//go: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/clock"
	"crussell/db"
	"crussell/testutils/fixtures"
	"crussell/testutils/testtx"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// =============================================================================
// 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) {
	ctx, _ := testtx.SetupTestTx(t)
	token, jti, err := GenerateToken("user-003", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

	userID, role, returnedJTI, err := VerifyToken(token, ctx)
	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) {
	ctx, _ := testtx.SetupTestTx(t)
	token, jti, err := GenerateToken("user-004", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

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

	_, _, _, err = VerifyToken(token, ctx)
	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":     clock.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)
	}
}

// TestIsJTIRevoked_QueryError verifies that IsJTIRevoked returns false when
// the context is cancelled (causing the QueryRow to fail).
func TestIsJTIRevoked_QueryError(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	if IsJTIRevoked(ctx, "test-jti") {
		t.Error("expected false on cancelled context query error")
	}
}

// =============================================================================
// 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) {
	ctx, _ := testtx.SetupTestTx(t)
	_, jti, err := GenerateToken("user-006", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

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

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

	if !IsJTIRevoked(ctx, 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) {
	ctx, _ := testtx.SetupTestTx(t)
	if IsJTIRevoked(ctx, "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) {
	ctx, tx := testtx.SetupTestTx(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(ctx, jti, clock.Now().Add(1*time.Hour))

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

	// Directly update the DB to set expiry in the past
	_, err = tx.Exec(ctx,
		"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(ctx)

	if IsJTIRevoked(ctx, 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) {
	ctx, _ := testtx.SetupTestTx(t)
	_, jti, err := GenerateToken("user-008", "verified_email")
	if err != nil {
		t.Fatalf("GenerateToken() failed: %v", err)
	}

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

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

	CleanupRevokedJTIs(ctx)

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

// =============================================================================
// generateRefreshTokenString Tests
// =============================================================================

// TestGenerateRefreshTokenString_Format verifies that generateRefreshTokenString
// returns a 64-character hex string.
func TestGenerateRefreshTokenString_Format(t *testing.T) {
	token, err := generateRefreshTokenString()
	if err != nil {
		t.Fatalf("generateRefreshTokenString() failed: %v", err)
	}
	if len(token) != 64 {
		t.Errorf("expected 64-character hex string, got length %d: %s", len(token), token)
	}
	// Verify all characters are valid lowercase hex
	for _, c := range token {
		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
			t.Errorf("non-hex character %c in token %s", c, token)
			break
		}
	}
}

// TestGenerateRefreshTokenString_Unique generates 100 refresh token strings
// and verifies all are unique.
func TestGenerateRefreshTokenString_Unique(t *testing.T) {
	seen := make(map[string]bool)
	for i := 0; i < 100; i++ {
		token, err := generateRefreshTokenString()
		if err != nil {
			t.Fatalf("generateRefreshTokenString() failed at iteration %d: %v", i, err)
		}
		if seen[token] {
			t.Errorf("duplicate refresh token at iteration %d: %s", i, token)
		}
		seen[token] = true
	}
	if len(seen) != 100 {
		t.Errorf("expected 100 unique tokens, got %d", len(seen))
	}
}

// =============================================================================
// GenerateRefreshToken Tests
// =============================================================================

// TestGenerateRefreshToken_Success calls GenerateRefreshToken and verifies a
// row was inserted in the refresh_tokens table with the correct user_id and role.
func TestGenerateRefreshToken_Success(t *testing.T) {
	ctx, tx := testtx.SetupTestTx(t)

	userID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create test user: %v", err)
	}

	token, err := GenerateRefreshToken(ctx, userID, "verified_email")
	if err != nil {
		t.Fatalf("GenerateRefreshToken() failed: %v", err)
	}
	if token == "" {
		t.Error("expected non-empty token")
	}

