package errcode

import (
	"encoding/json"
	"errors"
	"fmt"
	"testing"
)

func sampleDef(code Code) Definition {
	return Definition{
		Code:        code,
		HTTP:        503,
		Severity:    SeverityError,
		Retry:       RetryTransient,
		SideEffects: SideEffectNone,
		Summary:     "提供方不可用",
		Hint:        "退避后重试",
		Aliases:     []string{"provider_unavailable"},
	}
}

func TestCodeFormat(t *testing.T) {
	ok := []Code{SysInternal, AgentProviderUnavailable, SquadRoleNotFound, "custom-domain.snake_name"}
	for _, c := range ok {
		if !c.Valid() {
			t.Fatalf("%s should be valid", c)
		}
		if c.Domain() == "" || c.Mnemonic() == "" {
			t.Fatalf("%s domain/mnemonic empty", c)
		}
	}
	bad := []Code{"", "NoDot", "A.b", "sys.", ".internal", "sys.Internal", "1sys.internal", "sys.a"}
	for _, c := range bad {
		if c.Valid() {
			t.Fatalf("%s should be invalid", c)
		}
	}
}

func TestRegisterLookupAliasResolve(t *testing.T) {
	r := NewRegistry()
	def := sampleDef(AgentProviderUnavailable)
	if err := r.Register(def); err != nil {
		t.Fatal(err)
	}
	if err := r.Register(def); err == nil {
		t.Fatal("duplicate register should fail")
	}
	got, ok := r.Lookup("provider_unavailable")
	if !ok || got.Code != AgentProviderUnavailable {
		t.Fatalf("alias lookup: %+v ok=%v", got, ok)
	}
	if err := r.Alias("TRANSIENT", AgentProviderUnavailable); err != nil {
		t.Fatal(err)
	}
	if _, ok := r.Lookup("TRANSIENT"); !ok {
		t.Fatal("added alias missing")
	}
	unknown := r.Resolve("not.a.real")
	if unknown.Code != SysUnknownCode {
		t.Fatalf("resolve fallback = %s", unknown.Code)
	}
	if r.Known("not.a.real") {
		t.Fatal("unknown should not be known")
	}
	if !r.Known(string(AgentProviderUnavailable)) {
		t.Fatal("canonical should be known")
	}
}

func TestRegisterRejectsBadAliasAndRollsBack(t *testing.T) {
	r := NewRegistry()
	def := sampleDef(AgentTimeout)
	def.Aliases = []string{"ok_alias", "bad alias"}
	if err := r.Register(def); err == nil {
		t.Fatal("expected invalid alias")
	}
	if r.Known(string(AgentTimeout)) || r.Known("ok_alias") {
		t.Fatal("failed register must not leave partial state")
	}
}

func TestLoadJSONRollback(t *testing.T) {
	r := NewRegistry()
	raw := []byte(`[
		{"code":"demo.one","http":400,"severity":"warn","retry":"never","side_effects":"none","summary":"一","hint":"检查"},
		{"code":"demo.one","http":400,"severity":"warn","retry":"never","side_effects":"none","summary":"重复","hint":"检查"}
	]`)
	if err := r.LoadJSON(raw); err == nil {
		t.Fatal("expected duplicate failure")
	}
	if len(r.List("")) != 0 {
		t.Fatal("batch should roll back")
	}
	wrapped := []byte(`{"codes":[{"code":"demo.two","http":404,"severity":"info","retry":"never","side_effects":"none","summary":"没有","hint":"确认标识"}]}`)
	if err := r.LoadJSON(wrapped); err != nil {
		t.Fatal(err)
	}
	if !r.Known("demo.two") {
		t.Fatal("wrapped catalog not loaded")
	}
}

func TestSearchAndExport(t *testing.T) {
	r := NewRegistry()
	if err := r.Register(sampleDef(AgentProviderUnavailable)); err != nil {
		t.Fatal(err)
	}
	found := r.Search("不可用")
	if len(found) != 1 {
		t.Fatalf("search %d", len(found))
	}
	data, err := r.ExportJSON()
	if err != nil {
		t.Fatal(err)
	}
	var defs []Definition
	if err := json.Unmarshal(data, &defs); err != nil {
		t.Fatal(err)
	}
	if len(defs) != 1 || defs[0].Code != AgentProviderUnavailable {
		t.Fatalf("export %+v", defs)
	}
}

func TestErrorWrapIsAsJSON(t *testing.T) {
	root := fmt.Errorf("connection reset")
	err := Wrap(root, AgentProviderUnavailable, "模型不可达", "model", "glm-4")
	if !errors.Is(err, New(AgentProviderUnavailable, "")) {
		t.Fatal("errors.Is should match code")
	}
	if !errors.Is(err, root) {
		t.Fatal("errors.Is should see cause")
	}
	var got *E
	if !errors.As(err, &got) {
		t.Fatal("errors.As")
	}
	if From(fmt.Errorf("wrap: %w", err)).Code != AgentProviderUnavailable {
		t.Fatal("From should walk the chain")
	}
	if err.ErrorCode() != string(AgentProviderUnavailable) {
		t.Fatal(err.ErrorCode())
	}
	fields := err.ErrorFields()
	if fields["model"] != "glm-4" || fields["reason"] != "模型不可达" {
		t.Fatalf("fields %+v", fields)
	}
	fields["model"] = "mutated"
	if err.ErrorFields()["model"] != "glm-4" {
		t.Fatal("ErrorFields must return a copy")
	}
	if Wrap(nil, SysInternal, "x") != nil {
		t.Fatal("Wrap(nil) must be nil")
	}
	data, errJSON := json.Marshal(err)
	if errJSON != nil {
		t.Fatal(errJSON)
	}
	var back E
	if err := json.Unmarshal(data, &back); err != nil {
		t.Fatal(err)
	}
	if back.Code != AgentProviderUnavailable || back.Unwrap() == nil || back.Unwrap().Error() != root.Error() {
		t.Fatalf("roundtrip %+v cause=%v", back, back.Unwrap())
	}
}

func TestPanicOnOddFields(t *testing.T) {
	defer func() {
		if recover() == nil {
			t.Fatal("expected panic")
		}
	}()
	New(SysInternal, "x", "only-key")
}