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

package services

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

	"github.com/jackc/pgx/v4"

	"dev.tandem.ws/tandem/camper/pkg/auth"
	"dev.tandem.ws/tandem/camper/pkg/carousel"
	"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"
)

const carouselName = "services"

type AdminHandler struct {
	locales  locale.Locales
	carousel *carousel.AdminHandler
}

func NewAdminHandler(locales locale.Locales) *AdminHandler {
	return &AdminHandler{
		locales:  locales,
		carousel: carousel.NewAdminHandler(carouselName, locales),
	}
}

func (h *AdminHandler) Handler(user *auth.User, company *auth.Company, conn *database.Conn) 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:
				serveHomeIndex(w, r, user, company, conn)
			case http.MethodPost:
				addService(w, r, user, company, conn)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPost)
			}
		case "new":
			switch r.Method {
			case http.MethodGet:
				f := newServiceForm(r.Context(), conn)
				f.MustRender(w, r, user, company)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet)
			}
		case "slides":
			h.carousel.Handler(user, company, conn).ServeHTTP(w, r)
		default:
			id, err := strconv.Atoi(head)
			if err != nil {
				http.NotFound(w, r)
				return
			}
			f := newServiceForm(r.Context(), conn)
			if err := f.FillFromDatabase(r.Context(), conn, id); err != nil {
				if database.ErrorIsNotFound(err) {
					http.NotFound(w, r)
					return
				}
				panic(err)
			}

			var langTag string
			langTag, r.URL.Path = httplib.ShiftPath(r.URL.Path)

			switch langTag {
			case "":
				switch r.Method {
				case http.MethodGet:
					f.MustRender(w, r, user, company)
				case http.MethodPut:
					editService(w, r, user, company, conn, f)
				case http.MethodDelete:
					deleteService(w, r, user, conn, id)
				default:
					httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPut, http.MethodDelete)
				}
			default:
				loc, ok := h.locales.Get(langTag)
				if !ok {
					http.NotFound(w, r)
					return
				}
				l10n := newServiceL10nForm(f, loc)
				if err := l10n.FillFromDatabase(r.Context(), conn); err != nil {
					panic(err)
				}
				switch r.Method {
				case http.MethodGet:
					l10n.MustRender(w, r, user, company)
				case http.MethodPut:
					editServiceL10n(w, r, user, company, conn, l10n)
				default:
					httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPut)
				}
			}
		}
	})
}

func serveHomeIndex(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn) {
	slides, err := carousel.CollectSlideEntries(r.Context(), company, conn, carouselName)
	if err != nil {
		panic(err)
	}
	services, err := collectServiceEntries(r.Context(), company, conn)
	page := &servicesIndex{
		Services: services,
		Slides:   slides,
	}
	page.MustRender(w, r, user, company)
}

type servicesIndex struct {
	Services []*serviceEntry
	Slides   []*carousel.SlideEntry
}

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

type serviceEntry struct {
	URL          string
	Icon         string
	Name         string
	Translations []*locale.Translation
}

func collectServiceEntries(ctx context.Context, company *auth.Company, conn *database.Conn) ([]*serviceEntry, error) {
	rows, err := conn.Query(ctx, `
		select '/admin/services/' || service_id
		     , icon_name
		     , service.name
		     , array_agg((lang_tag, endonym, not exists (select 1 from service_i18n as i18n where i18n.service_id = service.service_id and i18n.lang_tag = language.lang_tag))::translation order by endonym)
		from service
		    join company using (company_id)
		   , language
		where lang_tag <> default_lang_tag
		  and language.selectable
		  and service.company_id = $1
		group by service_id
		       , icon_name
		       , service.name
		order by service.name
	`, pgx.QueryResultFormats{pgx.BinaryFormatCode}, company.ID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var services []*serviceEntry
	for rows.Next() {
		entry := &serviceEntry{}
		var translations database.RecordArray
		if err = rows.Scan(&entry.URL, &entry.Icon, &entry.Name, &translations); err != nil {
			return nil, err
		}
		for _, el := range translations.Elements {
			entry.Translations = append(entry.Translations, &locale.Translation{
				URL:     entry.URL + "/" + el.Fields[0].Get().(string),
				Endonym: el.Fields[1].Get().(string),
				Missing: el.Fields[2].Get().(bool),
			})
		}
		services = append(services, entry)
	}

	return services, nil
}

func addService(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn) {
	f := newServiceForm(r.Context(), conn)
	if ok, err := form.Handle(f, w, r, user); err != nil {
		return
	} else if !ok {
		f.MustRender(w, r, user, company)
		return
	}
	conn.MustExec(r.Context(), "select add_service($1, $2, $3, $4)", company.ID, f.Icon, f.Name, f.Description)
	httplib.Redirect(w, r, "/admin/services", http.StatusSeeOther)
}

func editService(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *serviceForm) {
	if ok, err := form.Handle(f, w, r, user); err != nil {
		return
	} else if !ok {
		f.MustRender(w, r, user, company)
		return
	}
	conn.MustExec(r.Context(), "select edit_service($1, $2, $3, $4)", f.ID, f.Icon, f.Name, f.Description)
	httplib.Redirect(w, r, "/admin/services", http.StatusSeeOther)
}

func deleteService(w http.ResponseWriter, r *http.Request, user *auth.User, conn *database.Conn, id int) {
	if err := user.VerifyCSRFToken(r); err != nil {
		http.Error(w, err.Error(), http.StatusForbidden)
		return
	}
	conn.MustExec(r.Context(), "select remove_service($1)", id)
	httplib.Redirect(w, r, "/admin/services", http.StatusSeeOther)
}

type serviceForm struct {
	ID          int
	Icon        *form.Select
	Name        *form.Input
	Description *form.Input
}

func newServiceForm(ctx context.Context, conn *database.Conn) *serviceForm {
	return &serviceForm{
		Icon: &form.Select{
			Name:    "icon",
			Options: form.MustGetOptions(ctx, conn, "select icon_name, icon_name from icon order by 1"),
		},
		Name: &form.Input{
			Name: "name",
		},
		Description: &form.Input{
			Name: "description",
		},
	}
}

func (f *serviceForm) FillFromDatabase(ctx context.Context, conn *database.Conn, id int) error {
	f.ID = id
	row := conn.QueryRow(ctx, `
		select array[icon_name]
		     , name
		     , description
		from service
		where service_id = $1
	`, id)
	return row.Scan(&f.Icon.Selected, &f.Name.Val, &f.Description.Val)
}

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

func (f *serviceForm) Valid(l *locale.Locale) bool {
	v := form.NewValidator(l)
	v.CheckSelectedOptions(f.Icon, l.GettextNoop("Selected icon is not valid."))
	v.CheckRequired(f.Name, l.GettextNoop("Name can not be empty."))
	return v.AllOK
}

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