	// Verify row was inserted in refresh_tokens
	var dbUserID string
	var dbRole string
	err = tx.QueryRow(ctx,
		`SELECT user_id, role FROM refresh_tokens WHERE token_hash = encode(sha256($1::bytea), 'hex')`,
		token).Scan(&dbUserID, &dbRole)
	if err != nil {
		t.Fatalf("failed to query refresh_tokens: %v", err)
	}
	if dbUserID != userID {
		t.Errorf("expected user_id %q, got %q", userID, dbUserID)
	}
	if dbRole != "verified_email" {
		t.Errorf("expected role 'verified_email', got %q", dbRole)
	}
}

// =============================================================================
// VerifyRefreshToken Tests
// =============================================================================

// TestVerifyRefreshToken_Success generates a refresh token, verifies it, and
// asserts the returned userID and role match. Then confirms the token was
// consumed (second call fails with "invalid or expired").
func TestVerifyRefreshToken_Success(t *testing.T) {
	ctx, tx := testtx.SetupTestTx(t)

	userID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create test user: %v", err)
	}

	token, err := GenerateRefreshToken(ctx, userID, "verified_email")
	if err != nil {
		t.Fatalf("GenerateRefreshToken() failed: %v", err)
	}

	// First verify should succeed
	retUserID, retRole, err := VerifyRefreshToken(ctx, token)
	if err != nil {
		t.Fatalf("VerifyRefreshToken() failed: %v", err)
	}
	if retUserID != userID {
		t.Errorf("expected user_id %q, got %q", userID, retUserID)
	}
	if retRole != "verified_email" {
		t.Errorf("expected role 'verified_email', got %q", retRole)
	}

	// Second verify with same token must fail (rotation — token consumed)
	_, _, err = VerifyRefreshToken(ctx, token)
	if err == nil {
		t.Fatal("expected error for consumed token, got nil")
	}
	if !strings.Contains(err.Error(), "invalid or expired") {
		t.Errorf("expected 'invalid or expired' error, got: %v", err)
	}
}

// TestVerifyRefreshToken_Rotation verifies the token rotation mechanism:
// first call succeeds, second call with the same token fails.
func TestVerifyRefreshToken_Rotation(t *testing.T) {
	ctx, tx := testtx.SetupTestTx(t)

	userID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create test user: %v", err)
	}

	token, err := GenerateRefreshToken(ctx, userID, "verified_email")
	if err != nil {
		t.Fatalf("GenerateRefreshToken() failed: %v", err)
	}

	// First call should succeed
	_, _, err = VerifyRefreshToken(ctx, token)
	if err != nil {
		t.Fatalf("first verification should succeed, got: %v", err)
	}

	// Second call with the same token must fail
	_, _, err = VerifyRefreshToken(ctx, token)
	if err == nil {
		t.Fatal("expected error for rotated token, got nil")
	}
	if !strings.Contains(err.Error(), "invalid or expired") {
		t.Errorf("expected 'invalid or expired' error, got: %v", err)
	}
}

// TestVerifyRefreshToken_InvalidToken calls VerifyRefreshToken with a fake
// token string and expects it to fail with "invalid or expired".
func TestVerifyRefreshToken_InvalidToken(t *testing.T) {
	ctx, _ := testtx.SetupTestTx(t)

	_, _, err := VerifyRefreshToken(ctx, "this-is-a-completely-fake-token-string")
	if err == nil {
		t.Fatal("expected error for invalid token, got nil")
	}
	if !strings.Contains(err.Error(), "invalid or expired") {
		t.Errorf("expected 'invalid or expired' error, got: %v", err)
	}
}

// TestVerifyToken_EmptyJTI creates a token with an empty "jti" claim and
// verifies that VerifyToken returns an error containing "invalid jti claim".
func TestVerifyToken_EmptyJTI(t *testing.T) {
	_, tokenStr, err := TokenAuth.Encode(map[string]any{
		"user_id": "user-test",
		"role":    "verified_email",
		"jti":     "",
		"exp":     clock.Now().Add(1 * time.Hour).Unix(),
	})
	require.NoError(t, err)
	_, _, _, err = VerifyToken(tokenStr, context.Background())
	require.Error(t, err)
	assert.Contains(t, err.Error(), "invalid jti claim")
}

