// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package postgres

import (
	"context"
	"sort"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/experiment"
	"golang.org/x/pkgsite/internal/testing/sample"
)

func TestInsertSymbolNamesAndHistory(t *testing.T) {
	t.Parallel()
	testDB, release := acquire(t)
	defer release()
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	ctx = experiment.NewContext(ctx,
		internal.ExperimentReadSymbolHistory,
		internal.ExperimentInsertSymbolHistory,
	)
	defer cancel()

	mod := sample.DefaultModule()
	if len(mod.Packages()) != 1 {
		t.Fatalf("len(mod.Packages()) = %d; want 1", len(mod.Packages()))
	}
	if len(mod.Packages()[0].Documentation) != 1 {
		t.Fatalf("len(mod.Packages()[0].Documentation) = %d; want 1", len(mod.Packages()[0].Documentation))
	}
	api := []*internal.Symbol{
		sample.Constant,
		sample.Variable,
		sample.Function,
		sample.Type,
	}
	mod.Packages()[0].Documentation[0].API = api
	MustInsertModule(ctx, t, testDB, mod)

	got, err := collectStrings(ctx, testDB.db, `SELECT name FROM symbol_names;`)
	if err != nil {
		t.Fatal(err)
	}
	want := []string{
		sample.Constant.Name,
		sample.Variable.Name,
		sample.Function.Name,
		sample.Type.Name,
	}
	for _, c := range sample.Type.Children {
		want = append(want, c.Name)
	}
	sort.Strings(got)
	sort.Strings(want)
	if diff := cmp.Diff(want, got); diff != "" {
		t.Errorf("mismatch (-want +got):\n%s", diff)
	}
	compareUnitSymbols(ctx, t, testDB, mod.Packages()[0].Path, mod.ModulePath, mod.Version,
		map[internal.BuildContext][]*internal.Symbol{internal.BuildContextAll: api})
	want2 := map[string]map[string]*internal.UnitSymbol{}
	want2[mod.Version] = unitSymbolsFromAPI(api, mod.Version)
	comparePackageSymbols(ctx, t, testDB, mod.Packages()[0].Path, mod.ModulePath, mod.Version, want2)

	gotHist, err := testDB.LegacyGetSymbolHistory(ctx, mod.Packages()[0].Path, mod.ModulePath)
	if err != nil {
		t.Fatal(err)
	}
	wantHist := map[string]map[string]*internal.UnitSymbol{
		"v1.0.0": map[string]*internal.UnitSymbol{
			"Constant":    unitSymbolFromSymbol(sample.Constant, "v1.0.0"),
			"Variable":    unitSymbolFromSymbol(sample.Variable, "v1.0.0"),
			"Function":    unitSymbolFromSymbol(sample.Function, "v1.0.0"),
			"Type":        unitSymbolFromSymbol(sample.Type, "v1.0.0"),
			"Type.Field":  unitSymbolFromSymbolMeta(sample.Type.Children[0], "v1.0.0", internal.BuildContextAll),
			"New":         unitSymbolFromSymbolMeta(sample.Type.Children[1], "v1.0.0", internal.BuildContextAll),
			"Type.Method": unitSymbolFromSymbolMeta(sample.Type.Children[2], "v1.0.0", internal.BuildContextAll),
		},
	}
	if diff := cmp.Diff(wantHist, gotHist,
		cmp.AllowUnexported(internal.UnitSymbol{})); diff != "" {
		t.Fatalf("mismatch on symbol history(-want +got):\n%s", diff)
	}
}

func TestInsertSymbolHistory_Basic(t *testing.T) {
	testDB, release := acquire(t)
	defer release()
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	ctx = experiment.NewContext(ctx,
		internal.ExperimentReadSymbolHistory,
		internal.ExperimentInsertSymbolHistory,
	)
	defer cancel()

	mod := sample.DefaultModule()
	if len(mod.Packages()) != 1 {
		t.Fatalf("len(mod.Packages()) = %d; want 1", len(mod.Packages()))
	}
	if len(mod.Packages()[0].Documentation) != 1 {
		t.Fatalf("len(mod.Packages()[0].Documentation) = %d; want 1", len(mod.Packages()[0].Documentation))
	}
	api := []*internal.Symbol{
		sample.Constant,
		sample.Variable,
		sample.Function,
		sample.Type,
	}
	mod.Packages()[0].Documentation[0].API = api
	MustInsertModule(ctx, t, testDB, mod)

