package auth_test

import (
	"context"
	"errors"
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"code.nochebuena.dev/einherjar/auth/authmw"
	"code.nochebuena.dev/einherjar/auth/rbac"
	"code.nochebuena.dev/einherjar/contracts/security"
	"code.nochebuena.dev/einherjar/core/logz"
)

// ── Compile-time interface satisfaction ──────────────────────────────────────

var _ authmw.IdentityEnricher = (*mockEnricher)(nil)
var _ security.PermissionProvider = rbac.NewClaimsPermissionProvider("x", authmw.GetClaims)
var _ security.PermissionProvider = rbac.NewCachedPermissionProvider(rbac.NewClaimsPermissionProvider("x", authmw.GetClaims), &mockCache{}, time.Minute)
var _ security.PermissionProvider = rbac.NewChainPermissionProvider()
var _ rbac.Cache = (*mockCache)(nil)

// ── Structural: at most one exported TypeSpec per file ────────────────────────

func TestAtMostOneExportedTypePerFile(t *testing.T) {
	fset := token.NewFileSet()
	err := filepath.WalkDir(".", func(path string, d os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() && (d.Name() == ".git" || d.Name() == "vendor") {
			return filepath.SkipDir
		}
		if !strings.HasSuffix(path, ".go") {
			return nil
		}
		if strings.HasSuffix(path, "_test.go") {
			return nil
		}
		if filepath.Base(path) == "doc.go" {
			return nil
		}
		f, parseErr := parser.ParseFile(fset, path, nil, 0)
		if parseErr != nil {
			t.Errorf("%s: parse error: %v", path, parseErr)
			return nil
		}
		if count := countExportedTypes(f); count > 1 {
			t.Errorf("%s: has %d exported type declarations; want at most 1", path, count)
		}
		return nil
	})
	if err != nil {
		t.Fatalf("walk error: %v", err)
	}
}

func countExportedTypes(f *ast.File) int {
	count := 0
	for _, decl := range f.Decls {
		gd, ok := decl.(*ast.GenDecl)
		if !ok {
			continue
		}
		for _, spec := range gd.Specs {
			ts, ok := spec.(*ast.TypeSpec)
			if ok && ts.Name.IsExported() {
				count++
			}
		}
	}
	return count
}

// ── authmw: SetTokenData ──────────────────────────────────────────────────────

func TestSetTokenData(t *testing.T) {
	ctx := context.Background()
	claims := map[string]any{"perms": map[string]any{"orders": int64(7)}}
	ctx = authmw.SetTokenData(ctx, "uid-1", claims)

	got := authmw.GetClaims(ctx)
	if got == nil {
		t.Fatal("GetClaims returned nil after SetTokenData")
	}
	if _, ok := got["perms"]; !ok {
		t.Error("claims key 'perms' missing")
	}
}

// ── authmw: EnrichmentMiddleware ──────────────────────────────────────────────

func TestEnrichmentMiddlewareSuccess(t *testing.T) {
	logger := logz.New(logz.Config{})
	enricher := &mockEnricher{identity: security.NewIdentity("uid-1", "Alice", "alice@example.com")}

	h := authmw.EnrichmentMiddleware(logger, enricher)(okHandler())

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r = r.WithContext(authmw.SetTokenData(r.Context(), "uid-1", nil))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusOK {
		t.Errorf("status: got %d, want 200", w.Code)
	}
	if !enricher.called {
		t.Error("enricher was not called")
	}
}

func TestEnrichmentMiddlewareMissingUID(t *testing.T) {
	logger := logz.New(logz.Config{})
	enricher := &mockEnricher{}

	h := authmw.EnrichmentMiddleware(logger, enricher)(okHandler())

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusUnauthorized {
		t.Errorf("status: got %d, want 401", w.Code)
	}
	if enricher.called {
		t.Error("enricher should not be called when uid is missing")
	}
}

func TestEnrichmentMiddlewareEnricherError(t *testing.T) {
	logger := logz.New(logz.Config{})
	enricher := &mockEnricher{err: errors.New("db down")}

	h := authmw.EnrichmentMiddleware(logger, enricher)(okHandler())

