package pkg

import (
	"context"
	"github.com/jackc/pgtype"
	"github.com/julienschmidt/httprouter"
	"html/template"
	"net/http"
	"time"
)

const (
	ExpirationDateFormat = "01/06"
	AccountTypeBank      = "bank"
	AccountTypeCard      = "card"
	AccountTypeCash      = "cash"
	AccountTypeOther     = "other"
)

func servePaymentAccountIndex(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
	conn := getConn(r)
	locale := getLocale(r)

	page := NewPaymentAccountIndexPage(r.Context(), conn, locale)
	page.MustRender(w, r)
}

type PaymentAccountIndexPage struct {
	Accounts []*PaymentAccountEntry
}

func NewPaymentAccountIndexPage(ctx context.Context, conn *Conn, locale *Locale) *PaymentAccountIndexPage {
	return &PaymentAccountIndexPage{
		Accounts: mustCollectPaymentAccountEntries(ctx, conn, locale),
	}
}

func (page *PaymentAccountIndexPage) MustRender(w http.ResponseWriter, r *http.Request) {
	mustRenderMainTemplate(w, r, "payments/accounts/index.gohtml", page)
}

type PaymentAccountEntry struct {
	ID             int
	Slug           string
	Type           string
	TypeLabel      string
	Name           string
	IBAN           string
	LastFourDigits string
	ExpirationDate string
}

func mustCollectPaymentAccountEntries(ctx context.Context, conn *Conn, locale *Locale) []*PaymentAccountEntry {
	rows := conn.MustQuery(ctx, `
		select payment_account_id
		     , slug
		     , payment_account.payment_account_type
		     , coalesce(i18n.name, payment_account_type.name)
		     , payment_account.name
		     , coalesce(iban::text, '') as iban
		     , coalesce(last_four_digits, '') as last_four_digits
		     , expiration_date
		from payment_account
		    left join payment_account_bank using (payment_account_id, payment_account_type)
		    left join payment_account_card using (payment_account_id, payment_account_type)
		join payment_account_type using (payment_account_type)
		left join payment_account_type_i18n as i18n on payment_account_type.payment_account_type = i18n.payment_account_type and i18n.lang_tag = $1
		order by payment_account_id
	`, locale.Language.String())
	defer rows.Close()

	var entries []*PaymentAccountEntry
	for rows.Next() {
		entry := &PaymentAccountEntry{}
		var expirationDate pgtype.Date
		if err := rows.Scan(&entry.ID, &entry.Slug, &entry.Type, &entry.TypeLabel, &entry.Name, &entry.IBAN, &entry.LastFourDigits, &expirationDate); err != nil {
			panic(err)
		}
		if expirationDate.Status == pgtype.Present {
			entry.ExpirationDate = expirationDate.Time.Format(ExpirationDateFormat)
		}
		entries = append(entries, entry)
	}
	if rows.Err() != nil {
		panic(rows.Err())
	}

	return entries
}

func servePaymentAccountForm(w http.ResponseWriter, r *http.Request, params httprouter.Params) {
	locale := getLocale(r)
	conn := getConn(r)
	company := mustGetCompany(r)
	form := newPaymentAccountForm(r.Context(), conn, locale, company)
	slug := params[0].Value
	if slug == "new" {
		form.MustRender(w, r)
		return
	}
	if !ValidUuid(slug) {
		http.NotFound(w, r)
		return
	}
	if !form.MustFillFromDatabase(r.Context(), conn, slug) {
		http.NotFound(w, r)
		return
	}
	form.MustRender(w, r)
}

type PaymentAccountForm struct {
	locale              *Locale
	company             *Company
	Slug                string
	Type                *RadioField
	Name                *InputField
	IBAN                *InputField
	LastFourDigits      *InputField
	ExpirationMonthYear *InputField
}