	compareUnitSymbols(ctx, t, testDB, mod.Packages()[0].Path, mod.ModulePath, mod.Version,
		map[internal.BuildContext][]*internal.Symbol{internal.BuildContextAll: api})
	want2 := map[string]map[string]*internal.UnitSymbol{}
	want2[mod.Version] = unitSymbolsFromAPI(api, mod.Version)
	comparePackageSymbols(ctx, t, testDB, mod.Packages()[0].Path, mod.ModulePath, mod.Version, want2)
}

func TestInsertSymbolHistory_MultiVersions(t *testing.T) {
	testDB, release := acquire(t)
	defer release()
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	ctx = experiment.NewContext(ctx,
		internal.ExperimentReadSymbolHistory,
		internal.ExperimentInsertSymbolHistory,
	)
	defer cancel()

	typ := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo",
			Synopsis:   "type Foo struct",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindType,
			ParentName: "Foo",
		},
	}
	methodA := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo.A",
			Synopsis:   "func (*Foo) A()",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindMethod,
			ParentName: typ.Name,
		},
	}
	methodB := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo.B",
			Synopsis:   "func (*Foo) B()",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindMethod,
			ParentName: typ.Name,
		},
	}
	typA := typ
	typA.Children = []*internal.SymbolMeta{&methodA.SymbolMeta}
	typB := typ
	typB.Children = []*internal.SymbolMeta{&methodA.SymbolMeta, &methodB.SymbolMeta}

	mod10 := moduleWithSymbols(t, "v1.0.0", []*internal.Symbol{&typ})
	mod11 := moduleWithSymbols(t, "v1.1.0", []*internal.Symbol{&typA})
	mod12 := moduleWithSymbols(t, "v1.2.0", []*internal.Symbol{&typB})

	// Insert most recent, then oldest, then middle version.
	MustInsertModule(ctx, t, testDB, mod12)
	MustInsertModule(ctx, t, testDB, mod10)
	MustInsertModule(ctx, t, testDB, mod11)

	createwant := func(docs []*internal.Documentation) map[internal.BuildContext][]*internal.Symbol {
		want := map[internal.BuildContext][]*internal.Symbol{}
		for _, doc := range docs {
			want[internal.BuildContext{GOOS: doc.GOOS, GOARCH: doc.GOARCH}] = doc.API
		}
		return want
	}

	want10 := createwant(mod10.Packages()[0].Documentation)
	want11 := createwant(mod11.Packages()[0].Documentation)
	want12 := createwant(mod12.Packages()[0].Documentation)
	compareUnitSymbols(ctx, t, testDB, mod10.Packages()[0].Path, mod10.ModulePath, mod10.Version, want10)
	compareUnitSymbols(ctx, t, testDB, mod11.Packages()[0].Path, mod11.ModulePath, mod11.Version, want11)
	compareUnitSymbols(ctx, t, testDB, mod12.Packages()[0].Path, mod12.ModulePath, mod12.Version, want12)

	want2 := map[string]map[string]*internal.UnitSymbol{}
	for _, want := range []struct {
		version        string
		buildToSymbols map[internal.BuildContext][]*internal.Symbol
	}{
		{mod10.Version, want10},
		{mod11.Version, want11},
		{mod12.Version, want12},
	} {
		for _, api := range want.buildToSymbols {
			want2[want.version] = unitSymbolsFromAPI(api, want.version)
		}
	}
	comparePackageSymbols(ctx, t, testDB, mod10.Packages()[0].Path, mod10.ModulePath, mod10.Version, want2)

