package api

import (
	"context"
	"net/http"
	"sync"
	"testing"
	"time"

	"github.com/iliaivanov/spec-kit-remote/cmd/dev-pod-api/internal/model"
)

// mockUsageStore implements UsageStore for testing.
type mockUsageStore struct {
	mu          sync.Mutex
	starts      []usageEvent
	stops       []usageEvent
	usageResult *model.UsageSummary
	dailyResult []model.DailyUsage
}

type usageEvent struct {
	userID  string
	podName string
}

func newMockUsageStore() *mockUsageStore {
	return &mockUsageStore{
		usageResult: &model.UsageSummary{},
	}
}

func (m *mockUsageStore) RecordPodStart(_ context.Context, userID, podName string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.starts = append(m.starts, usageEvent{userID, podName})
	return nil
}

func (m *mockUsageStore) RecordPodStop(_ context.Context, userID, podName string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.stops = append(m.stops, usageEvent{userID, podName})
	return nil
}

func (m *mockUsageStore) RecordResourceSample(_ context.Context, _, _ string, _, _ float64) error {
	return nil
}

func (m *mockUsageStore) RecordAIRequest(_ context.Context, _ string) error {
	return nil
}

func (m *mockUsageStore) GetUsage(_ context.Context, _ string, _ int, _ time.Month, _ int) (*model.UsageSummary, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.usageResult, nil
}

func (m *mockUsageStore) GetDailyUsage(_ context.Context, _ string, _ int, _ time.Month) ([]model.DailyUsage, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.dailyResult, nil
}

// --- GET /api/v1/users/{user}/usage ---

func TestGetUserUsage_Success(t *testing.T) {
	kv, _, us, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)
	us.addUser(user)

	rr := doRequest(router, http.MethodGet, "/api/v1/users/alice/usage", "", "dpk_test")
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
	}

	var resp map[string]model.UsageSummary
	decodeJSON(t, rr, &resp)
	if _, ok := resp["current_month"]; !ok {
		t.Fatal("response should contain 'current_month' key")
	}
}

func TestGetUserUsage_AdminCanViewOther(t *testing.T) {
	kv, _, us, router := newPodTestRouter()
	admin := &model.User{ID: "admin-user", Quota: model.DefaultQuota()}
	alice := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_admin", admin, model.RoleAdmin)
	us.addUser(admin)
	us.addUser(alice)

	rr := doRequest(router, http.MethodGet, "/api/v1/users/alice/usage", "", "dpk_admin")
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
	}
}

func TestGetUserUsage_Forbidden(t *testing.T) {
	kv, _, _, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)

	rr := doRequest(router, http.MethodGet, "/api/v1/users/bob/usage", "", "dpk_test")
	if rr.Code != http.StatusForbidden {
		t.Fatalf("expected 403, got %d: %s", rr.Code, rr.Body.String())
	}
}

func TestGetUserUsage_NotFound(t *testing.T) {
	kv, _, _, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)
	// Don't add alice to user store

	rr := doRequest(router, http.MethodGet, "/api/v1/users/alice/usage", "", "dpk_test")
	if rr.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d: %s", rr.Code, rr.Body.String())
	}
}

// --- GET /api/v1/billing/summary ---

func TestBillingSummary_AdminSuccess(t *testing.T) {
	kv, _, us, router := newPodTestRouter()
	admin := &model.User{ID: "admin-user", Quota: model.DefaultQuota()}
	alice := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_admin", admin, model.RoleAdmin)
	us.addUser(admin)
	us.addUser(alice)

	rr := doRequest(router, http.MethodGet, "/api/v1/billing/summary", "", "dpk_admin")
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
	}

	var summaries []model.UserUsageSummary
	decodeJSON(t, rr, &summaries)
	if len(summaries) != 2 {
		t.Fatalf("expected 2 user summaries, got %d", len(summaries))
	}
}

func TestBillingSummary_Forbidden(t *testing.T) {
	kv, _, _, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)

	rr := doRequest(router, http.MethodGet, "/api/v1/billing/summary", "", "dpk_test")
	if rr.Code != http.StatusForbidden {
		t.Fatalf("expected 403, got %d: %s", rr.Code, rr.Body.String())
	}
}

// --- GET /api/v1/billing/{user}/history ---

func TestBillingHistory_Success(t *testing.T) {
	kv, _, us, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)
	us.addUser(user)

	rr := doRequest(router, http.MethodGet, "/api/v1/billing/alice/history", "", "dpk_test")
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
	}

	var daily []model.DailyUsage
	decodeJSON(t, rr, &daily)
	// Empty history returns empty array
	if daily == nil {
		t.Fatal("expected non-nil array")
	}
}

func TestBillingHistory_AdminCanView(t *testing.T) {
	kv, _, us, router := newPodTestRouter()
	admin := &model.User{ID: "admin-user", Quota: model.DefaultQuota()}
	alice := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_admin", admin, model.RoleAdmin)
	us.addUser(admin)
	us.addUser(alice)

	rr := doRequest(router, http.MethodGet, "/api/v1/billing/alice/history", "", "dpk_admin")
	if rr.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
	}
}

func TestBillingHistory_Forbidden(t *testing.T) {
	kv, _, _, router := newPodTestRouter()
	user := &model.User{ID: "alice", Quota: model.DefaultQuota()}
	kv.addKey("dpk_test", user, model.RoleUser)

	rr := doRequest(router, http.MethodGet, "/api/v1/billing/bob/history", "", "dpk_test")
	if rr.Code != http.StatusForbidden {
		t.Fatalf("expected 403, got %d: %s", rr.Code, rr.Body.String())
	}
}

// --- Auth integration ---

func TestBillingRoutes_NoAuth(t *testing.T) {
	_, _, _, router := newPodTestRouter()

	routes := []struct {
		method string
		path   string
	}{
		{http.MethodGet, "/api/v1/users/alice/usage"},
		{http.MethodGet, "/api/v1/billing/summary"},
		{http.MethodGet, "/api/v1/billing/alice/history"},
	}

	for _, rt := range routes {
		t.Run(rt.method+" "+rt.path, func(t *testing.T) {
			rr := doRequest(router, rt.method, rt.path, "", "")
			if rr.Code != http.StatusUnauthorized {
				t.Fatalf("expected 401, got %d", rr.Code)
			}
		})
	}
}