func newPaymentAccountForm(ctx context.Context, conn *Conn, locale *Locale, company *Company) *PaymentAccountForm {
	return &PaymentAccountForm{
		locale:  locale,
		company: company,
		Type: &RadioField{
			Name:     "payment_account_type",
			Label:    pgettext("input", "Type", locale),
			Required: true,
			Options:  MustGetRadioOptions(ctx, conn, "select payment_account_type, i18n.name from payment_account_type join payment_account_type_i18n as i18n using (payment_account_type) where i18n.lang_tag = $1 order by payment_account_type", locale.Language.String()),
			Attributes: []template.HTMLAttr{
				`x-model="type"`,
			},
		},
		Name: &InputField{
			Name:     "name",
			Label:    pgettext("input", "Name", locale),
			Required: true,
			Type:     "text",
		},
		IBAN: &InputField{
			Name:     "iban",
			Label:    pgettext("input", "IBAN", locale),
			Required: true,
			Type:     "text",
		},
		LastFourDigits: &InputField{
			Name:     "last_four_digits",
			Label:    pgettext("input", "Card’s last four digits", locale),
			Required: true,
			Type:     "text",
			Attributes: []template.HTMLAttr{
				`maxlength="4"`,
				`minlength="4"`,
				`pattern="[0-9]{4}"`,
			},
		},
		ExpirationMonthYear: &InputField{
			Name:     "expiration_date",
			Label:    pgettext("input", "Expiration date", locale),
			Required: true,
			Type:     "text",
			Attributes: []template.HTMLAttr{
				`maxlength="5"`,
				`minlength="5"`,
				`pattern="[0-9]{2}/[0-9]{2}"`,
			},
		},
	}
}

func (f *PaymentAccountForm) MustRender(w http.ResponseWriter, r *http.Request) {
	if f.Slug == "" {
		mustRenderMainTemplate(w, r, "payments/accounts/new.gohtml", f)
	} else {
		mustRenderMainTemplate(w, r, "payments/accounts/edit.gohtml", f)
	}
}

func (f *PaymentAccountForm) MustFillFromDatabase(ctx context.Context, conn *Conn, slug string) bool {
	selectedType := f.Type.Selected
	var expirationDate pgtype.Date
	if notFoundErrorOrPanic(conn.QueryRow(ctx, `
		select payment_account_type
		     , name
		     , coalesce(iban::text, '') as iban
		     , coalesce(last_four_digits, '') as last_four_digits
		     , expiration_date
		from payment_account
		left join payment_account_bank using (payment_account_id, payment_account_type)
		left join payment_account_card using (payment_account_id, payment_account_type)
		where slug = $1
	`, slug).Scan(
		f.Type,
		f.Name,
		f.IBAN,
		f.LastFourDigits,
		&expirationDate)) {
		f.Type.Selected = selectedType
		return false
	}
	f.Slug = slug
	if expirationDate.Status == pgtype.Present {
		f.ExpirationMonthYear.Val = expirationDate.Time.Format(ExpirationDateFormat)
	} else {
		f.ExpirationMonthYear.Val = ""
	}
	return true
}

func (f *PaymentAccountForm) Parse(r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		return err
	}
	f.Type.FillValue(r)
	f.Name.FillValue(r)
	f.IBAN.FillValue(r)
	f.LastFourDigits.FillValue(r)
	f.ExpirationMonthYear.FillValue(r)
	return nil
}

func (f *PaymentAccountForm) Validate(ctx context.Context, conn *Conn) bool {
	validator := newFormValidator()

	if validator.CheckValidRadioOption(f.Type, gettext("Selected payment account type is not valid.", f.locale)) {
		switch f.Type.Selected {
		case AccountTypeBank:
			if validator.CheckRequiredInput(f.IBAN, gettext("IBAN can not be empty.", f.locale)) {
				validator.CheckValidIBANInput(ctx, conn, f.IBAN, gettext("This value is not a valid IBAN.", f.locale))
			}
		case AccountTypeCard:
			if validator.CheckRequiredInput(f.LastFourDigits, gettext("Last four digits can not be empty.", f.locale)) {
				if validator.CheckInputLength(f.LastFourDigits, 4, gettext("You must enter the card’s last four digits", f.locale)) {
					validator.CheckValidInteger(f.LastFourDigits, 0, 9999, gettext("Last four digits must be a number.", f.locale))
				}
			}
			if validator.CheckRequiredInput(f.ExpirationMonthYear, gettext("Expiration date can not be empty.", f.locale)) {
				_, err := time.Parse(ExpirationDateFormat, f.ExpirationMonthYear.Val)
				validator.checkInput(f.ExpirationMonthYear, err == nil, gettext("Expiration date should be a valid date in format MM/YY (e.g., 08/24).", f.locale))
			}
		}
	}
	validator.CheckRequiredInput(f.Name, gettext("Payment account name can not be empty.", f.locale))

