package service

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

	"github.com/Wei-Shaw/sub2api/internal/config"
	"github.com/coder/websocket"
	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/require"
	"github.com/tidwall/gjson"
)

func TestBuildOpenAIWSCurrentTurnRetryPayloadRejectsOrphanToolOutput(t *testing.T) {
	payload := []byte(`{"type":"response.create","model":"mapped-model","previous_response_id":"resp_old"}`)
	fullInput := []json.RawMessage{
		json.RawMessage(`{"type":"function_call_output","call_id":"missing_call","output":"done"}`),
	}

	retryPayload, retrySafe, err := buildOpenAIWSCurrentTurnRetryPayload(payload, fullInput, true, "gpt-5.6-sol")

	require.NoError(t, err)
	require.False(t, retrySafe)
	require.Nil(t, retryPayload)
}

func TestProxyOpenAIWSHTTPBridgeTurnLaterTurn429FailsOverBeforeClientWrite(t *testing.T) {
	gin.SetMode(gin.TestMode)

	upstream := &httpUpstreamRecorder{resp: &http.Response{
		StatusCode: http.StatusTooManyRequests,
		Header:     http.Header{"Retry-After": []string{"60"}},
		Body:       io.NopCloser(strings.NewReader(`{"error":{"type":"usage_limit_reached","message":"The usage limit has been reached"}}`)),
	}}
	svc := &OpenAIGatewayService{cfg: &config.Config{}, httpUpstream: upstream}
	account := &Account{ID: 129, Platform: PlatformOpenAI, Type: AccountTypeOAuth, Concurrency: 1}
	recorder := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(recorder)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/responses", nil)
	payload := []byte(`{"type":"response.create","model":"gpt-5.6-sol","previous_response_id":"resp_old","input":[{"role":"user","content":"continue"}]}`)
	writes := 0

	result, err := svc.proxyOpenAIWSHTTPBridgeTurn(
		context.Background(), c, account, "access-token", payload, len(payload),
		"gpt-5.6-sol", "", "", "", "", 281,
		func([]byte) error {
			writes++
			return nil
		},
	)

	require.Nil(t, result)
	var failoverErr *UpstreamFailoverError
	require.ErrorAs(t, err, &failoverErr)
	require.Equal(t, http.StatusTooManyRequests, failoverErr.StatusCode)
	require.Zero(t, writes)
}

func TestProxyOpenAIWSHTTPBridgeTurnLaterTurnDoesNotFailOverAfterDownstreamOutput(t *testing.T) {
	gin.SetMode(gin.TestMode)

	upstream := &httpUpstreamRecorder{resp: &http.Response{
		StatusCode: http.StatusOK,
		Header:     make(http.Header),
		Body: io.NopCloser(strings.NewReader(
			"data: {\"type\":\"response.output_text.delta\",\"delta\":\"partial\"}\n\n" +
				"data: {\"type\":\"error\",\"error\":{\"type\":\"rate_limit_error\",\"message\":\"limited\"}}\n\n",
		)),
	}}
	svc := &OpenAIGatewayService{cfg: &config.Config{}, httpUpstream: upstream}
	account := &Account{ID: 10, Platform: PlatformOpenAI, Type: AccountTypeAPIKey, Concurrency: 1}
	recorder := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(recorder)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/responses", nil)
	payload := []byte(`{"type":"response.create","model":"gpt-5","input":"hi"}`)
	var writes [][]byte

	result, err := svc.proxyOpenAIWSHTTPBridgeTurn(
		context.Background(), c, account, "sk-test", payload, len(payload),
		"gpt-5", "", "", "", "", 281,
		func(message []byte) error {
			writes = append(writes, append([]byte(nil), message...))
			return nil
		},
	)

	require.NotNil(t, result)
	require.Error(t, err)
	var failoverErr *UpstreamFailoverError
	require.False(t, errors.As(err, &failoverErr))
	require.Len(t, writes, 2)
	require.Equal(t, "response.output_text.delta", gjson.GetBytes(writes[0], "type").String())
	require.Equal(t, "error", gjson.GetBytes(writes[1], "type").String())
}

func TestOpenAIWSHTTPBridgeLaterTurn429RetriesCurrentTurnOnReplacementAccount(t *testing.T) {
	gin.SetMode(gin.TestMode)

	cfg := &config.Config{}
	cfg.Security.URLAllowlist.Enabled = false
	cfg.Security.URLAllowlist.AllowInsecureHTTP = true
	cfg.Gateway.OpenAIWS.Enabled = true
	cfg.Gateway.OpenAIWS.OAuthEnabled = true
	cfg.Gateway.OpenAIWS.ResponsesWebsocketsV2 = true
	cfg.Gateway.OpenAIWS.ModeRouterV2Enabled = true
	cfg.Gateway.OpenAIWS.ReadTimeoutSeconds = 3
	cfg.Gateway.OpenAIWS.WriteTimeoutSeconds = 3

