// Copyright © 2023 Ory Corp
// SPDX-License-Identifier: Apache-2.0

package oidc

import (
	"context"
	"fmt"
	"net/url"
	"slices"

	"github.com/ory/kratos/x"

	"github.com/bwmarrin/discordgo"
	"github.com/pkg/errors"
	"golang.org/x/oauth2"

	"github.com/ory/herodot"

	"github.com/ory/x/stringsx"
)

var _ OAuth2Provider = (*ProviderDiscord)(nil)

type ProviderDiscord struct {
	config *Configuration
	reg    Dependencies
}

func NewProviderDiscord(
	config *Configuration,
	reg Dependencies,
) Provider {
	return &ProviderDiscord{
		config: config,
		reg:    reg,
	}
}

func (d *ProviderDiscord) Config() *Configuration {
	return d.config
}

func (d *ProviderDiscord) oauth2(ctx context.Context) *oauth2.Config {
	return &oauth2.Config{
		ClientID:     d.config.ClientID,
		ClientSecret: d.config.ClientSecret,
		Endpoint: oauth2.Endpoint{
			AuthURL:  discordgo.EndpointOauth2 + "authorize",
			TokenURL: discordgo.EndpointOauth2 + "token",
		},
		RedirectURL: d.config.Redir(d.reg.Config().OIDCRedirectURIBase(ctx)),
		Scopes:      d.config.Scope,
	}
}

func (d *ProviderDiscord) OAuth2(ctx context.Context) (*oauth2.Config, error) {
	return d.oauth2(ctx), nil
}

func (d *ProviderDiscord) AuthCodeURLOptions(r ider) []oauth2.AuthCodeOption {
	if isForced(r) {
		return []oauth2.AuthCodeOption{
			oauth2.SetAuthURLParam("prompt", "consent"),
		}
	}
	return []oauth2.AuthCodeOption{
		oauth2.SetAuthURLParam("prompt", "none"),
	}
}

func (d *ProviderDiscord) Claims(ctx context.Context, exchange *oauth2.Token, query url.Values) (*Claims, error) {
	grantedScopes := stringsx.Splitx(fmt.Sprintf("%s", exchange.Extra("scope")), " ")
	for _, check := range d.Config().Scope {
		if !slices.Contains(grantedScopes, check) {
			return nil, errors.WithStack(ErrScopeMissing())
		}
	}

	dg, err := discordgo.New(fmt.Sprintf("Bearer %s", exchange.AccessToken))
	if err != nil {
		return nil, errors.WithStack(herodot.ErrInternalServerError().WithReasonf("%s", err))
	}

	user, err := dg.User("@me")
	if err != nil {
		return nil, errors.WithStack(herodot.ErrUpstreamError().WithWrap(err).WithReasonf("%s", err))
	}

	claims := &Claims{
		Issuer:            discordgo.EndpointOauth2,
		Subject:           user.ID,
		Name:              fmt.Sprintf("%s#%s", user.Username, user.Discriminator),
		Nickname:          user.Username,
		PreferredUsername: user.Username,
		Picture:           user.AvatarURL(""),
		Email:             user.Email,
		EmailVerified:     x.ConvertibleBoolean(user.Verified),
		Locale:            Locale(user.Locale),
	}

	return claims, nil
}