package customer

import (
	"context"
	"net/http"

	"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"
)

type AdminHandler struct {
}

func NewAdminHandler() *AdminHandler {
	return &AdminHandler{}
}

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:
				serveCustomerIndex(w, r, user, company, conn)
			case http.MethodPost:
				addCustomer(w, r, user, company, conn)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPost)
			}
		case "new":
			switch r.Method {
			case http.MethodGet:
				f := newCustomerForm(r.Context(), conn, user.Locale)
				f.MustRender(w, r, user, company)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet)
			}
		default:
			f := newCustomerForm(r.Context(), conn, user.Locale)
			if err := f.FillFromDatabase(r.Context(), conn, head); err != nil {
				if database.ErrorIsNotFound(err) {
					http.NotFound(w, r)
					return
				}
				panic(err)
			}
			h.customerHandler(user, company, conn, f).ServeHTTP(w, r)
		}
	})
}

func (h *AdminHandler) customerHandler(user *auth.User, company *auth.Company, conn *database.Conn, f *customerForm) 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:
				editCustomer(w, r, user, company, conn, f)
			default:
				httplib.MethodNotAllowed(w, r, http.MethodGet, http.MethodPut)
			}
		default:
			http.NotFound(w, r)
		}
	})
}

func serveCustomerIndex(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn) {
	customers, err := collectCustomerEntries(r.Context(), conn, company)
	if err != nil {
		panic(err)
	}
	page := &customerIndex{
		Customers: customers,
	}
	page.MustRender(w, r, user, company)
}

func collectCustomerEntries(ctx context.Context, conn *database.Conn, company *auth.Company) ([]*customerEntry, error) {
	rows, err := conn.Query(ctx, `
		select '/admin/customers/' || slug
		     , name
			 , coalesce(email::text, '')
		     , coalesce(phone::text, '')
		from contact
			left join contact_email using (contact_id)
			left join contact_phone using (contact_id)
		where company_id = $1
		order by name
	`, company.ID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var customers []*customerEntry
	for rows.Next() {
		customer := &customerEntry{}
		if err = rows.Scan(&customer.URL, &customer.Name, &customer.Email, &customer.Phone); err != nil {
			return nil, err
		}
		customers = append(customers, customer)
	}

	return customers, nil
}

type customerEntry struct {
	URL   string
	Name  string
	Email string
	Phone string
}

type customerIndex struct {
	Customers []*customerEntry
}

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

func addCustomer(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn) {
	f := newCustomerForm(r.Context(), conn, user.Locale)
	processCustomerForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		var err error
		f.Slug, err = tx.AddContact(ctx, company.ID, f.FullName.Val, f.IDDocumentType.String(), f.IDDocumentNumber.Val, f.Phone.Val, f.Email.Val, f.Address.Val, f.City.Val, f.Province.Val, f.PostalCode.Val, f.Country.String())
		return err
	})
}

func editCustomer(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *customerForm) {
	processCustomerForm(w, r, user, company, conn, f, func(ctx context.Context, tx *database.Tx) error {
		_, err := tx.EditContact(ctx, f.Slug, f.FullName.Val, f.IDDocumentType.String(), f.IDDocumentNumber.Val, f.Phone.Val, f.Email.Val, f.Address.Val, f.City.Val, f.Province.Val, f.PostalCode.Val, f.Country.String())
		return err
	})
}

func processCustomerForm(w http.ResponseWriter, r *http.Request, user *auth.User, company *auth.Company, conn *database.Conn, f *customerForm, act func(ctx context.Context, tx *database.Tx) error) {
	if err := f.Parse(r); 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
	}
	if ok, err := f.Valid(r.Context(), conn, user.Locale); err != nil {
		panic(err)
	} else if !ok {
		if !httplib.IsHTMxRequest(r) {
			w.WriteHeader(http.StatusUnprocessableEntity)
		}
		f.MustRender(w, r, user, company)
		return
	}

	tx := conn.MustBegin(r.Context())
	if err := act(r.Context(), tx); err == nil {
		if err := tx.Commit(r.Context()); err != nil {
			panic(err)
		}
	} else {
		if err := tx.Rollback(r.Context()); err != nil {
			panic(err)
		}
		panic(err)
	}
	httplib.Redirect(w, r, "/admin/customers", http.StatusSeeOther)
}