	return validator.AllOK()
}

func (f *PaymentAccountForm) ExpirationDate() (time.Time, error) {
	date, err := time.Parse(ExpirationDateFormat, f.ExpirationMonthYear.Val)
	if err != nil {
		return date, err
	}
	return date.AddDate(0, 1, -1), nil
}

func handleAddPaymentAccount(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
	locale := getLocale(r)
	conn := getConn(r)
	company := mustGetCompany(r)
	form := newPaymentAccountForm(r.Context(), conn, locale, company)
	if err := form.Parse(r); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if err := verifyCsrfTokenValid(r); err != nil {
		http.Error(w, err.Error(), http.StatusForbidden)
		return
	}
	if !form.Validate(r.Context(), conn) {
		if !IsHTMxRequest(r) {
			w.WriteHeader(http.StatusUnprocessableEntity)
		}
		form.MustRender(w, r)
		return
	}
	switch form.Type.Selected {
	case AccountTypeBank:
		conn.MustExec(r.Context(), "select add_payment_account_bank($1, $2, $3)", company.Id, form.Name, form.IBAN)
	case AccountTypeCard:
		date, err := form.ExpirationDate()
		if err != nil {
			panic(err)
		}
		conn.MustExec(r.Context(), "select add_payment_account_card($1, $2, $3, $4)", company.Id, form.Name, form.LastFourDigits, date)
	case AccountTypeCash:
		conn.MustExec(r.Context(), "select add_payment_account_cash($1, $2)", company.Id, form.Name)
	case AccountTypeOther:
		conn.MustExec(r.Context(), "select add_payment_account_other($1, $2)", company.Id, form.Name)
	}
	htmxRedirect(w, r, companyURI(company, "/payment-accounts"))
}

func handleEditPaymentAccount(w http.ResponseWriter, r *http.Request, params httprouter.Params) {
	conn := getConn(r)
	locale := getLocale(r)
	company := mustGetCompany(r)
	form := newPaymentAccountForm(r.Context(), conn, locale, company)
	form.Slug = params[0].Value
	if !ValidUuid(form.Slug) {
		http.NotFound(w, r)
		return
	}
	if err := form.Parse(r); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if err := verifyCsrfTokenValid(r); err != nil {
		http.Error(w, err.Error(), http.StatusForbidden)
		return
	}
	if !form.Validate(r.Context(), conn) {
		if !IsHTMxRequest(r) {
			w.WriteHeader(http.StatusUnprocessableEntity)
		}
		form.MustRender(w, r)
		return
	}
	var found string
	switch form.Type.Selected {
	case AccountTypeBank:
		found = conn.MustGetText(r.Context(), "", "select edit_payment_account_bank($1, $2, $3)", form.Slug, form.Name, form.IBAN)
	case AccountTypeCard:
		date, err := form.ExpirationDate()
		if err != nil {
			panic(err)
		}
		found = conn.MustGetText(r.Context(), "", "select edit_payment_account_card($1, $2, $3, $4)", form.Slug, form.Name, form.LastFourDigits, date)
	case AccountTypeCash:
		found = conn.MustGetText(r.Context(), "", "select edit_payment_account_cash($1, $2)", form.Slug, form.Name)
	case AccountTypeOther:
		found = conn.MustGetText(r.Context(), "", "select edit_payment_account_other($1, $2)", form.Slug, form.Name)
	}
	if found == "" {
		http.NotFound(w, r)
		return
	}
	htmxRedirect(w, r, companyURI(company, "/payment-accounts"))
}