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r = r.WithContext(authmw.SetTokenData(r.Context(), "uid-1", nil))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusInternalServerError {
		t.Errorf("status: got %d, want 500", w.Code)
	}
}

func TestEnrichmentMiddlewareTenantHeader(t *testing.T) {
	logger := logz.New(logz.Config{})
	enricher := &mockEnricher{identity: security.NewIdentity("uid-1", "Alice", "alice@example.com")}

	h := authmw.EnrichmentMiddleware(logger, enricher, authmw.WithTenantHeader("X-Tenant-ID"))(
		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			id, ok := security.FromContext(r.Context())
			if !ok {
				t.Error("identity not in context")
			}
			if id.TenantID != "tenant-abc" {
				t.Errorf("TenantID: got %q, want %q", id.TenantID, "tenant-abc")
			}
			w.WriteHeader(http.StatusOK)
		}),
	)

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r.Header.Set("X-Tenant-ID", "tenant-abc")
	r = r.WithContext(authmw.SetTokenData(r.Context(), "uid-1", nil))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusOK {
		t.Errorf("status: got %d, want 200", w.Code)
	}
}

// TestEnrichmentMiddlewareBagEnricher verifies that WithBagEnricher attaches a
// custom attribute to the SecurityBag stored in context.
func TestEnrichmentMiddlewareBagEnricher(t *testing.T) {
	logger := logz.New(logz.Config{})
	enricher := &mockEnricher{identity: security.NewIdentity("uid-1", "Alice", "alice@example.com")}

	hwEnricher := authmw.BagEnricher(func(bag security.SecurityBag, r *http.Request) security.SecurityBag {
		return bag.With("hardware_id", r.Header.Get("X-Hardware-ID"))
	})

	h := authmw.EnrichmentMiddleware(logger, enricher, authmw.WithBagEnricher(hwEnricher))(
		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			bag, ok := security.BagFromContext(r.Context())
			if !ok {
				t.Error("bag not in context")
				w.WriteHeader(http.StatusInternalServerError)
				return
			}
			v, ok := bag.Get("hardware_id")
			if !ok {
				t.Error("hardware_id not in bag")
			} else if v != "hw-abc" {
				t.Errorf("hardware_id: got %v, want hw-abc", v)
			}
			w.WriteHeader(http.StatusOK)
		}),
	)

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r.Header.Set("X-Hardware-ID", "hw-abc")
	r = r.WithContext(authmw.SetTokenData(r.Context(), "uid-1", nil))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusOK {
		t.Errorf("status: got %d, want 200", w.Code)
	}
}

// TestEnrichmentMiddlewareBagInContext verifies that security.BagFromContext works
// after enrichment, and that the bag carries the enriched Identity.
func TestEnrichmentMiddlewareBagInContext(t *testing.T) {
	logger := logz.New(logz.Config{})
	id := security.NewIdentity("uid-1", "Alice", "alice@example.com")
	enricher := &mockEnricher{identity: id}

	h := authmw.EnrichmentMiddleware(logger, enricher)(
		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			bag, ok := security.BagFromContext(r.Context())
			if !ok {
				t.Error("BagFromContext: want ok=true, got false")
				w.WriteHeader(http.StatusInternalServerError)
				return
			}
			if bag.Identity() != id {
				t.Errorf("bag identity: got %+v, want %+v", bag.Identity(), id)
			}
			w.WriteHeader(http.StatusOK)
		}),
	)

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	r = r.WithContext(authmw.SetTokenData(r.Context(), "uid-1", nil))
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusOK {
		t.Errorf("status: got %d, want 200", w.Code)
	}
}

// ── authmw: AuthzMiddleware ───────────────────────────────────────────────────

func TestAuthzMiddlewareAllowed(t *testing.T) {
	logger := logz.New(logz.Config{})
	const ReadOrders = security.Permission(0)
	provider := &mockProvider{mask: security.PermissionMask(0).Grant(ReadOrders)}

	h := authmw.AuthzMiddleware(logger, provider, "orders", ReadOrders)(okHandler())

	id := security.NewIdentity("uid-1", "Alice", "alice@example.com")
	ctx := security.SetInContext(context.Background(), id)
	r := httptest.NewRequest(http.MethodGet, "/", nil).WithContext(ctx)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusOK {
		t.Errorf("status: got %d, want 200", w.Code)
	}
}

func TestAuthzMiddlewareMissingIdentity(t *testing.T) {
	logger := logz.New(logz.Config{})
	provider := &mockProvider{}

	h := authmw.AuthzMiddleware(logger, provider, "orders", 0)(okHandler())

	r := httptest.NewRequest(http.MethodGet, "/", nil)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusUnauthorized {
		t.Errorf("status: got %d, want 401", w.Code)
	}
}

func TestAuthzMiddlewarePermissionDenied(t *testing.T) {
	logger := logz.New(logz.Config{})
	provider := &mockProvider{mask: 0} // no permissions

