package openai

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	edgeservice "iop/apps/edge/internal/service"
	"iop/packages/go/config"
	iop "iop/proto/gen/iop"
)

func TestHandleModelsProviderPoolCatalog(t *testing.T) {
	catalog := []config.ModelCatalogEntry{
		{ID: "qwen3.6:35b", Providers: map[string]string{"prov-1": "Qwen3-35B-A22B"}},
		{ID: "llama3.3:70b", Providers: map[string]string{"prov-2": "llama-3.3-70b"}},
	}
	srv := NewServer(config.EdgeOpenAIConf{
		ModelRoutes: []config.OpenAIRouteEntry{
			{Model: "legacy-model", Target: "legacy-target"},
		},
	}, &fakeRunService{}, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	w := httptest.NewRecorder()
	srv.handleModels(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	body := w.Body.String()
	if !strings.Contains(body, "qwen3.6:35b") || !strings.Contains(body, "llama3.3:70b") {
		t.Fatalf("catalog models not listed: %s", body)
	}
	if strings.Contains(body, "legacy-model") {
		t.Fatalf("legacy model_routes should be suppressed when catalog is set: %s", body)
	}
}

// TestChatCompletionsProviderPoolDispatch verifies that when a request model
// matches the provider-pool catalog with omitted response mode, the request is
// dispatched over the provider tunnel with ProviderPool=true and Adapter/Target
// left empty for service-layer resolution (pure passthrough default, SDD D02).
func TestChatCompletionsProviderPoolDispatch(t *testing.T) {
	frames := make(chan *iop.ProviderTunnelFrame, 3)
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_RESPONSE_START, StatusCode: 200}
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_BODY, Body: []byte(`{"ok":true}`)}
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_END, End: true}
	close(frames)
	fake := &providerFakeRunService{
		tunnelFrames: frames,
	}

	catalog := []config.ModelCatalogEntry{
		{ID: "qwen3.6:35b", Providers: map[string]string{"prov-vllm": "Qwen3-35B-A22B"}},
	}
	srv := NewServer(config.EdgeOpenAIConf{}, fake, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
		"model":"qwen3.6:35b",
		"messages":[{"role":"user","content":"hello"}]
	}`))
	w := httptest.NewRecorder()
	srv.handleChatCompletions(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	tunnelReqs := fake.tunnelReqsSnapshot()
	if len(tunnelReqs) != 1 {
		t.Fatalf("expected 1 tunnel dispatch, got %d (SubmitRun calls: %d)", len(tunnelReqs), len(fake.reqsSnapshot()))
	}
	treq := tunnelReqs[0]
	if !treq.ProviderPool {
		t.Error("ProviderPool should be true for catalog-matched model")
	}
	if treq.ModelGroupKey != "qwen3.6:35b" {
		t.Errorf("ModelGroupKey: got %q, want qwen3.6:35b", treq.ModelGroupKey)
	}
	if treq.Adapter != "" || treq.Target != "" {
		t.Errorf("Adapter/Target should be empty for provider-pool dispatch, got %q/%q", treq.Adapter, treq.Target)
	}
	if treq.Method != http.MethodPost || treq.Path != "/v1/chat/completions" {
		t.Errorf("tunnel method/path: got %q %q", treq.Method, treq.Path)
	}
	if len(fake.reqsSnapshot()) != 0 {
		t.Errorf("normalized SubmitRun must not be called for omitted-mode provider route")
	}
}

func TestChatCompletionsStrictOutputProviderPoolDefaultKeepsPassthroughPath(t *testing.T) {
	frames := make(chan *iop.ProviderTunnelFrame, 3)
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_RESPONSE_START, StatusCode: 200}
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_BODY, Body: []byte(`{"ok":true}`)}
	frames <- &iop.ProviderTunnelFrame{Kind: iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_END, End: true}
	close(frames)
	fake := &providerFakeRunService{
		tunnelFrames: frames,
	}

	catalog := []config.ModelCatalogEntry{
		{ID: "qwen3.6:35b", Providers: map[string]string{"prov-vllm": "Qwen3-35B-A22B"}},
	}
	srv := NewServer(config.EdgeOpenAIConf{StrictOutput: true}, fake, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
		"model":"qwen3.6:35b",
		"messages":[{"role":"user","content":"hello"}],
		"include_reasoning": true
	}`))
	w := httptest.NewRecorder()
	srv.handleChatCompletions(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	if len(fake.tunnelReqsSnapshot()) != 1 {
		t.Fatalf("strict output default must keep provider routes on passthrough, got %d tunnel dispatches", len(fake.tunnelReqsSnapshot()))
	}
	if len(fake.reqsSnapshot()) != 0 {
		t.Fatalf("strict output provider route must not fall back to normalized SubmitRun, got %d calls", len(fake.reqsSnapshot()))
	}
}

