package deviceauth

import (
	"context"
	"crypto/rand"
	"crypto/sha256"
	"database/sql"
	"encoding/hex"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"

	"cmbuyer/admin/internal/migrations"
	"cmbuyer/admin/internal/storage/sqlite"
)

func TestIssueStoresOnlyRawTokenHashAndGenericJSONOmitsSecret(t *testing.T) {
	database, store := newCredentialStore(t)
	first, err := store.Issue(context.Background(), "采购工具一号")
	if err != nil {
		t.Fatalf("Issue first: %v", err)
	}
	second, err := store.Issue(context.Background(), "采购工具二号")
	if err != nil {
		t.Fatalf("Issue second: %v", err)
	}
	if first.DeviceID == second.DeviceID || first.Token == second.Token || !ValidDeviceID(first.DeviceID) || !validLowerHex(first.Token, tokenHexLength) {
		t.Fatalf("issued identifiers are not independent canonical values")
	}

	rawToken, err := hex.DecodeString(first.Token)
	if err != nil {
		t.Fatalf("decode issued token: %v", err)
	}
	wantHash := sha256.Sum256(rawToken)
	var storedHash []byte
	var storageType string
	if err := database.QueryRow(`SELECT token_sha256, typeof(token_sha256) FROM device_credentials WHERE device_id = ?`, first.DeviceID).Scan(&storedHash, &storageType); err != nil {
		t.Fatalf("read stored hash: %v", err)
	}
	if storageType != "blob" || len(storedHash) != sha256.Size || !equalBytes(storedHash, wantHash[:]) {
		t.Fatalf("stored hash type/length/value = %q/%d/%t", storageType, len(storedHash), equalBytes(storedHash, wantHash[:]))
	}
	var leakedCopies int
	if err := database.QueryRow(`SELECT COUNT(*) FROM device_credentials WHERE CAST(token_sha256 AS TEXT) IN (?, ?)`, first.Token, hex.EncodeToString(wantHash[:])).Scan(&leakedCopies); err != nil {
		t.Fatalf("search token copies: %v", err)
	}
	if leakedCopies != 0 {
		t.Fatal("database stored a plaintext or hex-encoded token/hash copy")
	}
	encoded, err := json.Marshal(first)
	if err != nil {
		t.Fatalf("marshal issued credential: %v", err)
	}
	if strings.Contains(string(encoded), first.Token) || strings.Contains(string(encoded), "token") {
		t.Fatalf("generic serialization disclosed token field: %s", encoded)
	}
}

func TestAuthenticateStrictHeaderMatrixAndBinding(t *testing.T) {
	_, store := newCredentialStore(t)
	first, err := store.Issue(context.Background(), "one")
	if err != nil {
		t.Fatalf("issue first: %v", err)
	}
	second, err := store.Issue(context.Background(), "two")
	if err != nil {
		t.Fatalf("issue second: %v", err)
	}
	authenticator := authenticatorForStore(t, store)

	for _, scheme := range []string{"Bearer", "bearer", "BEARER"} {
		request := credentialRequest(first.DeviceID, scheme+" "+first.Token)
		principal, err := authenticator.Authenticate(request)
		if err != nil || principal.ID != first.DeviceID {
			t.Fatalf("scheme %q Authenticate = (%q, %v)", scheme, principal.ID, err)
		}
	}

