package site

import (
	"context"

	"github.com/google/uuid"
)

type Service struct {
	repo Repository
}

func NewService(repo Repository) *Service {
	return &Service{repo: repo}
}

func (s *Service) Get(ctx context.Context) (*Settings, error) {
	return s.repo.Get(ctx)
}

func (s *Service) Update(ctx context.Context, name, description string, ordersEnabled bool) (*Settings, error) {
	settings := &Settings{Name: name, Description: description, OrdersEnabled: ordersEnabled}
	if err := s.repo.Update(ctx, settings); err != nil {
		return nil, err
	}
	return s.repo.Get(ctx)
}

// AppearanceInput is updated independently from site identity (name/slug):
// the "Appearance" admin page only ever touches these fields, so it must
// not be blocked by identity validation (e.g. an unset slug) or clobber
// name/description/slug on save. Each field is a pointer so the admin can
// change a single option (e.g. just the product layout) without resending
// every color -- nil fields keep their current, already-saved value.
type AppearanceInput struct {
	HeaderBgColor   *string
	HeaderTextColor *string
	BodyBgColor     *string
	BodyTextColor   *string
	FooterBgColor   *string
	FooterTextColor *string
	AccentColor     *string
	ProductLayout   *string
	ProductColumns  *int
	ProductScroll   *string

	ContactCardTransparent *bool
	ContactCardBgColor     *string

	// LogoMediaIDSet/HeroMediaIDSet distinguish "the admin didn't touch
	// this field" (false: keep the current value) from "the admin
	// explicitly chose an image, possibly clearing it to nil" (true: use
	// the ID as-is, nil included) -- same reasoning as
	// CustomerAuthInput.VerificationContactLinkSet.
	LogoMediaIDSet bool
	LogoMediaID    *uuid.UUID
	HeroMediaIDSet bool
	HeroMediaID    *uuid.UUID
	HeroPages      *string
}

func (s *Service) UpdateAppearance(ctx context.Context, in AppearanceInput) (*Settings, error) {
	current, err := s.repo.Get(ctx)
	if err != nil {
		return nil, err
	}

	settings := &Settings{
		HeaderBgColor:          applyIfSet(in.HeaderBgColor, current.HeaderBgColor),
		HeaderTextColor:        applyIfSet(in.HeaderTextColor, current.HeaderTextColor),
		BodyBgColor:            applyIfSet(in.BodyBgColor, current.BodyBgColor),
		BodyTextColor:          applyIfSet(in.BodyTextColor, current.BodyTextColor),
		FooterBgColor:          applyIfSet(in.FooterBgColor, current.FooterBgColor),
		FooterTextColor:        applyIfSet(in.FooterTextColor, current.FooterTextColor),
		AccentColor:            applyIfSet(in.AccentColor, current.AccentColor),
		ProductLayout:          applyIfSet(in.ProductLayout, current.ProductLayout),
		ProductColumns:         applyIntIfSet(in.ProductColumns, current.ProductColumns),
		ProductScroll:          applyIfSet(in.ProductScroll, current.ProductScroll),
		ContactCardTransparent: applyBoolIfSet(in.ContactCardTransparent, current.ContactCardTransparent),
		ContactCardBgColor:     applyIfSet(in.ContactCardBgColor, current.ContactCardBgColor),
		LogoMediaID:            current.LogoMediaID,
		HeroMediaID:            current.HeroMediaID,
		HeroPages:              applyIfSet(in.HeroPages, current.HeroPages),
	}
	if in.LogoMediaIDSet {
		settings.LogoMediaID = in.LogoMediaID
	}
	if in.HeroMediaIDSet {
		settings.HeroMediaID = in.HeroMediaID
	}
	if err := s.repo.UpdateAppearance(ctx, settings); err != nil {
		return nil, err
	}
	return s.repo.Get(ctx)
}

func applyIfSet(value *string, fallback string) string {
	if value == nil {
		return fallback
	}
	return *value
}

func applyIntIfSet(value *int, fallback int) int {
	if value == nil {
		return fallback
	}
	return *value
}

