/*
 * 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 {
	carousel *carousel.AdminHandler
}

func NewAdminHandler() *AdminHandler {
	return &AdminHandler{
		carousel: carousel.NewAdminHandler(carouselName, serveServicesIndex),
	}
}

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:
				serveServicesIndex(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, company)
				f.MustRender(w, r, user, company)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet)
			}
		case "order":
			switch r.Method {
			case http.MethodPost:
				orderServices(w, r, user, company, conn)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodPost)
			}
		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, company)
			if err := f.FillFromDatabase(r.Context(), conn, id); err != nil {
				if database.ErrorIsNotFound(err) {
					http.NotFound(w, r)
					return
				}
				panic(err)
			}

			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:
					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:
				http.NotFound(w, r)
			}
		}
	})
}

func orderServices(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn) {
	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["service_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.OrderServices(r.Context(), ids); err != nil {
			panic(err)
		}
	}
	serveServicesIndex(w, r, user, company, conn)
}

func serveServicesIndex(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)
	if err != nil {
		panic(err)
	}
	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 {
	ID   int
	URL  string
	Icon string
	Name string
}

func collectServiceEntries(ctx context.Context, company *auth.Company, conn *database.Conn) ([]*serviceEntry, error) {
	rows, err := conn.Query(ctx, `
		select service_id
		     , '/admin/services/' || service_id
		     , icon_name
		     , name
		from service
		where company_id = $1
		order by position
		       , name
	`, company.ID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var services []*serviceEntry
	for rows.Next() {
		entry := &serviceEntry{}
		if err = rows.Scan(&entry.ID, &entry.URL, &entry.Icon, &entry.Name); err != nil {
			return nil, err
		}
		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, company)
	processServiceForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		var err error
		if f.ID, err = tx.AddService(ctx, company.ID, f.Icon.String(), f.Name[f.DefaultLang].Val, f.Description[f.DefaultLang].Val); err != nil {
			return err
		}
		return translateService(ctx, tx, company, f)
	})
}

func processServiceForm(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *serviceForm, act func(context.Context, *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())
	if err := act(r.Context(), tx); err == nil {
		tx.MustCommit(r.Context())
	} else {
		if rErr := tx.Rollback(r.Context()); rErr != nil {
			err = rErr
		}
		panic(err)
	}
	httplib.Redirect(w, r, "/admin/services", http.StatusSeeOther)
}

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

func editService(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *serviceForm) {
	processServiceForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		if err := tx.EditService(ctx, f.ID, f.Icon.String(), f.Name[f.DefaultLang].Val, f.Description[f.DefaultLang].Val); err != nil {
			return err
		}
		return translateService(ctx, tx, company, f)
	})
	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 {
	DefaultLang string
	ID          int
	Icon        *form.Select
	Name        form.I18nInput
	Description form.I18nInput
}

func newServiceForm(ctx context.Context, conn *database.Conn, company *auth.Company) *serviceForm {
	return &serviceForm{
		DefaultLang: company.DefaultLanguage.String(),
		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"),
		Description: form.NewI18nInput(company.Locales, "description"),
	}
}

func (f *serviceForm) FillFromDatabase(ctx context.Context, conn *database.Conn, id int) error {
	f.ID = id
	var name database.RecordArray
	var description database.RecordArray
	row := conn.QueryRow(ctx, `
		select array[icon_name]
		     , service.name
		     , service.description::text
		     , array_agg((lang_tag, i18n.name))
		     , array_agg((lang_tag, i18n.description::text))
		from service
		left join service_i18n as i18n using (service_id)
		where service_id = $1
		group by icon_name
		       , service.name
		       , service.description::text
	`, pgx.QueryResultFormats{pgx.BinaryFormatCode}, id)
	if err := row.Scan(&f.Icon.Selected, &f.Name[f.DefaultLang].Val, &f.Description[f.DefaultLang].Val, &name, &description); err != nil {
		return err
	}
	if err := f.Name.FillArray(name); err != nil {
		return err
	}
	if err := f.Description.FillArray(description); err != nil {
		return err
	}
	return nil
}

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[f.DefaultLang], 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)
}