//go:build test
// +build test

package auth

// Package auth contains tests for JWT generation, verification, and JTI revocation.
//
// Test Coverage:
//   - generateJTI: UUID v4 format validation, uniqueness
//   - GenerateToken: returns non-empty token and JTI, JTI matches claim
//   - VerifyToken: returns correct user_id/role/JTI, rejects revoked/missing JTI
//   - RevokeJTI: adds to revoked set, IsJTIRevoked reflects changes
//   - CleanupRevokedJTIs: removes expired JTIs, keeps valid ones

import (
	"context"
	"strings"
	"testing"
	"time"

	"crussell/db"
)

// requiresDB skips the test if the database is not available (e.g. running
// tests standalone without test DB setup). DB-backed JTI revocation tests
// need a connection to the revoked_jtis table.
func requiresDB(t *testing.T) {
	t.Helper()
	if db.DB == nil {
		t.Skip("skipping: no database connection")
	}
}

// =============================================================================
// generateJTI Tests
// =============================================================================

// TestGenerateJTI_Format verifies that generateJTI returns a valid UUID v4 string
// in the format: 8-4-4-4-12 hexadecimal digits with version and variant bits set.
func TestGenerateJTI_Format(t *testing.T) {
	jti, err := generateJTI()
	if err != nil {
		t.Fatalf("generateJTI() failed: %v", err)
	}

	// UUID v4 format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
	parts := strings.Split(jti, "-")
	if len(parts) != 5 {
		t.Errorf("expected 5 parts in UUID, got %d: %s", len(parts), jti)
	}

	// Check each part length: 8-4-4-4-12
	expectedLengths := []int{8, 4, 4, 4, 12}
	for i, part := range parts {
		if len(part) != expectedLengths[i] {
			t.Errorf("part %d expected length %d, got %d (jti=%s)", i, expectedLengths[i], len(part), jti)
		}
	}

	// Check version nibble (4xxx) in the third group
	if len(parts[2]) > 0 && parts[2][0] != '4' {
		t.Errorf("expected version 4 UUID, got version %c in jti=%s", parts[2][0], jti)
	}

	// Check variant bits (8xxx, 9xxx, axxx, or bxxx) in the fourth group
	if len(parts[3]) > 0 {
		c := parts[3][0]
		if c != '8' && c != '9' && c != 'a' && c != 'b' {
			t.Errorf("expected variant bits 10xx, got %c in jti=%s", c, jti)
		}
	}
}

// TestGenerateJTI_Unique generates 100 JTIs and verifies all are unique.
func TestGenerateJTI_Unique(t *testing.T) {
	seen := make(map[string]bool)
	for i := 0; i < 100; i++ {
		jti, err := generateJTI()
		if err != nil {
			t.Fatalf("generateJTI() failed at iteration %d: %v", i, err)
		}
		if seen[jti] {
			t.Errorf("duplicate JTI generated at iteration %d: %s", i, jti)
		}
		seen[jti] = true
	}

	if len(seen) != 100 {
		t.Errorf("expected 100 unique JTIs, got %d", len(seen))
	}
}

// =============================================================================
// GenerateToken Tests
// =============================================================================

// TestGenerateToken_ReturnsJTI verifies that GenerateToken returns both a
// non-empty token string and a non-empty JTI string.
func TestGenerateToken_ReturnsJTI(t *testing.T) {
	token, jti, err := GenerateToken("user-001", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}
	if token == "" {
		t.Error("expected non-empty token")
	}
	if jti == "" {
		t.Error("expected non-empty JTI")
	}
}

// TestGenerateToken_JTIInClaims decodes the generated token and verifies
// the "jti" claim matches the returned JTI value.
func TestGenerateToken_JTIInClaims(t *testing.T) {
	token, jti, err := GenerateToken("user-002", "admin")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	decoded, err := TokenAuth.Decode(token)
	if err != nil {
		t.Fatalf("failed to decode token: %v", err)
	}

	var claimJTI string
	if err := decoded.Get("jti", &claimJTI); err != nil {
		t.Fatalf("failed to get jti claim: %v", err)
	}

	if claimJTI != jti {
		t.Errorf("expected jti claim %q, got %q", jti, claimJTI)
	}
}

// =============================================================================
// VerifyToken Tests
// =============================================================================

// TestVerifyToken_ReturnsJTI creates a token, verifies it, and checks the
// returned user_id, role, and JTI match the expected values.
func TestVerifyToken_ReturnsJTI(t *testing.T) {
	token, jti, err := GenerateToken("user-003", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	userID, role, returnedJTI, err := VerifyToken(token, context.Background())
	if err != nil {
		t.Fatalf("VerifyToken() failed: %v", err)
	}

	if userID != "user-003" {
		t.Errorf("expected userID 'user-003', got %q", userID)
	}
	if role != "verified_email" {
		t.Errorf("expected role 'verified_email', got %q", role)
	}
	if returnedJTI != jti {
		t.Errorf("expected JTI %q, got %q", jti, returnedJTI)
	}
}

