package api

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

	"cpa-usage-keeper/internal/cpa"
	"cpa-usage-keeper/internal/redact"
	"cpa-usage-keeper/internal/service"
)

type usageAnalysisStub struct {
	analysis      *service.UsageAnalysisSnapshot
	err           error
	lastFilter    service.UsageFilter
	analysisCalls int
}

func (s *usageAnalysisStub) GetUsageWithFilter(context.Context, service.UsageFilter) (*cpa.StatisticsSnapshot, error) {
	return nil, nil
}

func (s *usageAnalysisStub) GetUsageOverview(context.Context, service.UsageFilter) (*service.UsageOverviewSnapshot, error) {
	return nil, nil
}

func (s *usageAnalysisStub) ListUsageEvents(context.Context, service.UsageFilter) (*service.UsageEventsPage, error) {
	return nil, nil
}

func (s *usageAnalysisStub) ListUsageEventFilterOptions(context.Context, service.UsageFilter) (*service.UsageEventFilterOptions, error) {
	return nil, nil
}

func (s *usageAnalysisStub) ListUsageCredentialStats(context.Context, service.UsageFilter) ([]service.UsageCredentialStat, error) {
	return nil, nil
}

func (s *usageAnalysisStub) GetUsageAnalysis(_ context.Context, filter service.UsageFilter) (*service.UsageAnalysisSnapshot, error) {
	s.lastFilter = filter
	s.analysisCalls++
	return s.analysis, s.err
}

func TestUsageAnalysisReturnsAggregatedRows(t *testing.T) {
	provider := &usageAnalysisStub{analysis: &service.UsageAnalysisSnapshot{
		APIs: []service.UsageAnalysisAPIStat{{
			APIKey:        "provider-a",
			DisplayName:   "provider-a",
			TotalRequests: 2,
			SuccessCount:  1,
			FailureCount:  1,
			TotalTokens:   42,
			Models: []service.UsageAnalysisModelStat{{
				Model:              "claude-sonnet",
				TotalRequests:      2,
				SuccessCount:       1,
				FailureCount:       1,
				InputTokens:        30,
				OutputTokens:       9,
				ReasoningTokens:    2,
				CachedTokens:       1,
				TotalTokens:        42,
				TotalLatencyMS:     350,
				LatencySampleCount: 2,
			}},
		}},
		Models: []service.UsageAnalysisModelStat{{
			Model:              "claude-sonnet",
			TotalRequests:      2,
			SuccessCount:       1,
			FailureCount:       1,
			InputTokens:        30,
			OutputTokens:       9,
			ReasoningTokens:    2,
			CachedTokens:       1,
			TotalTokens:        42,
			TotalLatencyMS:     350,
			LatencySampleCount: 2,
		}},
	}}
	router := NewRouter(nil, nil, provider, nil, AuthConfig{}, nil, "")
	req := httptest.NewRequest(http.MethodGet, "/api/v1/usage/analysis?range=24h", nil)
	resp := httptest.NewRecorder()

	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", resp.Code)
	}
	body := resp.Body.String()
	if !contains(body, `"apis":[`) || !contains(body, `"models":[`) {
		t.Fatalf("unexpected response body: %s", body)
	}
	if !contains(body, `"display_name":"prov**er-a"`) {
		t.Fatalf("expected display name in response body: %s", body)
	}
	if !contains(body, `"api_key":"`+redact.APIAlias("provider-a")+`"`) {
		t.Fatalf("expected redacted api key alias in response body: %s", body)
	}
	if !contains(body, `"model":"claude-sonnet"`) || !contains(body, `"latency_sample_count":2`) || !contains(body, `"total_latency_ms":350`) {
		t.Fatalf("expected model latency aggregates in response body: %s", body)
	}
	if provider.analysisCalls != 1 {
		t.Fatalf("expected GetUsageAnalysis to be called once, got %d", provider.analysisCalls)
	}
	if provider.lastFilter.Range != "24h" {
		t.Fatalf("expected range to be passed through, got %+v", provider.lastFilter)
	}
	if provider.lastFilter.StartTime == nil || provider.lastFilter.EndTime == nil {
		t.Fatalf("expected resolved time bounds in filter, got %+v", provider.lastFilter)
	}
}

func TestUsageAnalysisRequiresAuthWhenEnabled(t *testing.T) {
	router := NewRouter(nil, nil, &usageAnalysisStub{}, nil, AuthConfig{Enabled: true, LoginPassword: "secret", SessionTTL: time.Hour}, nil, "")
	req := httptest.NewRequest(http.MethodGet, "/api/v1/usage/analysis", nil)
	resp := httptest.NewRecorder()

	router.ServeHTTP(resp, req)

	if resp.Code != http.StatusUnauthorized {
		t.Fatalf("expected status 401, got %d", resp.Code)
	}
}