// TestChatCompletionsProviderPoolIgnoresSelectorLikeMetadata verifies SDD S01:
// arbitrary caller metadata — including keys or values that resemble a legacy
// response-mode selector — is opaque context. It never rejects the request or
// switches a provider-pool route off pure passthrough. (The former selector key
// literal is deliberately not used here; the deterministic surface check forbids
// it anywhere under apps.)
func TestChatCompletionsProviderPoolIgnoresSelectorLikeMetadata(t *testing.T) {
	cases := []struct {
		name     string
		metadata string
	}{
		{name: "selector-like value is ignored", metadata: `"metadata":{"response_hint":"raw"}`},
		{name: "arbitrary metadata is ignored", metadata: `"metadata":{"experiment":"mode-x","team":"search"}`},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			providerBody := `{"ok":true}`
			fake := &providerFakeRunService{
				poolDispatchPath: string(edgeservice.ProviderPoolPathTunnel),
				tunnelFrames:     staticProviderTunnelFrames(providerBody),
			}
			srv := NewServer(config.EdgeOpenAIConf{}, fake, nil)
			srv.SetModelCatalog([]config.ModelCatalogEntry{
				{ID: "pool-model", Providers: map[string]string{"prov-1": "served-model"}},
			})

			body := `{
				"model":"pool-model",
				"messages":[{"role":"user","content":"hello"}],
				` + tc.metadata + `
			}`
			req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(body))
			w := httptest.NewRecorder()
			srv.handleChatCompletions(w, req)

			if w.Code != http.StatusOK {
				t.Fatalf("selector-like metadata must not be rejected: got %d body=%s", w.Code, w.Body.String())
			}
			if got := w.Body.String(); got != providerBody {
				t.Fatalf("provider body must be relayed byte-identically: got %q want %q", got, providerBody)
			}
			if len(fake.tunnelReqsSnapshot()) != 1 {
				t.Fatalf("expected 1 pure passthrough tunnel dispatch, got %d", len(fake.tunnelReqsSnapshot()))
			}
			if len(fake.reqsSnapshot()) != 0 {
				t.Fatalf("arbitrary metadata must not switch to normalized SubmitRun, got %d", len(fake.reqsSnapshot()))
			}
		})
	}
}

// TestChatCompletionsLegacyRouteSetsProviderPoolFalse verifies that when the
// server is configured with Adapter + Target (no catalog), the dispatched
// SubmitRunRequest has ProviderPool=false so the service uses direct dispatch
// (not the queue admission gate that requires ProviderPool=true).
func TestChatCompletionsLegacyRouteSetsProviderPoolFalse(t *testing.T) {
	fake := &fakeRunService{events: make(chan *iop.RunEvent, 2)}
	fake.events <- &iop.RunEvent{Type: "delta", Delta: "hi"}
	fake.events <- &iop.RunEvent{Type: "complete"}

	// Server with adapter+target only, no catalog — classic legacy route.
	srv := NewServer(config.EdgeOpenAIConf{
		Adapter:    "cli",
		Target:     "codex",
		TimeoutSec: 10,
	}, fake, nil)

	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
		"model":"any-model",
		"messages":[{"role":"user","content":"hello"}]
	}`))
	w := httptest.NewRecorder()
	srv.handleChatCompletions(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	if fake.req.ProviderPool {
		t.Error("ProviderPool must be false for a legacy adapter+target route with no catalog")
	}
	if fake.req.Adapter != "cli" || fake.req.Target != "codex" {
		t.Errorf("Adapter/Target: got %q/%q, want cli/codex", fake.req.Adapter, fake.req.Target)
	}
}