	gotHist, err := testDB.LegacyGetSymbolHistory(ctx, mod10.Packages()[0].Path, mod10.ModulePath)
	if err != nil {
		t.Fatal(err)
	}
	typA.GOOS = internal.All
	methodA.GOOS = internal.All
	methodB.GOOS = internal.All
	typA.GOARCH = internal.All
	methodA.GOARCH = internal.All
	methodB.GOARCH = internal.All
	wantHist := map[string]map[string]*internal.UnitSymbol{
		"v1.0.0": map[string]*internal.UnitSymbol{
			"Foo": unitSymbolFromSymbol(&typA, "v1.0.0"),
		},
		"v1.1.0": {
			"Foo.A": unitSymbolFromSymbol(&methodA, "v1.1.0"),
		},
		"v1.2.0": {
			"Foo.B": unitSymbolFromSymbol(&methodB, "v1.2.0"),
		},
	}
	if diff := cmp.Diff(wantHist, gotHist,
		cmp.AllowUnexported(internal.UnitSymbol{})); diff != "" {
		t.Fatalf("mismatch on symbol history(-want +got):\n%s", diff)
	}
}

func TestInsertSymbolHistory_MultiGOOS(t *testing.T) {
	testDB, release := acquire(t)
	defer release()
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	ctx = experiment.NewContext(ctx,
		internal.ExperimentReadSymbolHistory,
		internal.ExperimentInsertSymbolHistory,
	)
	defer cancel()

	typ := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo",
			Synopsis:   "type Foo struct",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindType,
			ParentName: "Foo",
		},
	}
	methodA := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo.A",
			Synopsis:   "func (*Foo) A()",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindMethod,
			ParentName: typ.Name,
		},
	}
	methodB := internal.Symbol{
		SymbolMeta: internal.SymbolMeta{
			Name:       "Foo.B",
			Synopsis:   "func (*Foo) B()",
			Section:    internal.SymbolSectionTypes,
			Kind:       internal.SymbolKindMethod,
			ParentName: typ.Name,
		},
	}
	mod10 := moduleWithSymbols(t, "v1.0.0", []*internal.Symbol{&typ})
	mod11 := moduleWithSymbols(t, "v1.1.0", nil)
	makeDocs := func() []*internal.Documentation {
		return []*internal.Documentation{
			sample.Documentation(
				internal.BuildContextLinux.GOOS,
				internal.BuildContextLinux.GOARCH,
				sample.DocContents),
			sample.Documentation(
				internal.BuildContextWindows.GOOS,
				internal.BuildContextWindows.GOARCH,
				sample.DocContents),
			sample.Documentation(
				internal.BuildContextDarwin.GOOS,
				internal.BuildContextDarwin.GOARCH,
				sample.DocContents),
			sample.Documentation(
				internal.BuildContextJS.GOOS,
				internal.BuildContextJS.GOARCH,
				sample.DocContents),
		}
	}
	mod11.Packages()[0].Documentation = makeDocs()
	docs1 := mod11.Packages()[0].Documentation

	symsA := []internal.Symbol{methodA}
	symsB := []internal.Symbol{methodB}
	createType := func(methods []internal.Symbol, goos, goarch string) []*internal.Symbol {
		newTyp := typ
		newTyp.GOOS = goos
		newTyp.GOARCH = goarch

		for _, m := range methods {
			m.GOOS = goos
			m.GOARCH = goarch
			newTyp.Children = append(newTyp.Children, &m.SymbolMeta)
		}
		return []*internal.Symbol{&newTyp}
	}
	docs1[0].API = createType(symsA, docs1[0].GOOS, docs1[0].GOARCH)
	docs1[1].API = createType(symsA, docs1[1].GOOS, docs1[1].GOARCH)
	docs1[2].API = createType(symsB, docs1[2].GOOS, docs1[2].GOARCH)
	docs1[3].API = createType(symsB, docs1[3].GOOS, docs1[3].GOARCH)
	mod11.Packages()[0].Documentation = docs1

	mod12 := moduleWithSymbols(t, "v1.2.0", nil)
	mod12.Packages()[0].Documentation = makeDocs()
	docs2 := mod12.Packages()[0].Documentation
	docs2[0].API = createType(symsB, docs2[0].GOOS, docs2[0].GOARCH)
	docs2[1].API = createType(symsB, docs2[1].GOOS, docs2[1].GOARCH)
	docs2[2].API = createType(symsA, docs2[2].GOOS, docs2[2].GOARCH)
	docs2[3].API = createType(symsA, docs2[3].GOOS, docs2[3].GOARCH)
	mod12.Packages()[0].Documentation = docs2

