package majordomo

import (
	"context"
	"errors"
	"io"
	"net/http"
	"strings"
	"testing"

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

// kimiResponse 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 kimiResponse = `{"id":"c1","object":"chat.completion","choices":[` +
	`{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}]}`

// captureRT records the last request and returns a canned response without
// touching the network, so these tests stay hermetic while still exercising
// the real openai client the kimi built-in reuses (base URL + auth header).
type captureRT struct {
	req  *http.Request
	body string
}

func (c *captureRT) RoundTrip(r *http.Request) (*http.Response, error) {
	c.req = r
	return &http.Response{
		StatusCode: http.StatusOK,
		Body:       io.NopCloser(strings.NewReader(c.body)),
		Header:     make(http.Header),
		Request:    r,
	}, nil
}

// TestKimiBuiltin: the built-in "kimi" provider resolves in Parse, targets
// Moonshot's default endpoint, and authenticates with KIMI_API_KEY.
func TestKimiBuiltin(t *testing.T) {
	rt := &captureRT{body: kimiResponse}
	r := newTestRegistry(t,
		WithEnvLookup(func(k string) string {
			if k == "KIMI_API_KEY" {
				return "kimi-secret"
			}
			return ""
		}),
		WithHTTPClient(&http.Client{Transport: rt}),
	)

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

	m, err := r.Parse("kimi/kimi-k2-0711-preview")
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	if got := targetsOf(t, m); len(got) != 1 || got[0] != "kimi/kimi-k2-0711-preview" {
		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://api.moonshot.ai/v1/chat/completions"; rt.req.URL.String() != want {
		t.Errorf("URL = %q, want %q", rt.req.URL.String(), want)
	}
	if want := "Bearer kimi-secret"; rt.req.Header.Get("Authorization") != want {
		t.Errorf("Authorization = %q, want %q", rt.req.Header.Get("Authorization"), want)
	}
}

// TestKimiBuiltinMissingKey: with no KIMI_API_KEY the built-in fails fast with a
// synthetic 401 whose hint names KIMI_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 TestKimiBuiltinMissingKey(t *testing.T) {
	rt := &captureRT{body: kimiResponse}
	r := newTestRegistry(t, WithHTTPClient(&http.Client{Transport: rt}))

	m, err := r.Parse("kimi/kimi-k2-0711-preview")
	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, "KIMI_API_KEY") {
		t.Errorf("message = %q, want it to name KIMI_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")
	}
}

// TestKimiScheme: a kimi:// LLM_* DSN defines a named provider on any Moonshot
// host (here the China endpoint) that is first-class in Parse and carries the
// DSN token as its bearer credential.
func TestKimiScheme(t *testing.T) {
	rt := &captureRT{body: kimiResponse}
	r := newTestRegistry(t, WithHTTPClient(&http.Client{Transport: rt}))
	if err := r.LoadEnv(map[string]string{
		"LLM_KCN": "kimi://tok@api.moonshot.cn/v1",
	}); err != nil {
		t.Fatalf("LoadEnv: %v", err)
	}

	m, err := r.Parse("kcn/moonshot-v1-8k")
	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://api.moonshot.cn/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)
	}
}

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

	m, err := r.Parse("kcn/moonshot-v1-8k")
	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_KCN") {
		t.Errorf("message = %q, want it to name LLM_KCN", apiErr.Message)
	}
	if strings.Contains(apiErr.Message, "KIMI_API_KEY") {
		t.Errorf("message = %q, must not name KIMI_API_KEY for a DSN provider", apiErr.Message)
	}
	if rt.req != nil {
		t.Error("network was hit despite missing token")
	}
}