package handler

import (
	"net/http"
	"net/http/httptest"
	"testing"

	"codeberg.org/VARASYS/ZDDC/zddc/internal/config"
)

func TestCORSMiddleware(t *testing.T) {
	allowed := config.Config{CORSOrigins: []string{"https://zddc.varasys.io", "https://other.example"}}
	disabled := config.Config{CORSOrigins: nil}

	pass := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	})

	cases := []struct {
		name           string
		cfg            config.Config
		method         string
		origin         string
		acrHeaders     string
		wantStatus     int
		wantAllowOrig  string
		wantAllowCreds string
		wantVary       string
		wantAllowHdrs  string
		wantNextCalled bool
	}{
		{
			name:           "allowed origin, GET",
			cfg:            allowed,
			method:         http.MethodGet,
			origin:         "https://zddc.varasys.io",
			wantStatus:     http.StatusOK,
			wantAllowOrig:  "https://zddc.varasys.io",
			wantAllowCreds: "true",
			wantVary:       "Origin",
			wantNextCalled: true,
		},
		{
			name:           "second allowed origin, GET",
			cfg:            allowed,
			method:         http.MethodGet,
			origin:         "https://other.example",
			wantStatus:     http.StatusOK,
			wantAllowOrig:  "https://other.example",
			wantAllowCreds: "true",
			wantVary:       "Origin",
			wantNextCalled: true,
		},
		{
			name:           "disallowed origin, GET",
			cfg:            allowed,
			method:         http.MethodGet,
			origin:         "https://evil.example",
			wantStatus:     http.StatusOK,
			wantNextCalled: true,
		},
		{
			name:           "no Origin header, GET",
			cfg:            allowed,
			method:         http.MethodGet,
			wantStatus:     http.StatusOK,
			wantNextCalled: true,
		},
		{
			name:           "OPTIONS preflight, allowed origin",
			cfg:            allowed,
			method:         http.MethodOptions,
			origin:         "https://zddc.varasys.io",
			acrHeaders:     "X-Auth-Request-Email, Content-Type",
			wantStatus:     http.StatusNoContent,
			wantAllowOrig:  "https://zddc.varasys.io",
			wantAllowCreds: "true",
			wantVary:       "Origin",
			wantAllowHdrs:  "X-Auth-Request-Email, Content-Type",
			wantNextCalled: false,
		},
		{
			name:           "OPTIONS preflight, disallowed origin falls through",
			cfg:            allowed,
			method:         http.MethodOptions,
			origin:         "https://evil.example",
			wantStatus:     http.StatusOK,
			wantNextCalled: true,
		},
		{
			name:           "CORS disabled passes through",
			cfg:            disabled,
			method:         http.MethodGet,
			origin:         "https://zddc.varasys.io",
			wantStatus:     http.StatusOK,
			wantNextCalled: true,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			called := false
			next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				called = true
				pass.ServeHTTP(w, r)
			})
			h := CORSMiddleware(tc.cfg, next)

			req := httptest.NewRequest(tc.method, "/", nil)
			if tc.origin != "" {
				req.Header.Set("Origin", tc.origin)
			}
			if tc.acrHeaders != "" {
				req.Header.Set("Access-Control-Request-Headers", tc.acrHeaders)
			}
			rec := httptest.NewRecorder()
			h.ServeHTTP(rec, req)

			if rec.Code != tc.wantStatus {
				t.Errorf("status = %d, want %d", rec.Code, tc.wantStatus)
			}
			if got := rec.Header().Get("Access-Control-Allow-Origin"); got != tc.wantAllowOrig {
				t.Errorf("Access-Control-Allow-Origin = %q, want %q", got, tc.wantAllowOrig)
			}
			if got := rec.Header().Get("Access-Control-Allow-Credentials"); got != tc.wantAllowCreds {
				t.Errorf("Access-Control-Allow-Credentials = %q, want %q", got, tc.wantAllowCreds)
			}
			if got := rec.Header().Get("Vary"); got != tc.wantVary {
				t.Errorf("Vary = %q, want %q", got, tc.wantVary)
			}
			if got := rec.Header().Get("Access-Control-Allow-Headers"); got != tc.wantAllowHdrs {
				t.Errorf("Access-Control-Allow-Headers = %q, want %q", got, tc.wantAllowHdrs)
			}
			if called != tc.wantNextCalled {
				t.Errorf("next called = %v, want %v", called, tc.wantNextCalled)
			}
		})
	}
}