	// Insert most recent, then oldest, then middle version.
	MustInsertModule(ctx, t, testDB, mod12)
	MustInsertModule(ctx, t, testDB, mod10)
	MustInsertModule(ctx, t, testDB, mod11)

	createwant := func(docs []*internal.Documentation) map[internal.BuildContext][]*internal.Symbol {
		want := map[internal.BuildContext][]*internal.Symbol{}
		for _, doc := range docs {
			want[internal.BuildContext{GOOS: doc.GOOS, GOARCH: doc.GOARCH}] = doc.API
		}
		return want
	}
	want10 := createwant(mod10.Packages()[0].Documentation)
	want11 := createwant(mod11.Packages()[0].Documentation)
	want12 := createwant(mod12.Packages()[0].Documentation)
	compareUnitSymbols(ctx, t, testDB, mod10.Packages()[0].Path, mod10.ModulePath, mod10.Version, want10)
	compareUnitSymbols(ctx, t, testDB, mod11.Packages()[0].Path, mod11.ModulePath, mod11.Version, want11)
	compareUnitSymbols(ctx, t, testDB, mod12.Packages()[0].Path, mod12.ModulePath, mod12.Version, want12)

	want2 := map[string]map[string]*internal.UnitSymbol{}
	for _, mod := range []*internal.Module{mod10, mod11, mod12} {
		want2[mod.Version] = map[string]*internal.UnitSymbol{}
		for _, pkg := range mod.Packages() {
			for _, doc := range pkg.Documentation {
				nameToUnitSym := unitSymbolsFromAPI(doc.API, mod.Version)
				for name, unitSym := range nameToUnitSym {
					if _, ok := want2[mod.Version][name]; !ok {
						want2[mod.Version][name] = unitSym
					}
				}
			}
		}
	}
	comparePackageSymbols(ctx, t, testDB, mod10.Packages()[0].Path, mod10.ModulePath, mod10.Version, want2)

	gotHist, err := testDB.LegacyGetSymbolHistory(ctx, mod10.Packages()[0].Path, mod10.ModulePath)
	if err != nil {
		t.Fatal(err)
	}

	typ.GOOS = internal.All
	typ.GOARCH = internal.All
	wantHist := map[string]map[string]*internal.UnitSymbol{
		"v1.0.0": map[string]*internal.UnitSymbol{
			"Foo": unitSymbolFromSymbol(&typ, "v1.0.0"),
		},
		"v1.1.0": map[string]*internal.UnitSymbol{
			"Foo.A": func() *internal.UnitSymbol {
				us := unitSymbolFromSymbol(&methodA, "v1.1.0")
				us.RemoveBuildContexts()
				us.AddBuildContext(internal.BuildContextLinux)
				us.AddBuildContext(internal.BuildContextWindows)
				return us
			}(),
			"Foo.B": func() *internal.UnitSymbol {
				us := unitSymbolFromSymbol(&methodB, "v1.1.0")
				us.RemoveBuildContexts()
				us.AddBuildContext(internal.BuildContextJS)
				us.AddBuildContext(internal.BuildContextDarwin)
				return us
			}(),
		},
		"v1.2.0": map[string]*internal.UnitSymbol{
			"Foo.A": func() *internal.UnitSymbol {
				us := unitSymbolFromSymbol(&methodA, "v1.2.0")
				us.RemoveBuildContexts()
				us.AddBuildContext(internal.BuildContextJS)
				us.AddBuildContext(internal.BuildContextDarwin)
				return us
			}(),
			"Foo.B": func() *internal.UnitSymbol {
				us := unitSymbolFromSymbol(&methodB, "v1.2.0")
				us.RemoveBuildContexts()
				us.AddBuildContext(internal.BuildContextLinux)
				us.AddBuildContext(internal.BuildContextWindows)
				return us
			}(),
		},
	}
	if diff := cmp.Diff(wantHist, gotHist,
		cmp.AllowUnexported(internal.UnitSymbol{})); diff != "" {
		t.Fatalf("mismatch on symbol history(-want +got):\n%s", diff)
	}

