/*
 * SPDX-FileCopyrightText: 2023 jordi fita mas <jfita@peritasoft.com>
 * SPDX-License-Identifier: AGPL-3.0-only
 */

package amenity

import (
	"context"
	"net/http"
	"strconv"

	"github.com/jackc/pgx/v4"

	"dev.tandem.ws/tandem/camper/pkg/auth"
	"dev.tandem.ws/tandem/camper/pkg/database"
	"dev.tandem.ws/tandem/camper/pkg/form"
	httplib "dev.tandem.ws/tandem/camper/pkg/http"
	"dev.tandem.ws/tandem/camper/pkg/locale"
	"dev.tandem.ws/tandem/camper/pkg/template"
)

func (h *AdminHandler) featuresHandler(user *auth.User, company *auth.Company, conn *database.Conn, label string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var head string
		head, r.URL.Path = httplib.ShiftPath(r.URL.Path)

		switch head {
		case "":
			switch r.Method {
			case http.MethodGet:
				serveFeatureIndex(w, r, user, company, conn, label)
			case http.MethodPost:
				addFeature(w, r, user, company, conn, label)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPost)
			}
		case "new":
			switch r.Method {
			case http.MethodGet:
				f := newFeatureForm(r.Context(), company, conn, label)
				f.MustRender(w, r, user, company)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet)
			}
		case "order":
			switch r.Method {
			case http.MethodPost:
				orderFeatures(w, r, user, company, conn, label)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodPost)
			}
		default:
			id, err := strconv.Atoi(head)
			if err != nil {
				http.NotFound(w, r)
				return
			}
			f := newFeatureForm(r.Context(), company, conn, label)
			if err := f.FillFromDatabase(r.Context(), conn, id); err != nil {
				if database.ErrorIsNotFound(err) {
					http.NotFound(w, r)
					return
				}
				panic(err)
			}
			h.featureHandler(user, company, conn, f).ServeHTTP(w, r)
		}
	})
}

func (h *AdminHandler) featureHandler(user *auth.User, company *auth.Company, conn *database.Conn, f *featureForm) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var head string
		head, r.URL.Path = httplib.ShiftPath(r.URL.Path)

		switch head {
		case "":
			switch r.Method {
			case http.MethodGet:
				f.MustRender(w, r, user, company)
			case http.MethodPut:
				editFeature(w, r, user, company, conn, f)
			case http.MethodDelete:
				deleteFeature(w, r, user, conn, f.Label, f.ID)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPut, http.MethodDelete)
			}
		default:
			http.NotFound(w, r)
		}
	})
}

func serveFeatureIndex(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, label string) {
	features, err := collectFeatureEntries(r.Context(), conn, company, label)
	if err != nil {
		panic(err)
	}
	page := &featureIndex{
		Label:    label,
		Features: features,
	}
	page.MustRender(w, r, user, company)
}

func collectFeatureEntries(ctx context.Context, conn *database.Conn, company *auth.Company, label string) ([]*featureEntry, error) {
	rows, err := conn.Query(ctx, `
		select amenity_feature_id
		     , '/admin/amenities/' || amenity.label || '/features/' || amenity_feature_id
		     , feature.icon_name
		     , feature.name
		from amenity_feature as feature
		    join amenity using (amenity_id)
		where amenity.label = $1
		  and amenity.company_id = $2
		order by feature.position, feature.name
	`, label, company.ID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var features []*featureEntry
	for rows.Next() {
		f := &featureEntry{}
		if err = rows.Scan(&f.ID, &f.URL, &f.Icon, &f.Name); err != nil {
			return nil, err
		}
		features = append(features, f)
	}

	return features, nil
}

type featureEntry struct {
	ID   int
	URL  string
	Icon string
	Name string
}

type featureIndex struct {
	Label    string
	Features []*featureEntry
}

func (page *featureIndex) MustRender(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company) {
	template.MustRenderAdmin(w, r, user, company, "amenity/feature/index.gohtml", page)
}

func addFeature(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, label string) {
	f := newFeatureForm(r.Context(), company, conn, label)
	processFeatureForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		var err error
		f.ID, err = tx.AddAmenityFeature(ctx, company.ID, label, f.Icon.String(), f.Name[f.DefaultLang].Val)
		if err != nil {
			return err
		}
		return translateFeatures(ctx, tx, company, f)
	})
}

