package httpx

import (
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	"error-code-system/domains"
	"error-code-system/errcode"
)

func TestTraceGeneratesAndEchoes(t *testing.T) {
	var seen string
	h := Trace(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		seen = TraceID(r)
		w.WriteHeader(http.StatusNoContent)
	}))

	req := httptest.NewRequest(http.MethodGet, "/", nil)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Header().Get(TraceHeader) == "" || seen != rec.Header().Get(TraceHeader) {
		t.Fatalf("generated trace header=%q seen=%q", rec.Header().Get(TraceHeader), seen)
	}

	req = httptest.NewRequest(http.MethodGet, "/", nil)
	req.Header.Set(TraceHeader, "trace-from-caller")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Header().Get(TraceHeader) != "trace-from-caller" {
		t.Fatalf("echo = %s", rec.Header().Get(TraceHeader))
	}

	req = httptest.NewRequest(http.MethodGet, "/", nil)
	req.Header.Set(TraceHeader, "bad id")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Header().Get(TraceHeader) == "bad id" || rec.Header().Get(TraceHeader) == "" {
		t.Fatal("invalid trace should be replaced")
	}
}

func TestWriteErrorEnvelope(t *testing.T) {
	reg := errcode.NewRegistry()
	domains.RegisterAll(reg)
	req := httptest.NewRequest(http.MethodGet, "/", nil)
	req.Header.Set(TraceHeader, "trace-abc-1234")
	rec := httptest.NewRecorder()
	err := errcode.Wrap(errors.New("dial timeout"), errcode.AgentProviderUnavailable, "模型不可达", "model", "glm-4")
	WriteError(reg, rec, req, err)
	if rec.Code != http.StatusServiceUnavailable {
		t.Fatalf("status %d", rec.Code)
	}
	var env Envelope
	if err := json.Unmarshal(rec.Body.Bytes(), &env); err != nil {
		t.Fatal(err)
	}
	if env.Error.Code != string(errcode.AgentProviderUnavailable) || env.Error.Message == "" {
		t.Fatalf("body %+v", env.Error)
	}
	if env.Error.Reason != "模型不可达" || env.Error.TraceID != "trace-abc-1234" {
		t.Fatalf("body %+v", env.Error)
	}
	if rec.Header().Get(TraceHeader) != "trace-abc-1234" {
		t.Fatal("trace header not echoed")
	}
}

func TestWriteErrorUnknownFallsBack(t *testing.T) {
	reg := errcode.NewRegistry()
	domains.RegisterAll(reg)
	rec := httptest.NewRecorder()
	WriteError(reg, rec, httptest.NewRequest(http.MethodGet, "/", nil), errcode.New("no.such_code", "x"))
	if rec.Code != http.StatusInternalServerError {
		t.Fatalf("status %d body %s", rec.Code, rec.Body.String())
	}
	var env Envelope
	if err := json.Unmarshal(rec.Body.Bytes(), &env); err != nil {
		t.Fatal(err)
	}
	if env.Error.Code != string(errcode.SysUnknownCode) {
		t.Fatalf("code %s", env.Error.Code)
	}
}