// 外部測試套件（package oidc_test）：store 為遷移 OIDC 模型而匯入
// oidc 套件，內部測試套件匯入 testdb（→ store → oidc）會形成循環。
package oidc_test

import (
	"encoding/base64"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"alterminal/internal/jwk"
	"alterminal/internal/oidc"
	"alterminal/internal/testdb"
)

// jwksGet 對 handler 發出 GET /.well-known/jwks.json 並回傳回應記錄器。
func jwksGet(h http.HandlerFunc) *httptest.ResponseRecorder {
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodGet, "/.well-known/jwks.json", nil))
	return rec
}

// mustNewKey 產生一把簽章金鑰；retired 為 true 時標記為已退休。
func mustNewKey(t *testing.T, retired bool) *jwk.SigningKey {
	t.Helper()
	k, err := jwk.NewSigningKey()
	if err != nil {
		t.Fatal("NewSigningKey: ", err)
	}
	if retired {
		now := time.Now()
		k.RetiredAt = &now
	}
	return k
}

func TestJWKSHandlerIntegration(t *testing.T) {
	db := testdb.New(t)

	active1 := mustNewKey(t, false)
	active2 := mustNewKey(t, false)
	retired := mustNewKey(t, true)
	for _, k := range []*jwk.SigningKey{active1, active2, retired} {
		if err := db.Create(k).Error; err != nil {
			t.Fatal("建立測試金鑰: ", err)
		}
	}

	h := oidc.JWKSHandler(db)

	t.Run("僅發佈使用中的金鑰", func(t *testing.T) {
		rec := jwksGet(h)
		if rec.Code != http.StatusOK {
			t.Fatalf("status = %d, want 200, body = %s", rec.Code, rec.Body.String())
		}
		if ct := rec.Header().Get("Content-Type"); ct != "application/json; charset=utf-8" {
			t.Errorf("Content-Type = %q, want application/json; charset=utf-8", ct)
		}
		if cc := rec.Header().Get("Cache-Control"); cc != "public, max-age=3600" {
			t.Errorf("Cache-Control = %q, want public, max-age=3600", cc)
		}
		var set jwk.JWKS
		if err := json.Unmarshal(rec.Body.Bytes(), &set); err != nil {
			t.Fatalf("解析 JWKS: %v", err)
		}
		if len(set.Keys) != 2 {
			t.Fatalf("keys = %d 把, want 2（退休金鑰不應發佈）: %s", len(set.Keys), rec.Body.String())
		}
		kids := map[string]bool{}
		for _, k := range set.Keys {
			kids[k.Kid] = true
			if k.Kty != jwk.KeyTypeRSA || k.Use != jwk.KeyUseSig || k.Alg != jwk.AlgRS256 {
				t.Errorf("kid %s 參數 = kty:%q use:%q alg:%q", k.Kid, k.Kty, k.Use, k.Alg)
			}
			if k.E != "AQAB" {
				t.Errorf("kid %s e = %q, want AQAB", k.Kid, k.E)
			}
			n, err := base64.RawURLEncoding.DecodeString(k.N)
			if err != nil || len(n) == 0 {
				t.Errorf("kid %s 的 n 應為可解碼的非空 base64url: %q (err=%v)", k.Kid, k.N, err)
			}
		}
		if !kids[active1.Kid] || !kids[active2.Kid] {
			t.Errorf("應發佈兩把使用中金鑰 %q、%q，實際 %v", active1.Kid, active2.Kid, kids)
		}
		if kids[retired.Kid] {
			t.Error("退休金鑰不應出現於 JWKS")
		}
	})

	t.Run("GET 為冪等", func(t *testing.T) {
		first, second := jwksGet(h), jwksGet(h)
		if first.Body.String() != second.Body.String() {
			t.Error("兩次 GET 的 JWKS 應相同")
		}
	})
}

// 空資料庫時 keys 為空陣列而非 null（RFC 7517 §5.1：keys 必要）。
func TestJWKSHandlerEmpty(t *testing.T) {
	db := testdb.New(t)
	rec := jwksGet(oidc.JWKSHandler(db))
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200, body = %s", rec.Code, rec.Body.String())
	}
	if s := rec.Body.String(); s != "{\"keys\":[]}\n" && s != `{"keys":[]}` {
		t.Fatalf("空 JWKS 應為 {\"keys\":[]}，得到 %s", s)
	}
}

// 私鑰儲存毀損的金鑰被跳過，其餘金鑰照常發佈。
func TestJWKSHandlerSkipsCorruptKey(t *testing.T) {
	db := testdb.New(t)

	good := mustNewKey(t, false)
	if err := db.Create(good).Error; err != nil {
		t.Fatal("建立測試金鑰: ", err)
	}
	bad := &jwk.SigningKey{Kid: "corrupt-kid", Algorithm: jwk.AlgRS256, PrivateKeyPEM: "not a pem"}
	if err := db.Create(bad).Error; err != nil {
		t.Fatal("建立毀損金鑰: ", err)
	}

	rec := jwksGet(oidc.JWKSHandler(db))
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200, body = %s", rec.Code, rec.Body.String())
	}
	var set jwk.JWKS
	if err := json.Unmarshal(rec.Body.Bytes(), &set); err != nil {
		t.Fatalf("解析 JWKS: %v", err)
	}
	if len(set.Keys) != 1 || set.Keys[0].Kid != good.Kid {
		t.Fatalf("應僅發佈完好的 %q，得到 %s", good.Kid, rec.Body.String())
	}
}