package majordomo

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

	"gitea.stevedudenhoeffer.com/steve/majordomo/llm"
)

// qwenResponse is a minimal valid Chat Completions body so Generate returns a
// non-empty response (an empty one would trigger failover, not a clean pass).
const qwenResponse = `{"id":"c1","object":"chat.completion","choices":[` +
	`{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}]}`

// TestQwenBuiltin: the built-in "qwen" provider resolves in Parse, targets
// Model Studio's international OpenAI-compatible endpoint, and authenticates
// with QWEN_API_KEY.
func TestQwenBuiltin(t *testing.T) {
	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t,
		WithEnvLookup(func(k string) string {
			if k == "QWEN_API_KEY" {
				return "qwen-secret"
			}
			return ""
		}),
		WithHTTPClient(&http.Client{Transport: rt}),
	)

	if p, ok := r.Provider(ProviderQwen); !ok {
		t.Fatal("built-in qwen provider not registered")
	} else if p.Name() != ProviderQwen {
		t.Errorf("name = %q, want %q", p.Name(), ProviderQwen)
	}

	m, err := r.Parse("qwen/qwen3-max")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	if got := targetsOf(t, m); len(got) != 1 || got[0] != "qwen/qwen3-max" {
		t.Fatalf("targets = %v", got)
	}

	if _, err := m.Generate(context.Background(), llm.Request{Messages: []llm.Message{llm.UserText("hi")}}); err != nil {
		t.Fatalf("Generate: %v", err)
	}
	if rt.req == nil {
		t.Fatal("no request captured")
	}
	if want := "https://dashscope-intl.aliyuncs.com/compatible-mode/v1/chat/completions"; rt.req.URL.String() != want {
		t.Errorf("URL = %q, want %q", rt.req.URL.String(), want)
	}
	if want := "Bearer qwen-secret"; rt.req.Header.Get("Authorization") != want {
		t.Errorf("Authorization = %q, want %q", rt.req.Header.Get("Authorization"), want)
	}
}

// TestQwenBuiltinMissingKey: with no QWEN_API_KEY the built-in fails fast with
// a synthetic 401 whose hint names QWEN_API_KEY — never OPENAI_API_KEY (proving
// the credential does not fall through to the openai client's default), and
// without hitting the network.
func TestQwenBuiltinMissingKey(t *testing.T) {
	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t, WithHTTPClient(&http.Client{Transport: rt}))

	m, err := r.Parse("qwen/qwen3-max")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	_, err = m.Generate(context.Background(), llm.Request{Messages: []llm.Message{llm.UserText("hi")}})
	apiErr, ok := errors.AsType[*llm.APIError](err)
	if !ok {
		t.Fatalf("err = %v (%T), want *llm.APIError", err, err)
	}
	if apiErr.Status != http.StatusUnauthorized || apiErr.Code != "missing_api_key" {
		t.Errorf("Status/Code = %d/%q, want 401/missing_api_key", apiErr.Status, apiErr.Code)
	}
	if !strings.Contains(apiErr.Message, "QWEN_API_KEY") {
		t.Errorf("message = %q, want it to name QWEN_API_KEY", apiErr.Message)
	}
	if strings.Contains(apiErr.Message, "OPENAI_API_KEY") {
		t.Errorf("message = %q, must not name OPENAI_API_KEY", apiErr.Message)
	}
	if rt.req != nil {
		t.Error("network was hit despite missing key")
	}
}

// TestQwenBuiltinKeyDoesNotLeakToOpenAI: QWEN_API_KEY is the qwen built-in's
// credential and nothing else's. Why this direction too: the fallthrough guard
// only proves qwen never borrows OPENAI_API_KEY; this proves the reverse — a
// registry that can see QWEN_API_KEY must not hand it to the openai built-in,
// which would send an Alibaba key to api.openai.com.
func TestQwenBuiltinKeyDoesNotLeakToOpenAI(t *testing.T) {
	// Set before newTestRegistry: the openai built-in reads OPENAI_API_KEY at
	// construction. Giving it a real key is what keeps this test honest — a
	// keyless openai target would 401 before any request, and the assertion
	// below would pass without a single byte reaching the wire.
	t.Setenv("OPENAI_API_KEY", "openai-secret")

	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t,
		WithEnvLookup(func(k string) string {
			if k == "QWEN_API_KEY" {
				return "qwen-secret"
			}
			return ""
		}),
		WithHTTPClient(&http.Client{Transport: rt}),
	)

	m, err := r.Parse("openai/gpt-4o-mini")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	if _, err := m.Generate(context.Background(), llm.Request{Messages: []llm.Message{llm.UserText("hi")}}); err != nil {
		t.Fatalf("Generate: %v", err)
	}
	if rt.req == nil {
		t.Fatal("no request captured")
	}
	if want := "Bearer openai-secret"; rt.req.Header.Get("Authorization") != want {
		t.Errorf("Authorization = %q, want %q — the qwen credential must not reach the openai built-in",
			rt.req.Header.Get("Authorization"), want)
	}
}