// TestResponsesProviderPoolDispatch verifies that /v1/responses sends
// provider-pool models through the raw provider tunnel (POST /v1/responses)
// instead of the normalized RunEvent path.
func TestResponsesProviderPoolDispatch(t *testing.T) {
	fake := &providerFakeRunService{
		tunnelFrames:       staticProviderTunnelFrames(`{"id":"resp-1","object":"response"}`),
		tunnelServedTarget: "model-a",
	}
	catalog := []config.ModelCatalogEntry{
		{ID: "prov-vllm:model-a", Providers: map[string]string{"prov-vllm": "model-a"}},
	}
	srv := NewServer(config.EdgeOpenAIConf{TimeoutSec: 5}, fake, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodPost, "/v1/responses", strings.NewReader(`{
		"model":"prov-vllm:model-a",
		"input":"hello"
	}`))
	w := httptest.NewRecorder()
	srv.handleResponses(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	if len(fake.reqsSnapshot()) != 0 {
		t.Fatalf("provider-pool /v1/responses must not call SubmitRun, got %d calls", len(fake.reqsSnapshot()))
	}
	reqs := fake.tunnelReqsSnapshot()
	if len(reqs) != 1 {
		t.Fatalf("expected 1 tunnel dispatch, got %d", len(reqs))
	}
	if reqs[0].Path != "/v1/responses" {
		t.Fatalf("tunnel path: got %q want /v1/responses", reqs[0].Path)
	}
	if reqs[0].Method != http.MethodPost {
		t.Fatalf("tunnel method: got %q want POST", reqs[0].Method)
	}
}

// TestResponsesProviderPoolPreservesRawOutputTokens verifies that raw
// passthrough preserves the caller's Responses-shaped max_output_tokens and does
// not inject the Chat-shaped max_tokens or generation policy.
func TestResponsesProviderPoolPreservesRawOutputTokens(t *testing.T) {
	fake := &providerFakeRunService{
		tunnelFrames:       staticProviderTunnelFrames(`{"ok":true}`),
		tunnelServedTarget: "Ornith-1.0-35B",
	}
	catalog := []config.ModelCatalogEntry{{
		ID:                         "ornith:35b",
		DefaultMaxTokens:           32768,
		MinMaxTokens:               32768,
		DefaultThinkingTokenBudget: 8192,
		Providers:                  map[string]string{"prov-vllm": "Ornith-1.0-35B"},
	}}
	srv := NewServer(config.EdgeOpenAIConf{TimeoutSec: 5}, fake, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodPost, "/v1/responses", strings.NewReader(`{
		"model":"ornith:35b",
		"input":"hello",
		"max_output_tokens":4096
	}`))
	w := httptest.NewRecorder()
	srv.handleResponses(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	if len(fake.reqsSnapshot()) != 0 {
		t.Fatalf("provider-pool /v1/responses must not call SubmitRun, got %d calls", len(fake.reqsSnapshot()))
	}
	bodies := fake.tunnelBodiesSnapshot()
	if len(bodies) != 1 {
		t.Fatalf("expected 1 tunnel body, got %d", len(bodies))
	}
	var providerReq map[string]any
	if err := json.Unmarshal(bodies[0], &providerReq); err != nil {
		t.Fatalf("provider body JSON: %v body=%s", err, bodies[0])
	}
	if providerReq["model"] != "Ornith-1.0-35B" {
		t.Fatalf("served model rewrite not applied: %+v", providerReq["model"])
	}
	if providerReq["max_output_tokens"].(float64) != 4096 {
		t.Fatalf("caller max_output_tokens must be preserved: %+v", providerReq)
	}
	if _, ok := providerReq["max_tokens"]; ok {
		t.Fatalf("passthrough must not inject Chat-shaped max_tokens: %+v", providerReq)
	}
	if _, ok := providerReq["thinking_token_budget"]; ok {
		t.Fatalf("passthrough must not inject thinking_token_budget: %+v", providerReq)
	}
}

// TestResponsesProviderPoolIgnoresSelectorLikeMetadata verifies SDD S01/S04 for
// /v1/responses: arbitrary caller metadata never rejects the request or moves a
// provider route off pure passthrough. (The former selector key literal is
// deliberately not used; the deterministic surface check forbids it under apps.)
func TestResponsesProviderPoolIgnoresSelectorLikeMetadata(t *testing.T) {
	cases := []struct {
		name     string
		metadata string
	}{
		{name: "selector-like value is ignored", metadata: `"metadata":{"response_hint":"raw"}`},
		{name: "arbitrary metadata is ignored", metadata: `"metadata":{"experiment":"mode-x"}`},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			providerBody := `{"ok":true}`
			srv, fake := responsesProviderTunnelServer(staticProviderTunnelFrames(providerBody), "served-model")
			req := httptest.NewRequest(http.MethodPost, "/v1/responses", strings.NewReader(fmt.Sprintf(`{
				"model":"pool-model",
				"input":"hi",
				%s
			}`, tc.metadata)))
			w := httptest.NewRecorder()
			srv.handleResponses(w, req)