// TestVerifyToken_RevokedJTI creates a token, revokes its JTI, and verifies
// that VerifyToken returns an error containing "token revoked".
func TestVerifyToken_RevokedJTI(t *testing.T) {
	requiresDB(t)
	token, jti, err := GenerateToken("user-004", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	RevokeJTI(jti, time.Now().Add(30*24*time.Hour))

	_, _, _, err = VerifyToken(token, context.Background())
	if err == nil {
		t.Fatal("expected error for revoked JTI, got nil")
	}
	if !strings.Contains(err.Error(), "token revoked") {
		t.Errorf("expected 'token revoked' error, got: %v", err)
	}
}

// TestVerifyToken_MissingJTI creates a token without a "jti" claim (using
// TokenAuth.Encode directly) and verifies that VerifyToken returns an error
// containing "invalid jti claim".
func TestVerifyToken_MissingJTI(t *testing.T) {
	_, tokenString, err := TokenAuth.Encode(map[string]interface{}{
		"user_id": "user-005",
		"role":    "verified_email",
		"exp":     time.Now().Add(30 * 24 * time.Hour).Unix(),
	})
	if err != nil {
		t.Fatalf("failed to create token without JTI: %v", err)
	}

	_, _, _, err = VerifyToken(tokenString, context.Background())
	if err == nil {
		t.Fatal("expected error for missing JTI, got nil")
	}
	if !strings.Contains(err.Error(), "invalid jti claim") {
		t.Errorf("expected 'invalid jti claim' error, got: %v", err)
	}
}

// =============================================================================
// RevokeJTI / IsJTIRevoked Tests
// =============================================================================

// TestRevokeJTI_AddsToSet verifies that calling RevokeJTI adds the JTI to the
// revoked set, and IsJTIRevoked returns true for it.
func TestRevokeJTI_AddsToSet(t *testing.T) {
	requiresDB(t)
	_, jti, err := GenerateToken("user-006", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	if IsJTIRevoked(jti) {
		t.Fatal("JTI should not be revoked before calling RevokeJTI")
	}

	RevokeJTI(jti, time.Now().Add(30*24*time.Hour))

	if !IsJTIRevoked(jti) {
		t.Error("expected IsJTIRevoked to return true after RevokeJTI")
	}
}

// TestIsJTIRevoked_NonExistent verifies that checking a non-existent JTI
// returns false.
func TestIsJTIRevoked_NonExistent(t *testing.T) {
	if IsJTIRevoked("nonexistent-jti-12345") {
		t.Error("expected IsJTIRevoked to return false for non-existent JTI")
	}
}

// =============================================================================
// CleanupRevokedJTIs Tests
// =============================================================================

// TestCleanupRevokedJTIs_RemovesExpired adds a JTI with a past expiry time,
// runs CleanupRevokedJTIs, and verifies the JTI is removed from the set.
func TestCleanupRevokedJTIs_RemovesExpired(t *testing.T) {
	requiresDB(t)
	_, jti, err := GenerateToken("user-007", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	// Add with future expiry so IsJTIRevoked sees it
	RevokeJTI(jti, time.Now().Add(1*time.Hour))

	if !IsJTIRevoked(jti) {
		t.Fatal("JTI should be in revoked set after RevokeJTI")
	}

	// Directly update the DB to set expiry in the past
	_, err = db.DB.Exec(context.Background(),
		"UPDATE revoked_jtis SET expires_at = NOW() - INTERVAL '1 hour' WHERE jti = $1", jti)
	if err != nil {
		t.Fatalf("failed to expire JTI: %v", err)
	}

	CleanupRevokedJTIs()

	if IsJTIRevoked(jti) {
		t.Error("expected expired JTI to be removed after cleanup")
	}
}

// TestCleanupRevokedJTIs_KeepsValid adds a JTI with a future expiry time,
// runs CleanupRevokedJTIs, and verifies the JTI is still in the set.
func TestCleanupRevokedJTIs_KeepsValid(t *testing.T) {
	requiresDB(t)
	_, jti, err := GenerateToken("user-008", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	// Add with future expiry
	RevokeJTI(jti, time.Now().Add(30*24*time.Hour))

	if !IsJTIRevoked(jti) {
		t.Fatal("JTI should be in revoked set before cleanup")
	}

	CleanupRevokedJTIs()

	if !IsJTIRevoked(jti) {
		t.Error("expected valid (future expiry) JTI to remain after cleanup")
	}
}