type customerForm struct {
	URL              string
	Slug             string
	FullName         *form.Input
	IDDocumentType   *form.Select
	IDDocumentNumber *form.Input
	Address          *form.Input
	City             *form.Input
	Province         *form.Input
	PostalCode       *form.Input
	Country          *form.Select
	Email            *form.Input
	Phone            *form.Input
}

func newCustomerForm(ctx context.Context, conn *database.Conn, l *locale.Locale) *customerForm {
	return &customerForm{
		FullName: &form.Input{
			Name: "full_name",
		},
		IDDocumentType: &form.Select{
			Name:    "id_document_type",
			Options: form.MustGetDocumentTypeOptions(ctx, conn, l),
		},
		IDDocumentNumber: &form.Input{
			Name: "id_document_number",
		},
		Address: &form.Input{
			Name: "address",
		},
		City: &form.Input{
			Name: "city",
		},
		Province: &form.Input{
			Name: "province",
		},
		PostalCode: &form.Input{
			Name: "postal_code",
		},
		Country: &form.Select{
			Name:    "country",
			Options: form.MustGetCountryOptions(ctx, conn, l),
		},
		Email: &form.Input{
			Name: "email",
		},
		Phone: &form.Input{
			Name: "phone",
		},
	}
}

func (f *customerForm) FillFromDatabase(ctx context.Context, conn *database.Conn, slug string) error {
	row := conn.QueryRow(ctx, `
		select '/admin/customers/' || slug
		     , slug
		     , name
		     , array[id_document_type_id::text]
		     , id_document_number
		     , address
		     , city
		     , province
		     , postal_code
		     , array[country_code::text]
		     , coalesce(email::text, '')
		     , coalesce(phone::text, '')
		from contact as text
			left join contact_email using (contact_id)
			left join contact_phone using (contact_id)
		where slug = $1
	`, slug)
	return row.Scan(
		&f.URL,
		&f.Slug,
		&f.FullName.Val,
		&f.IDDocumentType.Selected,
		&f.IDDocumentNumber.Val,
		&f.Address.Val,
		&f.City.Val,
		&f.Province.Val,
		&f.PostalCode.Val,
		&f.Country.Selected,
		&f.Email.Val,
		&f.Phone.Val,
	)
}

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

	f.FullName.FillValue(r)
	f.IDDocumentType.FillValue(r)
	f.IDDocumentNumber.FillValue(r)
	f.Address.FillValue(r)
	f.City.FillValue(r)
	f.Province.FillValue(r)
	f.PostalCode.FillValue(r)
	f.Country.FillValue(r)
	f.Email.FillValue(r)
	f.Phone.FillValue(r)
	return nil
}

func (f *customerForm) Valid(ctx context.Context, conn *database.Conn, l *locale.Locale) (bool, error) {
	v := form.NewValidator(l)

	var country string
	if v.CheckSelectedOptions(f.Country, l.GettextNoop("Selected country is not valid.")) {
		country = f.Country.Selected[0]
	}

	v.CheckSelectedOptions(f.IDDocumentType, l.GettextNoop("Selected ID document type is not valid."))
	v.CheckRequired(f.IDDocumentNumber, l.GettextNoop("ID document number can not be empty."))

	if v.CheckRequired(f.FullName, l.GettextNoop("Full name can not be empty.")) {
		v.CheckMinLength(f.FullName, 1, l.GettextNoop("Full name must have at least one letter."))
	}

	v.CheckRequired(f.Address, l.GettextNoop("Address can not be empty."))
	v.CheckRequired(f.City, l.GettextNoop("Town or village can not be empty."))
	if v.CheckRequired(f.PostalCode, l.GettextNoop("Postcode can not be empty.")) && country != "" {
		if _, err := v.CheckValidPostalCode(ctx, conn, f.PostalCode, country, l.GettextNoop("This postcode is not valid.")); err != nil {
			return false, err
		}
	}
	if f.Email.Val != "" {
		v.CheckValidEmail(f.Email, l.GettextNoop("This email is not valid. It should be like name@domain.com."))
	}
	if f.Phone.Val != "" && country != "" {
		if _, err := v.CheckValidPhone(ctx, conn, f.Phone, country, l.GettextNoop("This phone number is not valid.")); err != nil {
			return false, err
		}
	}
	return v.AllOK, nil
}

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