	upstream := &httpUpstreamRecorder{responses: []*http.Response{
		{
			StatusCode: http.StatusOK,
			Header: http.Header{
				"Content-Type":          []string{"text/event-stream"},
				openAIWSTurnStateHeader: []string{"old-account-state"},
			},
			Body: io.NopCloser(strings.NewReader(
				"data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_first\",\"output\":[{\"id\":\"msg_1\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"first-ok\"}]},{\"id\":\"fc_1\",\"type\":\"function_call\",\"call_id\":\"call_1\",\"name\":\"inspect\",\"arguments\":\"{}\"}],\"usage\":{\"input_tokens\":1,\"output_tokens\":1}}}\n\n",
			)),
		},
		{
			StatusCode: http.StatusTooManyRequests,
			Header:     http.Header{"Retry-After": []string{"60"}},
			Body:       io.NopCloser(strings.NewReader(`{"error":{"type":"usage_limit_reached","message":"The usage limit has been reached"}}`)),
		},
		{
			StatusCode: http.StatusOK,
			Header:     http.Header{"Content-Type": []string{"text/event-stream"}},
			Body: io.NopCloser(strings.NewReader(
				"data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_second\",\"output\":[{\"id\":\"msg_2\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"second-ok\"}]}],\"usage\":{\"input_tokens\":4,\"output_tokens\":1}}}\n\n",
			)),
		},
	}}
	svc := &OpenAIGatewayService{
		cfg:              cfg,
		httpUpstream:     upstream,
		cache:            &stubGatewayCache{},
		openaiWSResolver: NewOpenAIWSProtocolResolver(cfg),
		toolCorrector:    NewCodexToolCorrector(),
	}
	account := &Account{
		ID: 129, Name: "limited", Platform: PlatformOpenAI, Type: AccountTypeOAuth,
		Status: StatusActive, Schedulable: true, Concurrency: 1,
		Extra: map[string]any{"openai_oauth_responses_websockets_v2_mode": OpenAIWSIngressModeHTTPBridge},
	}
	nextAccount := *account
	nextAccount.ID = 130
	nextAccount.Name = "replacement"

	serverErrCh := make(chan error, 1)
	failoverCh := make(chan []byte, 1)
	wsServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		conn, err := websocket.Accept(w, r, nil)
		if err != nil {
			serverErrCh <- err
			return
		}
		defer func() { _ = conn.CloseNow() }()

		rec := httptest.NewRecorder()
		ginCtx, _ := gin.CreateTestContext(rec)
		ginCtx.Request = r.Clone(r.Context())
		readCtx, cancel := context.WithTimeout(r.Context(), 3*time.Second)
		_, firstMessage, readErr := conn.Read(readCtx)
		cancel()
		if readErr != nil {
			serverErrCh <- readErr
			return
		}
		proxyErr := svc.ProxyResponsesWebSocketFromClient(r.Context(), ginCtx, conn, account, "access-token-a", firstMessage, nil)
		var failoverErr *UpstreamFailoverError
		if !errors.As(proxyErr, &failoverErr) {
			serverErrCh <- proxyErr
			return
		}
		retryPayload, retryCurrentTurn := OpenAIWSCurrentTurnRetryPayload(proxyErr)
		if !retryCurrentTurn || len(retryPayload) == 0 {
			serverErrCh <- errors.New("missing current-turn retry payload")
			return
		}
		failoverCh <- retryPayload
		serverErrCh <- svc.ProxyResponsesWebSocketFromClient(
			r.Context(), ginCtx, conn, &nextAccount, "access-token-b", retryPayload, nil,
		)
	}))
	defer wsServer.Close()

	dialCtx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	clientConn, _, err := websocket.Dial(dialCtx, "ws"+strings.TrimPrefix(wsServer.URL, "http"), nil)
	cancel()
	require.NoError(t, err)
	defer func() { _ = clientConn.CloseNow() }()

	writeCtx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	err = clientConn.Write(writeCtx, websocket.MessageText, []byte(`{"type":"response.create","model":"gpt-5.6-sol","input":[{"role":"user","content":"first"}]}`))
	cancel()
	require.NoError(t, err)

	readCtx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	_, completed, err := clientConn.Read(readCtx)
	cancel()
	require.NoError(t, err)
	require.Equal(t, "response.completed", gjson.GetBytes(completed, "type").String())

	writeCtx, cancel = context.WithTimeout(context.Background(), 3*time.Second)
	err = clientConn.Write(writeCtx, websocket.MessageText, []byte(`{"type":"response.create","model":"gpt-5.6-sol","previous_response_id":"resp_first","input":[{"type":"function_call_output","call_id":"call_1","output":"second"}]}`))
	cancel()
	require.NoError(t, err)

	readCtx, cancel = context.WithTimeout(context.Background(), 3*time.Second)
	_, retriedCompleted, err := clientConn.Read(readCtx)
	cancel()
	require.NoError(t, err)
	require.Equal(t, "response.completed", gjson.GetBytes(retriedCompleted, "type").String())
	require.Equal(t, "resp_second", gjson.GetBytes(retriedCompleted, "response.id").String())
	_ = clientConn.Close(websocket.StatusNormalClosure, "done")

	select {
	case retryPayload := <-failoverCh:
		require.NotEmpty(t, retryPayload)
		require.False(t, gjson.GetBytes(retryPayload, "previous_response_id").Exists())
		require.Equal(t, "gpt-5.6-sol", gjson.GetBytes(retryPayload, "model").String())
		input := gjson.GetBytes(retryPayload, "input")
		require.True(t, input.IsArray())
		require.Len(t, input.Array(), 4)
		require.Contains(t, input.Raw, "first")
		require.Contains(t, input.Raw, "first-ok")
		require.Contains(t, input.Raw, "second")
		require.Equal(t, 1, strings.Count(input.Raw, `"id":"fc_1"`))
		require.Equal(t, 2, strings.Count(input.Raw, `"call_id":"call_1"`))
	case <-time.After(5 * time.Second):
		t.Fatal("timed out waiting for current-turn failover")
	}

	select {
	case proxyErr := <-serverErrCh:
		require.NoError(t, proxyErr)
	case <-time.After(5 * time.Second):
		t.Fatal("timed out waiting for replacement-account completion")
	}
	require.Len(t, upstream.bodies, 3)
	require.Contains(t, string(upstream.bodies[0]), "first")
	require.NotContains(t, string(upstream.bodies[2]), "previous_response_id")
	require.Contains(t, string(upstream.bodies[2]), "second")
	require.Empty(t, upstream.requests[2].Header.Get(openAIWSTurnStateHeader))
}