenID, _ := app.readGardenIDParam(r)
	id, err := app.readIDParam(r)
	if err != nil {
		app.notFoundResponse(w, r)
		return
	}
	plant, err := app.models.Plants.Get(gardenID, id)
	if err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	if !app.authorizeGardenResource(w, r, plant.CreatedBy, storage.GardenPermissionPlantDeleteOwn, storage.GardenPermissionPlantDeleteOther) {
		return
	}
	if err := app.models.Plants.Delete(gardenID, id); err != nil {
		app.respondToEntityModelError(w, r, err)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (app *application) validatePlantForGarden(w http.ResponseWriter, r *http.Request, gardenID int, plant storage.Plant) bool {
	v := validate.New()
	validateImageData(v, plant.ImageData)
	storage.ValidatePlant(v, plant)
	if plant.SpeciesID != nil && *plant.SpeciesID > 0 {
		if _, err := app.models.Species.Get(gardenID, *plant.SpeciesID); err != nil {
			if errors.Is(err, storage.ErrRecordNotFound) {
				v.AddError("species_id", "must refer to an available species")
			} else {
				app.serverErrorResponse(w, r, err)
				return false
			}
		}
	}
	if !v.Valid() {
		app.failedValidationResponse(w, r, v.Errors)
		return false
	}
	return true
}