package modeladapter

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

func TestProvidersForwardAuthenticationOverridesAndFinishStream(t *testing.T) {
	for _, provider := range []string{"openai", "anthropic"} {
		t.Run(provider, func(t *testing.T) {
			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				if r.Header.Get("X-Gateway-Key") != "fixture-gateway" || r.Host != "gateway.fixture" {
					t.Error("custom headers not applied")
				}
				if provider == "openai" && r.Header.Get("Authorization") != "Bearer fixture-key" {
					t.Error("OpenAI authentication missing")
				}
				if provider == "anthropic" && r.Header.Get("x-api-key") != "fixture-key" {
					t.Error("Anthropic authentication missing")
				}
				var body map[string]any
				if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
					t.Error(err)
				}
				if body["model"] != "fixture-model" {
					t.Error("model mapping lost")
				}
				w.Header().Set("Content-Type", "text/event-stream")
				if provider == "openai" {
					fmt.Fprint(w, "data: {\"choices\":[{\"delta\":{\"content\":\"ok\"},\"finish_reason\":null}]}\n\ndata: {\"choices\":[{\"delta\":{},\"finish_reason\":\"stop\"}],\"usage\":{\"prompt_tokens\":1,\"completion_tokens\":1}}\n\ndata: [DONE]\n\n")
				} else {
					for _, event := range []string{`{"type":"message_start","message":{"id":"fixture","type":"message","role":"assistant","content":[],"model":"fixture-model","usage":{"input_tokens":1,"output_tokens":0}}}`, `{"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}`, `{"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"ok"}}`, `{"type":"content_block_stop","index":0}`, `{"type":"message_delta","delta":{"stop_reason":"end_turn","stop_sequence":null},"usage":{"output_tokens":1}}`, `{"type":"message_stop"}`} {
						var envelope struct {
							Type string `json:"type"`
						}
						_ = json.Unmarshal([]byte(event), &envelope)
						fmt.Fprintf(w, "event: %s\ndata: %s\n\n", envelope.Type, event)
					}
				}
			}))
			defer server.Close()
			req := StreamRequest{BaseURL: server.URL, APIKey: "fixture-key", ProviderModelID: "fixture-model", ModelID: "fixture-model", OpenAIEndpoint: "/v1/chat/completions", Messages: []Message{{Role: "user", Content: "hello"}}, MaxTokens: 32, Stream: true, CustomHeadersEnabled: true, CustomHeadersJSON: `{"X-Gateway-Key":"fixture-gateway","Host":"gateway.fixture"}`}
			var text strings.Builder
			finished := false
			sink := func(event ModelEvent) error {
				if event.Kind == ModelEventKindTextDelta {
					text.WriteString(event.Text)
				}
				if event.Kind == ModelEventKindTurnFinished {
					finished = true
				}
				return nil
			}
			ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
			defer cancel()
			var err error
			if provider == "openai" {
				adapter := NewOpenAIAdapter()
				adapter.client = server.Client()
				err = adapter.Stream(ctx, req, sink)
			} else {
				adapter := NewAnthropicAdapter()
				adapter.client = server.Client()
				err = adapter.Stream(ctx, req, sink)
			}
			if err != nil {
				t.Fatal(err)
			}
			if text.String() != "ok" || !finished {
				t.Fatalf("stream did not finish correctly: %q %t", text.String(), finished)
			}
		})
	}
}

func TestProviderDeadlineCancelsPendingHTTPResponse(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = io.Copy(io.Discard, r.Body); <-r.Context().Done() }))
	defer server.Close()
	ctx, cancel := context.WithTimeout(context.Background(), 25*time.Millisecond)
	defer cancel()
	_, err := DoProviderRequestWithRetry(ctx, server.Client(), "fixture", "", "", func(ctx context.Context) (*http.Request, error) {
		return http.NewRequestWithContext(ctx, http.MethodPost, server.URL, strings.NewReader("fixture"))
	})
	if err == nil || ctx.Err() == nil {
		t.Fatal("provider ignored cancellation")
	}
}