// TestQwenScheme: a qwen:// LLM_* DSN defines a named provider on any Model
// Studio host (here the China endpoint) that is first-class in Parse and
// carries the DSN token as its bearer credential.
func TestQwenScheme(t *testing.T) {
	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t, WithHTTPClient(&http.Client{Transport: rt}))
	if err := r.LoadEnv(map[string]string{
		"LLM_QCN": "qwen://tok@dashscope.aliyuncs.com/compatible-mode/v1",
	}); err != nil {
		t.Fatalf("LoadEnv: %v", err)
	}

	m, err := r.Parse("qcn/qwen-plus")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	if _, err := m.Generate(context.Background(), llm.Request{Messages: []llm.Message{llm.UserText("hi")}}); err != nil {
		t.Fatalf("Generate: %v", err)
	}
	if rt.req == nil {
		t.Fatal("no request captured")
	}
	if want := "https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions"; rt.req.URL.String() != want {
		t.Errorf("URL = %q, want %q", rt.req.URL.String(), want)
	}
	if want := "Bearer tok"; rt.req.Header.Get("Authorization") != want {
		t.Errorf("Authorization = %q, want %q", rt.req.Header.Get("Authorization"), want)
	}
}

// TestQwenSchemeMissingToken: a qwen:// DSN with no token is fixed by adding
// one to the DSN, not by setting QWEN_API_KEY — so the missing-key hint names
// the defining LLM_<NAME> env var, never QWEN_API_KEY (which does nothing for a
// DSN-defined provider).
func TestQwenSchemeMissingToken(t *testing.T) {
	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t, WithHTTPClient(&http.Client{Transport: rt}))
	if err := r.LoadEnv(map[string]string{
		"LLM_QCN": "qwen://dashscope.aliyuncs.com/compatible-mode/v1", // no token
	}); err != nil {
		t.Fatalf("LoadEnv: %v", err)
	}

	m, err := r.Parse("qcn/qwen-plus")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	_, err = m.Generate(context.Background(), llm.Request{Messages: []llm.Message{llm.UserText("hi")}})
	apiErr, ok := errors.AsType[*llm.APIError](err)
	if !ok {
		t.Fatalf("err = %v (%T), want *llm.APIError", err, err)
	}
	if !strings.Contains(apiErr.Message, "LLM_QCN") {
		t.Errorf("message = %q, want it to name LLM_QCN", apiErr.Message)
	}
	if strings.Contains(apiErr.Message, "QWEN_API_KEY") {
		t.Errorf("message = %q, must not name QWEN_API_KEY for a DSN provider", apiErr.Message)
	}
	if rt.req != nil {
		t.Error("network was hit despite missing token")
	}
}

// TestQwenReasoningEffortReachesWire is the load-bearing test for ADR-0027's
// central claim: Model Studio's OpenAI-compatible surface takes reasoning as a
// top-level "reasoning_effort" body field, which the openai client already
// sends — so llm.WithReasoningEffort survives the trip on qwen with no
// qwen-specific code. Routing qwen through the anthropic client instead would
// drop it silently (provider/anthropic ignores ReasoningEffort by design), and
// that difference would be invisible without asserting on the wire body.
func TestQwenReasoningEffortReachesWire(t *testing.T) {
	rt := &captureRT{body: qwenResponse}
	r := newTestRegistry(t,
		WithEnvLookup(func(k string) string {
			if k == "QWEN_API_KEY" {
				return "qwen-secret"
			}
			return ""
		}),
		WithHTTPClient(&http.Client{Transport: rt}),
	)

	m, err := r.Parse("qwen/qwen3-max")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	_, err = m.Generate(context.Background(), llm.Request{
		Messages:        []llm.Message{llm.UserText("hi")},
		ReasoningEffort: "high",
	})
	if err != nil {
		t.Fatalf("Generate: %v", err)
	}
	if rt.reqBody == nil {
		t.Fatal("no request body captured")
	}
	var sent map[string]any
	if err := json.Unmarshal(rt.reqBody, &sent); err != nil {
		t.Fatalf("decode request body: %v", err)
	}
	if got := sent["reasoning_effort"]; got != "high" {
		t.Errorf("reasoning_effort = %v, want %q (body: %s)", got, "high", rt.reqBody)
	}
}