func translateFeatures(ctx context.Context, tx *database.Tx, company *auth.Company, f *featureForm) error {
	for lang := range company.Locales {
		l := lang.String()
		if l == f.DefaultLang {
			continue
		}
		if err := tx.TranslateAmenityFeature(ctx, f.ID, lang, f.Name[l].Val); err != nil {
			return err
		}
	}
	return nil
}

func editFeature(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *featureForm) {
	processFeatureForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		if _, err := tx.EditAmenityFeature(ctx, f.ID, f.Icon.String(), f.Name[f.DefaultLang].Val); err != nil {
			return err
		}
		return translateFeatures(ctx, tx, company, f)
	})
}

func processFeatureForm(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *featureForm, act func(ctx context.Context, tx *database.Tx) error) {
	if ok, err := form.Handle(f, w, r, user); err != nil {
		return
	} else if !ok {
		f.MustRender(w, r, user, company)
		return
	}

	tx := conn.MustBegin(r.Context())
	defer tx.Rollback(r.Context())
	if err := act(r.Context(), tx); err == nil {
		tx.MustCommit(r.Context())
	} else {
		panic(err)
	}
	httplib.Redirect(w, r, "/admin/amenities/"+f.Label+"/features", http.StatusSeeOther)
}

func deleteFeature(w http.ResponseWriter, r *http.Request, user *auth.User, conn *database.Conn, label string, id int) {
	if err := user.VerifyCSRFToken(r); err != nil {
		http.Error(w, err.Error(), http.StatusForbidden)
		return
	}
	if err := conn.RemoveAmenityFeature(r.Context(), id); err != nil {
		panic(err)
	}
	httplib.Redirect(w, r, "/admin/amenities/"+label+"/features", http.StatusSeeOther)
}

type featureForm struct {
	DefaultLang string
	ID          int
	Label       string
	Icon        *form.Select
	Name        form.I18nInput
}

func newFeatureForm(ctx context.Context, company *auth.Company, conn *database.Conn, label string) *featureForm {
	return &featureForm{
		DefaultLang: company.DefaultLanguage.String(),
		Label:       label,
		Icon: &form.Select{
			Name:    "icon",
			Options: form.MustGetOptions(ctx, conn, "select icon_name, icon_name from icon order by 1"),
		},
		Name: form.NewI18nInput(company.Locales, "name"),
	}
}

func (f *featureForm) FillFromDatabase(ctx context.Context, conn *database.Conn, id int) error {
	f.ID = id
	var name database.RecordArray
	row := conn.QueryRow(ctx, `
		select array[icon_name]
		     , feature.name
		     , array_agg((lang_tag, i18n.name))
		from amenity_feature as feature
        left join amenity_feature_i18n as i18n using (amenity_feature_id)
		where amenity_feature_id = $1
		group by icon_name
		       , feature.name
	`, pgx.QueryResultFormats{pgx.BinaryFormatCode}, id)
	if err := row.Scan(&f.Icon.Selected, &f.Name[f.DefaultLang].Val, &name); err != nil {
		return err
	}
	if err := f.Name.FillArray(name); err != nil {
		return err
	}
	return nil
}

func (f *featureForm) Parse(r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		return err
	}
	f.Icon.FillValue(r)
	f.Name.FillValue(r)
	return nil
}

func (f *featureForm) Valid(l *locale.Locale) bool {
	v := form.NewValidator(l)
	v.CheckSelectedOptions(f.Icon, l.GettextNoop("Selected icon is not valid."))
	if v.CheckRequired(f.Name[f.DefaultLang], l.GettextNoop("Name can not be empty.")) {
		v.CheckMinLength(f.Name[f.DefaultLang], 1, l.GettextNoop("Name must have at least one letter."))
	}
	return v.AllOK
}

func (f *featureForm) MustRender(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company) {
	template.MustRenderAdmin(w, r, user, company, "amenity/feature/form.gohtml", f)
}

func orderFeatures(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, label string) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if err := user.VerifyCSRFToken(r); err != nil {
		http.Error(w, err.Error(), http.StatusForbidden)
		return
	}
	input := r.PostForm["feature_id"]
	if len(input) > 0 {
		var ids []int
		for _, s := range input {
			if id, err := strconv.Atoi(s); err == nil {
				ids = append(ids, id)
			} else {
				http.Error(w, err.Error(), http.StatusUnprocessableEntity)
				return
			}
		}
		if err := conn.OrderAmenityFeatures(r.Context(), ids); err != nil {
			panic(err)
		}
	}
	serveFeatureIndex(w, r, user, company, conn, label)
}