// CustomerAuthInput is updated independently from identity/appearance, same
// reasoning as AppearanceInput: the "Customer accounts" admin page only
// ever touches these fields. LoginEnabled and RegistrationEnabled are two
// independent switches (e.g. an invite-only shop can enable login while
// keeping registration off), so each is its own optional pointer.
type CustomerAuthInput struct {
	LoginEnabled         *bool
	RegistrationEnabled  *bool
	VerificationRequired *bool
	// VerificationContactLinkSet distinguishes "the admin didn't touch this
	// field" (false: keep the current value) from "the admin explicitly
	// chose a link, possibly clearing it to nil" (true: use
	// VerificationContactLinkID as-is, nil included).
	VerificationContactLinkSet bool
	VerificationContactLinkID  *uuid.UUID
}

func (s *Service) UpdateCustomerAuth(ctx context.Context, in CustomerAuthInput) (*Settings, error) {
	current, err := s.repo.Get(ctx)
	if err != nil {
		return nil, err
	}

	settings := &Settings{
		CustomerLoginEnabled:         applyBoolIfSet(in.LoginEnabled, current.CustomerLoginEnabled),
		CustomerRegistrationEnabled:  applyBoolIfSet(in.RegistrationEnabled, current.CustomerRegistrationEnabled),
		CustomerVerificationRequired: applyBoolIfSet(in.VerificationRequired, current.CustomerVerificationRequired),
		VerificationContactLinkID:    current.VerificationContactLinkID,
	}
	if in.VerificationContactLinkSet {
		settings.VerificationContactLinkID = in.VerificationContactLinkID
	}
	if err := s.repo.UpdateCustomerAuth(ctx, settings); err != nil {
		return nil, err
	}
	return s.repo.Get(ctx)
}

func applyBoolIfSet(value *bool, fallback bool) bool {
	if value == nil {
		return fallback
	}
	return *value
}

// CustomerLoginEnabled is consumed by auth.CustomerHandler to gate the
// customer login page/endpoint behind the admin's toggle.
func (s *Service) CustomerLoginEnabled(ctx context.Context) (bool, error) {
	settings, err := s.repo.Get(ctx)
	if err != nil {
		return false, err
	}
	return settings.CustomerLoginEnabled, nil
}

// CustomerRegistrationEnabled is consumed by auth.CustomerHandler to gate
// the customer registration page/endpoint behind the admin's toggle,
// independently of CustomerLoginEnabled.
func (s *Service) CustomerRegistrationEnabled(ctx context.Context) (bool, error) {
	settings, err := s.repo.Get(ctx)
	if err != nil {
		return false, err
	}
	return settings.CustomerRegistrationEnabled, nil
}

// CustomerAccountsAvailable is consumed by users.Service.Create to prevent
// creating customer-role users when neither login nor registration is
// enabled -- such an account could never be used to sign in.
func (s *Service) CustomerAccountsAvailable(ctx context.Context) (bool, error) {
	settings, err := s.repo.Get(ctx)
	if err != nil {
		return false, err
	}
	return settings.CustomerLoginEnabled || settings.CustomerRegistrationEnabled, nil
}

// CustomerCheckoutSettings is consumed by orders.RequireAccountsEnabled /
// RequireApprovedVerificationIfNeeded to gate order creation.
func (s *Service) CustomerCheckoutSettings(ctx context.Context) (accountsEnabled, verificationRequired bool, err error) {
	settings, err := s.repo.Get(ctx)
	if err != nil {
		return false, false, err
	}
	return settings.CustomerLoginEnabled, settings.CustomerVerificationRequired, nil
}

// OrdersEnabled is consumed by orders.RequireOrdersEnabled: the site-wide
// "vitrine vs boutique" switch, checked before any of the customer-account
// gates so a pure showcase site never has to think about accounts at all.
func (s *Service) OrdersEnabled(ctx context.Context) (bool, error) {
	settings, err := s.repo.Get(ctx)
	if err != nil {
		return false, err
	}
	return settings.OrdersEnabled, nil
}