	pathID, err := getPathID(ctx, testDB.db, mod10.Packages()[0].Path)
	if err != nil {
		t.Fatal(err)
	}
	gotHist2, err := getSymbolHistoryForBuildContext(ctx, testDB.db,
		pathID, mod10.ModulePath, internal.BuildContextWindows)
	if err != nil {
		t.Fatal(err)
	}
	wantHist2 := map[string]string{
		"Foo":   "v1.0.0",
		"Foo.A": "v1.1.0",
		"Foo.B": "v1.2.0",
	}
	if diff := cmp.Diff(wantHist2, gotHist2); diff != "" {
		t.Fatalf("mismatch on symbol history(-want +got):\n%s", diff)
	}
}

func moduleWithSymbols(t *testing.T, version string, symbols []*internal.Symbol) *internal.Module {
	mod := sample.Module(sample.ModulePath, version, "")
	if len(mod.Packages()) != 1 {
		t.Fatalf("len(mod.Packages()) = %d; want 1", len(mod.Packages()))
	}
	if len(mod.Packages()[0].Documentation) != 1 {
		t.Fatalf("len(mod.Packages()[0].Documentation) = %d; want 1", len(mod.Packages()[0].Documentation))
	}
	// symbols for goos/goarch = all/all
	mod.Packages()[0].Documentation[0].API = symbols
	return mod
}

func compareUnitSymbols(ctx context.Context, t *testing.T, testDB *DB,
	path, modulePath, version string, wantBuildToSymbols map[internal.BuildContext][]*internal.Symbol) {
	t.Helper()
	unitID, err := testDB.getUnitID(ctx, path, modulePath, version)
	if err != nil {
		t.Fatal(err)
	}
	buildToSymbols, err := getUnitSymbols(ctx, testDB.db, unitID)
	if err != nil {
		t.Fatal(err)
	}
	for build, got := range buildToSymbols {
		want := wantBuildToSymbols[build]
		sort.Slice(got, func(i, j int) bool {
			return got[i].Synopsis < got[j].Synopsis
		})
		for _, s := range got {
			sort.Slice(s.Children, func(i, j int) bool {
				return s.Children[i].Synopsis < s.Children[j].Synopsis
			})
		}
		sort.Slice(want, func(i, j int) bool {
			return want[i].Synopsis < want[j].Synopsis
		})
		for _, s := range want {
			sort.Slice(s.Children, func(i, j int) bool {
				return s.Children[i].Synopsis < s.Children[j].Synopsis
			})
		}
		if diff := cmp.Diff(want, got,
			cmpopts.IgnoreFields(internal.Symbol{}, "GOOS", "GOARCH")); diff != "" {
			t.Fatalf("mismatch (-want +got):\n%s", diff)
		}
	}
}

func comparePackageSymbols(ctx context.Context, t *testing.T, testDB *DB,
	path, modulePath, version string, want map[string]map[string]*internal.UnitSymbol) {
	t.Helper()
	got, err := legacyGetPackageSymbols(ctx, testDB.db, path, modulePath)
	if err != nil {
		t.Fatal(err)
	}
	if diff := cmp.Diff(want, got,
		cmpopts.IgnoreFields(internal.UnitSymbol{}, "builds")); diff != "" {
		t.Errorf("mismatch (-want +got):\n%s", diff)
	}
}

func unitSymbolsFromAPI(api []*internal.Symbol, version string) map[string]*internal.UnitSymbol {
	nameToUnitSymbols := map[string]*internal.UnitSymbol{}
	updateSymbols(api, func(s *internal.SymbolMeta) error {
		if _, ok := nameToUnitSymbols[s.Name]; !ok {
			us := unitSymbolFromSymbolMeta(s, version, internal.BuildContextAll)
			nameToUnitSymbols[s.Name] = us
		}
		return nil
	})
	return nameToUnitSymbols
}

func unitSymbolFromSymbol(s *internal.Symbol, version string) *internal.UnitSymbol {
	us := &internal.UnitSymbol{
		SymbolMeta: s.SymbolMeta,
	}
	us.AddBuildContext(internal.BuildContext{GOOS: s.GOOS, GOARCH: s.GOARCH})
	return us
}

func unitSymbolFromSymbolMeta(sm *internal.SymbolMeta, version string, b internal.BuildContext) *internal.UnitSymbol {
	us := &internal.UnitSymbol{
		SymbolMeta: *sm,
	}
	us.AddBuildContext(b)
	return us
}