	h := authmw.AuthzMiddleware(logger, provider, "orders", security.Permission(0))(okHandler())

	id := security.NewIdentity("uid-1", "Alice", "alice@example.com")
	ctx := security.SetInContext(context.Background(), id)
	r := httptest.NewRequest(http.MethodGet, "/", nil).WithContext(ctx)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusForbidden {
		t.Errorf("status: got %d, want 403", w.Code)
	}
}

func TestAuthzMiddlewareProviderError(t *testing.T) {
	logger := logz.New(logz.Config{})
	provider := &mockProvider{err: errors.New("db error")}

	h := authmw.AuthzMiddleware(logger, provider, "orders", security.Permission(0))(okHandler())

	id := security.NewIdentity("uid-1", "Alice", "alice@example.com")
	ctx := security.SetInContext(context.Background(), id)
	r := httptest.NewRequest(http.MethodGet, "/", nil).WithContext(ctx)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, r)

	if w.Code != http.StatusForbidden {
		t.Errorf("status: got %d, want 403 (fail-closed on provider error)", w.Code)
	}
}

// ── rbac: ClaimsPermissionProvider ───────────────────────────────────────────

func TestClaimsProviderHit(t *testing.T) {
	p := rbac.NewClaimsPermissionProvider("perms", authmw.GetClaims)
	claims := map[string]any{
		"perms": map[string]any{"orders": int64(7)},
	}
	ctx := authmw.SetTokenData(context.Background(), "uid-1", claims)

	mask, err := p.ResolveMask(ctx, "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 7 {
		t.Errorf("mask: got %d, want 7", mask)
	}
}

func TestClaimsProviderWildcard(t *testing.T) {
	p := rbac.NewClaimsPermissionProvider("perms", authmw.GetClaims)
	claims := map[string]any{
		"perms": map[string]any{"*": int64(15)},
	}
	ctx := authmw.SetTokenData(context.Background(), "uid-1", claims)

	mask, err := p.ResolveMask(ctx, "uid-1", "products")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 15 {
		t.Errorf("mask: got %d, want 15 (wildcard)", mask)
	}
}

func TestClaimsProviderMissing(t *testing.T) {
	p := rbac.NewClaimsPermissionProvider("perms", authmw.GetClaims)
	ctx := context.Background() // no claims set

	mask, err := p.ResolveMask(ctx, "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 0 {
		t.Errorf("mask: got %d, want 0", mask)
	}
}

func TestClaimsProviderFloat64(t *testing.T) {
	p := rbac.NewClaimsPermissionProvider("perms", authmw.GetClaims)
	claims := map[string]any{
		"perms": map[string]any{"orders": float64(3)},
	}
	ctx := authmw.SetTokenData(context.Background(), "uid-1", claims)

	mask, err := p.ResolveMask(ctx, "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 3 {
		t.Errorf("mask: got %d, want 3 (float64 cast)", mask)
	}
}

// ── rbac: CachedPermissionProvider ───────────────────────────────────────────

func TestCachedProviderHit(t *testing.T) {
	inner := &mockProvider{mask: 7}
	cache := &mockCache{data: map[string]int64{"rbac:uid-1:orders": 99}}
	p := rbac.NewCachedPermissionProvider(inner, cache, time.Minute)

	mask, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 99 {
		t.Errorf("mask: got %d, want 99 (from cache)", mask)
	}
	if inner.calls != 0 {
		t.Error("inner provider should not be called on cache hit")
	}
}

func TestCachedProviderMiss(t *testing.T) {
	inner := &mockProvider{mask: 7}
	cache := &mockCache{data: map[string]int64{}}
	p := rbac.NewCachedPermissionProvider(inner, cache, time.Minute)

	mask, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 7 {
		t.Errorf("mask: got %d, want 7 (from inner)", mask)
	}
	if inner.calls != 1 {
		t.Error("inner provider should be called on cache miss")
	}
	if cache.data["rbac:uid-1:orders"] != 7 {
		t.Error("result should be stored in cache after miss")
	}
}

func TestCachedProviderCacheError(t *testing.T) {
	inner := &mockProvider{mask: 5}
	cache := &mockCache{getErr: errors.New("valkey down")}
	p := rbac.NewCachedPermissionProvider(inner, cache, time.Minute)

	mask, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 5 {
		t.Errorf("mask: got %d, want 5 (fallthrough on cache error)", mask)
	}
}

func TestCachedProviderTenantKey(t *testing.T) {
	inner := &mockProvider{mask: 3}
	cache := &mockCache{data: map[string]int64{}}
	p := rbac.NewCachedPermissionProvider(inner, cache, time.Minute)

	id := security.NewIdentity("uid-1", "Alice", "alice@example.com").WithTenant("tenant-abc")
	ctx := security.SetInContext(context.Background(), id)

