package platform

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestFetchOAuthConfig_Success(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/auth/config" {
			t.Errorf("path = %s, want /api/auth/config", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{
			"auth_mode":     "prod",
			"authorize_url": "https://casdoor.example/login/oauth/authorize",
			"token_url":     "https://casdoor.example/api/login/oauth/access_token",
			"client_id":     "web-client-id",
			"redirect_uri":  "https://drop.example/oauth/callback",
			"scopes":        "openid profile groups",
		})
	}))
	defer srv.Close()

	// trailing slash on apiBase must be tolerated
	cfg, err := FetchOAuthConfig(context.Background(), srv.URL+"/")
	if err != nil {
		t.Fatalf("FetchOAuthConfig: %v", err)
	}
	if cfg.ClientID != "web-client-id" {
		t.Errorf("client_id = %q, want web-client-id (reused web client)", cfg.ClientID)
	}
	if cfg.TokenURL != "https://casdoor.example/api/login/oauth/access_token" {
		t.Errorf("token_url = %q", cfg.TokenURL)
	}
	if cfg.Scopes != "openid profile groups" {
		t.Errorf("scopes = %q", cfg.Scopes)
	}
}

func TestFetchOAuthConfig_Incomplete(t *testing.T) {
	// backend missing token_url / client_id (e.g. dev mode) must be rejected.
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{
			"auth_mode":     "dev",
			"authorize_url": "https://casdoor.example/login/oauth/authorize",
		})
	}))
	defer srv.Close()

	if _, err := FetchOAuthConfig(context.Background(), srv.URL); err == nil {
		t.Fatal("want error for incomplete backend config, got nil")
	}
}

func TestFetchOAuthConfig_BadStatus(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer srv.Close()

	if _, err := FetchOAuthConfig(context.Background(), srv.URL); err == nil {
		t.Fatal("want error for 500 status, got nil")
	}
}