package generator

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/emicklei/proto"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	conf "github.com/zeromicro/go-zero/tools/goctl/config"
	"github.com/zeromicro/go-zero/tools/goctl/rpc/parser"
	"github.com/zeromicro/go-zero/tools/goctl/util/stringx"
)

// mockDirContext is a minimal DirContext for unit-testing genCallGroup.
type mockDirContext struct {
	callDir Dir
	pbDir   Dir
	protoGo Dir
}

func (m *mockDirContext) GetCall() Dir                   { return m.callDir }
func (m *mockDirContext) GetEtc() Dir                    { return Dir{} }
func (m *mockDirContext) GetInternal() Dir               { return Dir{} }
func (m *mockDirContext) GetConfig() Dir                 { return Dir{} }
func (m *mockDirContext) GetLogic() Dir                  { return Dir{} }
func (m *mockDirContext) GetServer() Dir                 { return Dir{} }
func (m *mockDirContext) GetSvc() Dir                    { return Dir{} }
func (m *mockDirContext) GetPb() Dir                     { return m.pbDir }
func (m *mockDirContext) GetProtoGo() Dir                { return m.protoGo }
func (m *mockDirContext) GetMain() Dir                   { return Dir{} }
func (m *mockDirContext) GetServiceName() stringx.String { return stringx.From("test") }
func (m *mockDirContext) SetPbDir(pbDir, grpcDir string) {}

// TestGenCallGroup_OnlyUsedTypesAliased verifies that in multi-service mode each
// generated client file contains type aliases only for the message types actually
// used by that service's RPCs (fix for issue #5481).
func TestGenCallGroup_OnlyUsedTypesAliased(t *testing.T) {
	tmpDir := t.TempDir()
	callBase := filepath.Join(tmpDir, "call")
	pbBase := filepath.Join(tmpDir, "pb")

	// Pre-create subdirs that genCallGroup will write into.
	require.NoError(t, os.MkdirAll(filepath.Join(callBase, "servicea"), 0755))
	require.NoError(t, os.MkdirAll(filepath.Join(callBase, "serviceb"), 0755))
	require.NoError(t, os.MkdirAll(pbBase, 0755))

	mctx := &mockDirContext{
		callDir: Dir{
			Filename: callBase,
			Package:  "example.com/multitest/call",
			Base:     "call",
			GetChildPackage: func(childPath string) (string, error) {
				// Return a package path whose Base() is the lowercase service name.
				return filepath.Join(callBase, strings.ToLower(childPath)), nil
			},
		},
		pbDir: Dir{
			Filename: pbBase,
			Package:  "example.com/multitest/pb",
			Base:     "pb",
		},
		protoGo: Dir{
			// Must differ from "servicea"/"serviceb" so isCallPkgSameToPbPkg stays false
			// and alias generation is triggered.
			Filename: pbBase,
			Package:  "example.com/multitest/pb",
			Base:     "pb",
		},
	}

	// Proto with two services that use completely disjoint message types.
	protoData := parser.Proto{
		Name:      "multi.proto",
		PbPackage: "pb",
		Message: []parser.Message{
			{Message: &proto.Message{Name: "AReq"}},
			{Message: &proto.Message{Name: "AResp"}},
			{Message: &proto.Message{Name: "BReq"}},
			{Message: &proto.Message{Name: "BResp"}},
		},
		Service: parser.Services{
			{
				Service: &proto.Service{Name: "ServiceA"},
				RPC: []*parser.RPC{
					{RPC: &proto.RPC{Name: "DoA", RequestType: "AReq", ReturnsType: "AResp"}},
				},
			},
			{
				Service: &proto.Service{Name: "ServiceB"},
				RPC: []*parser.RPC{
					{RPC: &proto.RPC{Name: "DoB", RequestType: "BReq", ReturnsType: "BResp"}},
				},
			},
		},
	}

	cfg, err := conf.NewConfig("")
	require.NoError(t, err)

	g := NewGenerator("gozero", false)
	require.NoError(t, g.genCallGroup(mctx, protoData, cfg))

	// servicea/servicea.go — aliases for AReq/AResp only
	aContent, err := os.ReadFile(filepath.Join(callBase, "servicea", "servicea.go"))
	require.NoError(t, err)
	aFile := normalizeWS(string(aContent))

	assert.Contains(t, aFile, "AReq = pb.AReq", "ServiceA file should alias AReq")
	assert.Contains(t, aFile, "AResp = pb.AResp", "ServiceA file should alias AResp")
	assert.NotContains(t, aFile, "BReq = pb.BReq", "ServiceA file must not alias BReq")
	assert.NotContains(t, aFile, "BResp = pb.BResp", "ServiceA file must not alias BResp")

	// serviceb/serviceb.go — aliases for BReq/BResp only
	bContent, err := os.ReadFile(filepath.Join(callBase, "serviceb", "serviceb.go"))
	require.NoError(t, err)
	bFile := normalizeWS(string(bContent))

	assert.Contains(t, bFile, "BReq = pb.BReq", "ServiceB file should alias BReq")
	assert.Contains(t, bFile, "BResp = pb.BResp", "ServiceB file should alias BResp")
	assert.NotContains(t, bFile, "AReq = pb.AReq", "ServiceB file must not alias AReq")
	assert.NotContains(t, bFile, "AResp = pb.AResp", "ServiceB file must not alias AResp")
}

// normalizeWS replaces runs of whitespace with a single space.
func normalizeWS(s string) string {
	return strings.Join(strings.Fields(strings.ReplaceAll(s, "\n", " \n ")), " ")
}