	unknownID := newRuntimeUUID(t)
	wrongToken := newRuntimeToken(t)
	tests := []struct {
		name   string
		mutate func(*http.Request)
	}{
		{"missing authorization", func(request *http.Request) { request.Header.Del(AuthorizationHeader) }},
		{"missing device", func(request *http.Request) { request.Header.Del(DeviceIDHeader) }},
		{"empty authorization", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "") }},
		{"empty device", func(request *http.Request) { request.Header.Set(DeviceIDHeader, "") }},
		{"duplicate authorization", func(request *http.Request) { request.Header.Add(AuthorizationHeader, "Bearer "+first.Token) }},
		{"duplicate device", func(request *http.Request) { request.Header.Add(DeviceIDHeader, first.DeviceID) }},
		{"combined authorization", func(request *http.Request) {
			request.Header.Set(AuthorizationHeader, "Bearer "+first.Token+", Bearer "+first.Token)
		}},
		{"combined device", func(request *http.Request) { request.Header.Set(DeviceIDHeader, first.DeviceID+", "+first.DeviceID) }},
		{"extra separator", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer  "+first.Token) }},
		{"tab separator", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer\t"+first.Token) }},
		{"uppercase token", func(request *http.Request) {
			request.Header.Set(AuthorizationHeader, "Bearer "+strings.ToUpper(first.Token))
		}},
		{"short token", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer "+first.Token[:62]) }},
		{"long token", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer "+first.Token+"00") }},
		{"non hex token", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer "+first.Token[:63]+"g") }},
		{"token separator", func(request *http.Request) {
			request.Header.Set(AuthorizationHeader, "Bearer "+first.Token[:32]+"-"+first.Token[33:])
		}},
		{"uppercase device", func(request *http.Request) { request.Header.Set(DeviceIDHeader, strings.ToUpper(first.DeviceID)) }},
		{"padded device", func(request *http.Request) { request.Header.Set(DeviceIDHeader, " "+first.DeviceID) }},
		{"wrong uuid version", func(request *http.Request) {
			request.Header.Set(DeviceIDHeader, first.DeviceID[:14]+"3"+first.DeviceID[15:])
		}},
		{"wrong uuid variant", func(request *http.Request) {
			request.Header.Set(DeviceIDHeader, first.DeviceID[:19]+"7"+first.DeviceID[20:])
		}},
		{"unknown device", func(request *http.Request) { request.Header.Set(DeviceIDHeader, unknownID) }},
		{"wrong token", func(request *http.Request) { request.Header.Set(AuthorizationHeader, "Bearer "+wrongToken) }},
		{"token device mismatch", func(request *http.Request) { request.Header.Set(DeviceIDHeader, second.DeviceID) }},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			request := credentialRequest(first.DeviceID, "Bearer "+first.Token)
			test.mutate(request)
			principal, err := authenticator.Authenticate(request)
			if !errors.Is(err, ErrUnauthenticated) || principal != (Principal{}) {
				t.Fatalf("Authenticate = (%#v, %v), want empty unauthenticated", principal, err)
			}
		})
	}
	if principal, err := authenticator.Authenticate(nil); !errors.Is(err, ErrUnauthenticated) || principal != (Principal{}) {
		t.Fatalf("Authenticate(nil) = (%#v, %v)", principal, err)
	}
}

func TestRevokeIsImmediateAndIdempotent(t *testing.T) {
	_, store := newCredentialStore(t)
	issued, err := store.Issue(context.Background(), "device")
	if err != nil {
		t.Fatalf("Issue: %v", err)
	}
	authenticator := authenticatorForStore(t, store)
	request := credentialRequest(issued.DeviceID, "Bearer "+issued.Token)
	if _, err := authenticator.Authenticate(request); err != nil {
		t.Fatalf("Authenticate before revoke: %v", err)
	}

	first, changed, err := store.Revoke(context.Background(), issued.DeviceID)
	if err != nil || !changed || first.Status != StatusRevoked || first.RevokedAt == nil {
		t.Fatalf("first Revoke = (%#v, %t, %v)", first, changed, err)
	}
	if principal, err := authenticator.Authenticate(request); !errors.Is(err, ErrUnauthenticated) || principal != (Principal{}) {
		t.Fatalf("Authenticate after committed revoke = (%#v, %v)", principal, err)
	}
	second, changed, err := store.Revoke(context.Background(), issued.DeviceID)
	if err != nil || changed || second.RevokedAt == nil || !second.RevokedAt.Equal(*first.RevokedAt) {
		t.Fatalf("second Revoke = (%#v, %t, %v)", second, changed, err)
	}
	listed, err := store.List(context.Background())
	if err != nil || len(listed) != 1 || listed[0].Status != StatusRevoked {
		t.Fatalf("List = (%#v, %v)", listed, err)
	}
}

func TestConcurrentAuthenticationAndRevocation(t *testing.T) {
	_, store := newCredentialStore(t)
	issued, err := store.Issue(context.Background(), "concurrent")
	if err != nil {
		t.Fatalf("Issue: %v", err)
	}
	authenticator := authenticatorForStore(t, store)
	request := func() *http.Request { return credentialRequest(issued.DeviceID, "Bearer "+issued.Token) }
	start := make(chan struct{})
	results := make(chan error, 16)
	var wait sync.WaitGroup
	for index := 0; index < 16; index++ {
		wait.Add(1)
		go func() {
			defer wait.Done()
			<-start
			_, err := authenticator.Authenticate(request())
			results <- err
		}()
	}
	close(start)
	if _, _, err := store.Revoke(context.Background(), issued.DeviceID); err != nil {
		t.Fatalf("Revoke: %v", err)
	}
	wait.Wait()
	close(results)
	for err := range results {
		if err != nil && !errors.Is(err, ErrUnauthenticated) {
			t.Fatalf("concurrent Authenticate error = %v", err)
		}
	}
	for index := 0; index < 16; index++ {
		if _, err := authenticator.Authenticate(request()); !errors.Is(err, ErrUnauthenticated) {
			t.Fatalf("post-commit Authenticate %d error = %v", index, err)
		}
	}
}