// =============================================================================
// Nil db.Conn Tests
// =============================================================================

// TestRevokeJTI_NilConn verifies that RevokeJTI does not panic when db.Conn is nil.
func TestRevokeJTI_NilConn(t *testing.T) {
	savedConn := db.Conn
	db.Conn = nil
	t.Cleanup(func() { db.Conn = savedConn })

	// Should not panic when db.Conn is nil
	RevokeJTI(context.Background(), "test-jti", time.Now())
}

// TestIsJTIRevoked_NilConn verifies that IsJTIRevoked returns false when db.Conn is nil.
func TestIsJTIRevoked_NilConn(t *testing.T) {
	savedConn := db.Conn
	db.Conn = nil
	t.Cleanup(func() { db.Conn = savedConn })

	if IsJTIRevoked(context.Background(), "test-jti") {
		t.Error("expected IsJTIRevoked to return false when db.Conn is nil")
	}
}

// TestCleanupRevokedJTIs_NilConn verifies CleanupRevokedJTIs returns (0, nil) when db.Conn is nil.
func TestCleanupRevokedJTIs_NilConn(t *testing.T) {
	savedConn := db.Conn
	db.Conn = nil
	t.Cleanup(func() { db.Conn = savedConn })

	n, err := CleanupRevokedJTIs(context.Background())
	if err != nil {
		t.Errorf("expected no error, got: %v", err)
	}
	if n != 0 {
		t.Errorf("expected 0 rows, got %d", n)
	}
}

// Note: crypto error paths in generateJTI() and generateRefreshTokenString()
// are unreachable on Go 1.26+ because crypto/rand.Read() calls runtime.fatal()
// instead of returning an error (see https://go.dev/issue/66821). The error
// return exists for backward compatibility with older Go versions.

// =============================================================================
// VerifyToken Edge Case Tests
// =============================================================================

// TestVerifyToken_MissingUserID creates a token without user_id claim and verifies
// VerifyToken returns an error containing "invalid user_id claim".
func TestVerifyToken_MissingUserID(t *testing.T) {
	_, tokenString, err := TokenAuth.Encode(map[string]any{
		"role": "admin",
		"jti":  "test-jti-001",
		"exp":  clock.Now().Add(1 * time.Hour).Unix(),
	})
	if err != nil {
		t.Fatalf("failed to encode token: %v", err)
	}

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

// TestVerifyToken_WrongUserIDType creates a token with user_id as an integer (wrong type)
// and verifies VerifyToken returns an error containing "invalid user_id claim".
func TestVerifyToken_WrongUserIDType(t *testing.T) {
	_, tokenString, err := TokenAuth.Encode(map[string]any{
		"user_id": 12345,
		"role":    "admin",
		"jti":     "test-jti-002",
		"exp":     clock.Now().Add(1 * time.Hour).Unix(),
	})
	if err != nil {
		t.Fatalf("failed to encode token: %v", err)
	}

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

// TestVerifyToken_MissingRole creates a token without role claim and verifies
// VerifyToken returns an error containing "invalid role claim".
func TestVerifyToken_MissingRole(t *testing.T) {
	_, tokenString, err := TokenAuth.Encode(map[string]any{
		"user_id": "user-001",
		"jti":     "test-jti-003",
		"exp":     clock.Now().Add(1 * time.Hour).Unix(),
	})
	if err != nil {
		t.Fatalf("failed to encode token: %v", err)
	}

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

// TestVerifyToken_WrongRoleType creates a token with role as an integer (wrong type)
// and verifies VerifyToken returns an error containing "invalid role claim".
func TestVerifyToken_WrongRoleType(t *testing.T) {
	_, tokenString, err := TokenAuth.Encode(map[string]any{
		"user_id": "user-001",
		"role":    12345,
		"jti":     "test-jti-004",
		"exp":     clock.Now().Add(1 * time.Hour).Unix(),
	})
	if err != nil {
		t.Fatalf("failed to encode token: %v", err)
	}

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