	_, err := p.ResolveMask(ctx, "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	const wantKey = "rbac:tenant-abc:uid-1:orders"
	if _, ok := cache.data[wantKey]; !ok {
		t.Errorf("expected cache key %q; got keys: %v", wantKey, cache.keys())
	}
	if _, ok := cache.data["rbac:uid-1:orders"]; ok {
		t.Error("tenant-scoped key must not omit tenantID")
	}
}

// TestWithCacheKey verifies that a custom CachedOpt key function is used instead
// of the default, enabling bag attributes (e.g. hardware ID) to be part of the key.
func TestWithCacheKey(t *testing.T) {
	inner := &mockProvider{mask: 7}
	cache := &mockCache{data: map[string]int64{}}
	p := rbac.NewCachedPermissionProvider(inner, cache, time.Minute,
		rbac.WithCacheKey(func(bag security.SecurityBag, uid, resource string) string {
			hwID, _ := bag.Get("hardware_id")
			return fmt.Sprintf("custom:%s:%v:%s", uid, hwID, resource)
		}),
	)

	bag := security.NewSecurityBag(security.NewIdentity("uid-1", "Alice", "a@b.com")).
		With("hardware_id", "hw-xyz")
	ctx := security.SetBagInContext(context.Background(), bag)

	_, err := p.ResolveMask(ctx, "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	const wantKey = "custom:uid-1:hw-xyz:orders"
	if _, ok := cache.data[wantKey]; !ok {
		t.Errorf("expected custom cache key %q; got keys: %v", wantKey, cache.keys())
	}
}

// ── rbac: ChainPermissionProvider ────────────────────────────────────────────

func TestChainProviderFirstNonZero(t *testing.T) {
	first := &mockProvider{mask: 7}
	second := &mockProvider{mask: 99}
	p := rbac.NewChainPermissionProvider(first, second)

	mask, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 7 {
		t.Errorf("mask: got %d, want 7 (first non-zero)", mask)
	}
	if second.calls != 0 {
		t.Error("second provider should not be called when first returns non-zero")
	}
}

func TestChainProviderFallthrough(t *testing.T) {
	first := &mockProvider{mask: 0}
	second := &mockProvider{mask: 5}
	p := rbac.NewChainPermissionProvider(first, second)

	mask, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if mask != 5 {
		t.Errorf("mask: got %d, want 5 (fallthrough to second)", mask)
	}
}

func TestChainProviderError(t *testing.T) {
	first := &mockProvider{err: errors.New("provider down")}
	second := &mockProvider{mask: 99}
	p := rbac.NewChainPermissionProvider(first, second)

	_, err := p.ResolveMask(context.Background(), "uid-1", "orders")
	if err == nil {
		t.Fatal("expected error, got nil")
	}
	if second.calls != 0 {
		t.Error("second provider should not be called after error in first")
	}
}

// ── helpers ───────────────────────────────────────────────────────────────────

func okHandler() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	})
}

type mockEnricher struct {
	identity security.Identity
	err      error
	called   bool
}

func (m *mockEnricher) Enrich(_ context.Context, _ string, _ map[string]any) (security.Identity, error) {
	m.called = true
	return m.identity, m.err
}

type mockProvider struct {
	mask  security.PermissionMask
	err   error
	calls int
}

func (m *mockProvider) ResolveMask(_ context.Context, _, _ string) (security.PermissionMask, error) {
	m.calls++
	return m.mask, m.err
}

type mockCache struct {
	data   map[string]int64
	getErr error
}

func (m *mockCache) Get(_ context.Context, key string) (int64, bool, error) {
	if m.getErr != nil {
		return 0, false, m.getErr
	}
	v, ok := m.data[key]
	return v, ok, nil
}

func (m *mockCache) Set(_ context.Context, key string, value int64, _ time.Duration) error {
	if m.data == nil {
		m.data = map[string]int64{}
	}
	m.data[key] = value
	return nil
}

func (m *mockCache) keys() []string {
	keys := make([]string, 0, len(m.data))
	for k := range m.data {
		keys = append(keys, k)
	}
	return keys
}