func TestAuthenticationDatabaseFaultAndCorruptionAreUnavailable(t *testing.T) {
	database, store := newCredentialStore(t)
	issued, err := store.Issue(context.Background(), "device")
	if err != nil {
		t.Fatalf("Issue: %v", err)
	}
	authenticator := authenticatorForStore(t, store)
	if err := database.Close(); err != nil {
		t.Fatalf("close database: %v", err)
	}
	if _, err := authenticator.Authenticate(credentialRequest(issued.DeviceID, "Bearer "+issued.Token)); !errors.Is(err, ErrUnavailable) {
		t.Fatalf("closed database Authenticate error = %v", err)
	}

	corruptDB, err := sqlite.Open(filepath.Join(t.TempDir(), "corrupt.db"))
	if err != nil {
		t.Fatalf("open corrupt database: %v", err)
	}
	t.Cleanup(func() { _ = corruptDB.Close() })
	if _, err := corruptDB.Exec(`CREATE TABLE device_credentials (device_id TEXT PRIMARY KEY, token_sha256 BLOB, status TEXT, revoked_at TEXT)`); err != nil {
		t.Fatalf("create corrupt table: %v", err)
	}
	corruptAuthenticator, err := NewSQLiteAuthenticator(corruptDB)
	if err != nil {
		t.Fatalf("new corrupt authenticator: %v", err)
	}
	tests := []struct {
		name      string
		hashValue func([sha256.Size]byte) any
		status    string
		revokedAt any
	}{
		{name: "null hash", hashValue: func([sha256.Size]byte) any { return nil }, status: StatusActive},
		{name: "matching text hash", hashValue: func(hash [sha256.Size]byte) any { return string(hash[:]) }, status: StatusActive},
		{name: "unknown status", hashValue: func(hash [sha256.Size]byte) any { return hash[:] }, status: "BROKEN"},
		{name: "active with revoked time", hashValue: func(hash [sha256.Size]byte) any { return hash[:] }, status: StatusActive, revokedAt: "2026-08-04T00:00:00Z"},
		{name: "revoked without time", hashValue: func(hash [sha256.Size]byte) any { return hash[:] }, status: StatusRevoked},
		{name: "revoked with invalid time", hashValue: func(hash [sha256.Size]byte) any { return hash[:] }, status: StatusRevoked, revokedAt: "not-a-time"},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			rawToken, token := newRuntimeTokenPair(t)
			hash := sha256.Sum256(rawToken)
			deviceID := newRuntimeUUID(t)
			if _, err := corruptDB.Exec(`INSERT INTO device_credentials VALUES (?, ?, ?, ?)`, deviceID, test.hashValue(hash), test.status, test.revokedAt); err != nil {
				t.Fatalf("insert corrupt row: %v", err)
			}
			principal, err := corruptAuthenticator.Authenticate(credentialRequest(deviceID, "Bearer "+token))
			if !errors.Is(err, ErrUnavailable) || principal != (Principal{}) {
				t.Fatalf("corrupt Authenticate = (%#v, %v), want unavailable", principal, err)
			}
		})
	}
}

func TestCredentialAuthenticationSurvivesDatabaseReopen(t *testing.T) {
	databaseSource := filepath.Join(t.TempDir(), "reopen.db")
	database, err := sqlite.Open(databaseSource)
	if err != nil {
		t.Fatalf("open database: %v", err)
	}
	if err := migrations.Up(context.Background(), database, deviceMigrationDirectory(t)); err != nil {
		_ = database.Close()
		t.Fatalf("migrate database: %v", err)
	}
	store, err := NewCredentialStore(database)
	if err != nil {
		_ = database.Close()
		t.Fatalf("new store: %v", err)
	}
	issued, err := store.Issue(context.Background(), "reopen")
	if err != nil {
		_ = database.Close()
		t.Fatalf("issue: %v", err)
	}
	if err := database.Close(); err != nil {
		t.Fatalf("close database: %v", err)
	}