			if w.Code != http.StatusOK {
				t.Fatalf("selector-like metadata must not be rejected: got %d body=%s", w.Code, w.Body.String())
			}
			if got := w.Body.String(); got != providerBody {
				t.Fatalf("provider body must be relayed byte-identically: got %q want %q", got, providerBody)
			}
			if len(fake.tunnelReqsSnapshot()) != 1 {
				t.Fatalf("expected 1 pure passthrough tunnel dispatch, got %d", len(fake.tunnelReqsSnapshot()))
			}
			if len(fake.reqsSnapshot()) != 0 {
				t.Fatalf("responses provider route must not call SubmitRun, got %d", len(fake.reqsSnapshot()))
			}
		})
	}
}

func TestChatCompletionsProviderPoolFallsBackToLegacyRoute(t *testing.T) {
	fake := &fakeRunService{events: make(chan *iop.RunEvent, 2)}
	fake.events <- &iop.RunEvent{Type: "delta", Delta: "ok"}
	fake.events <- &iop.RunEvent{Type: "complete"}

	catalog := []config.ModelCatalogEntry{
		{ID: "qwen3.6:35b", Providers: map[string]string{"prov-vllm": "Qwen3-35B-A22B"}},
	}
	srv := NewServer(config.EdgeOpenAIConf{
		ModelRoutes: []config.OpenAIRouteEntry{
			{Model: "ollama-model", Adapter: "ollama", Target: "llama3"},
		},
	}, fake, nil)
	srv.SetModelCatalog(catalog)

	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
		"model":"ollama-model",
		"messages":[{"role":"user","content":"hi"}]
	}`))
	w := httptest.NewRecorder()
	srv.handleChatCompletions(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}
	if fake.req.ProviderPool {
		t.Error("ProviderPool should be false for non-catalog model")
	}
	if fake.req.Target != "llama3" {
		t.Errorf("Target: got %q, want llama3", fake.req.Target)
	}
}

// TestProviderPoolStandardResponseNoExtensionFields verifies that a
// provider-pool tunnel passthrough standard response carries only
// provider-original bytes and no IOP extension fields or response-mode label
// (SURFACE_OBS-2/3 regression).
func TestProviderPoolStandardResponseNoExtensionFields(t *testing.T) {
	providerBody := `{"choices":[{"message":{"role":"assistant","content":"hello provider"}}],"usage":{"prompt_tokens":5,"completion_tokens":3}}`
	frames := staticProviderTunnelFrames(providerBody)

	fake := &providerFakeRunService{
		poolDispatchPath: "provider_tunnel",
		tunnelFrames:     frames,
	}
	srv := NewServer(config.EdgeOpenAIConf{
		PrincipalTokens: []config.OpenAIPrincipalTokenConf{
			{TokenRef: "iop-tok-alice", TokenHashSHA256: sha256Hex("sk-no-sb-token"), PrincipalRef: "user:alice", PrincipalAlias: "alice"},
		},
	}, fake, nil)
	srv.SetEdgeID("edge-no-sb")
	srv.SetModelCatalog([]config.ModelCatalogEntry{
		{ID: "sb-model", Providers: map[string]string{"prov-sb": "served-sb"}},
	})

	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
		"model":"sb-model",
		"messages":[{"role":"user","content":"hi"}]
	}`))
	req.Header.Set("Authorization", "Bearer sk-no-sb-token")
	w := httptest.NewRecorder()
	srv.routes().ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: got %d body=%s", w.Code, w.Body.String())
	}

	// Response body must be the provider-original JSON with only the model
	// field rewritten, carrying no IOP extension markers.
	body := w.Body.String()
	if strings.Contains(body, "iop_") || strings.Contains(body, "iop.") {
		t.Errorf("standard response must not contain IOP extension markers: %s", body)
	}

	// Verify the tunnel was dispatched.
	if len(fake.tunnelReqsSnapshot()) == 0 {
		t.Error("expected provider tunnel dispatch")
	}
}