	reopened, err := sqlite.Open(databaseSource)
	if err != nil {
		t.Fatalf("reopen database: %v", err)
	}
	defer reopened.Close()
	authenticator, err := NewSQLiteAuthenticator(reopened)
	if err != nil {
		t.Fatalf("new reopened authenticator: %v", err)
	}
	principal, err := authenticator.Authenticate(credentialRequest(issued.DeviceID, "Bearer "+issued.Token))
	if err != nil || principal.ID != issued.DeviceID {
		t.Fatalf("Authenticate after reopen = (%#v, %v)", principal, err)
	}
}

func TestCredentialInputAndMigrationAreRequired(t *testing.T) {
	database, err := sqlite.Open(filepath.Join(t.TempDir(), "unmigrated.db"))
	if err != nil {
		t.Fatalf("open database: %v", err)
	}
	t.Cleanup(func() { _ = database.Close() })
	if _, err := NewCredentialStore(database); err == nil {
		t.Fatal("NewCredentialStore accepted an unmigrated database")
	}
	if _, err := NewSQLiteAuthenticator(database); err == nil {
		t.Fatal("NewSQLiteAuthenticator accepted an unmigrated database")
	}

	_, store := newCredentialStore(t)
	for _, name := range []string{"", " leading", "trailing ", "line\nbreak", strings.Repeat("名", 129)} {
		if _, err := store.Issue(context.Background(), name); !errors.Is(err, ErrInvalidCredential) {
			t.Fatalf("Issue(%q) error = %v", name, err)
		}
	}
	if _, _, err := store.Revoke(context.Background(), "not-a-uuid"); !errors.Is(err, ErrInvalidCredential) {
		t.Fatalf("Revoke invalid id error = %v", err)
	}
	if _, _, err := store.Revoke(context.Background(), newRuntimeUUID(t)); !errors.Is(err, ErrCredentialNotFound) {
		t.Fatalf("Revoke unknown id error = %v", err)
	}
}

func newCredentialStore(t *testing.T) (*sql.DB, *CredentialStore) {
	t.Helper()
	databaseSource := filepath.Join(t.TempDir(), "device-auth.db") + "?_busy_timeout=5000&_journal_mode=WAL"
	database, err := sqlite.Open(databaseSource)
	if err != nil {
		t.Fatalf("open database: %v", err)
	}
	t.Cleanup(func() { _ = database.Close() })
	if err := migrations.Up(context.Background(), database, deviceMigrationDirectory(t)); err != nil {
		t.Fatalf("migrate database: %v", err)
	}
	store, err := NewCredentialStore(database)
	if err != nil {
		t.Fatalf("NewCredentialStore: %v", err)
	}
	store.now = func() time.Time { return time.Date(2026, 8, 4, 12, 0, 0, 123, time.UTC) }
	return database, store
}

func authenticatorForStore(t *testing.T, store *CredentialStore) *SQLiteAuthenticator {
	t.Helper()
	authenticator, err := NewSQLiteAuthenticator(store.database)
	if err != nil {
		t.Fatalf("NewSQLiteAuthenticator: %v", err)
	}
	return authenticator
}

func credentialRequest(deviceID, authorization string) *http.Request {
	request := httptest.NewRequest(http.MethodPost, "/api/v1/tasks/id/evidence", nil)
	request.Header.Set(DeviceIDHeader, deviceID)
	request.Header.Set(AuthorizationHeader, authorization)
	return request
}

func newRuntimeToken(t *testing.T) string {
	t.Helper()
	_, token := newRuntimeTokenPair(t)
	return token
}

func newRuntimeTokenPair(t *testing.T) ([]byte, string) {
	t.Helper()
	raw := make([]byte, 32)
	if _, err := rand.Read(raw); err != nil {
		t.Fatalf("generate runtime token: %v", err)
	}
	return raw, hex.EncodeToString(raw)
}

func newRuntimeUUID(t *testing.T) string {
	t.Helper()
	raw := make([]byte, 16)
	if _, err := rand.Read(raw); err != nil {
		t.Fatalf("generate runtime UUID: %v", err)
	}
	return formatUUIDv4(raw)
}

func equalBytes(left, right []byte) bool {
	if len(left) != len(right) {
		return false
	}
	for index := range left {
		if left[index] != right[index] {
			return false
		}
	}
	return true
}

func deviceMigrationDirectory(t *testing.T) string {
	t.Helper()
	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("locate migrations")
	}
	return filepath.Join(filepath.Dir(file), "..", "..", "migrations")
}