package testkit_test

import (
	"bytes"
	"encoding/hex"
	"encoding/json"
	"testing"

	"g.activething.com/go/DateKeys/internal/testkit"
)

func TestEdits(t *testing.T) {
	base := []byte("0123456789")
	for _, tc := range []struct {
		out  string
		want string // JSON of Splice(base, out)
	}{
		{"0123456789", `[]`},
		{"01X3456789", `[[2,1,"58"]]`},
		{"012", `[[3,7,""]]`},
		{"", `[[0,10,""]]`},
		{"01234567890", `[[10,0,"30"]]`},
		{"0123XY456789", `[[4,0,"5859"]]`},
	} {
		edits := testkit.Splice(base, []byte(tc.out))
		if edits == nil {
			edits = []testkit.Edit{}
		}
		b, err := json.Marshal(edits)
		if err != nil || string(b) != tc.want {
			t.Errorf("Splice(%q) = %s, %v; want %s", tc.out, b, err, tc.want)
		}
		var back []testkit.Edit
		if err := json.Unmarshal(b, &back); err != nil {
			t.Fatal(err)
		}
		out, err := testkit.ApplyEdits(base, back)
		if err != nil || string(out) != tc.out {
			t.Errorf("ApplyEdits(%s) = %q, %v; want %q", b, out, err, tc.out)
		}
	}
	// Several edits refer to offsets of the base.
	out, err := testkit.ApplyEdits(base, []testkit.Edit{{At: 1, Delete: 1, Insert: []byte("ab")}, {At: 5, Delete: 2}, {At: 10, Insert: []byte("!")}})
	if err != nil || string(out) != "0ab234789!" {
		t.Fatalf("got %q, %v", out, err)
	}
	for _, bad := range [][]testkit.Edit{
		{{At: 5, Delete: 1}, {At: 2, Delete: 1}}, // out of order
		{{At: 2, Delete: 3}, {At: 4, Delete: 1}}, // overlapping
		{{At: 9, Delete: 2}},                     // beyond the base
		{{At: -1}},
	} {
		if _, err := testkit.ApplyEdits(base, bad); err == nil {
			t.Errorf("ApplyEdits accepted %v", bad)
		}
	}
	for _, bad := range []string{`[1,2]`, `[1,2,"zz"]`, `["1",2,""]`, `{}`} {
		var e testkit.Edit
		if err := json.Unmarshal([]byte(bad), &e); err == nil {
			t.Errorf("Edit accepted %s", bad)
		}
	}
}

// The schema vectors of testdata/vectors/cbor.json replay: the decoder of each
// schema gives exactly the recorded result.
func TestSchemaVectors(t *testing.T) {
	var f testkit.CBORVectorFile
	if err := testkit.ReadJSON("../../testdata/vectors/cbor.json", &f); err != nil {
		t.Fatal(err)
	}
	blocks := map[string]int{}
	for _, v := range f.Schemas {
		b, err := hex.DecodeString(v.Hex)
		if err != nil {
			t.Fatal(err)
		}
		if got := testkit.Result(testkit.DecodeSchema(v.Schema, b)); got != v.Result {
			t.Errorf("%s %q: got %s, want %s", v.Block, v.Name, got, v.Result)
		}
		blocks[v.Block]++
	}
	for _, b := range []string{testkit.SchemaProfile, testkit.SchemaHeader, testkit.SchemaControl, testkit.SchemaDKKBody, "verification_metadata", "extension"} {
		if blocks[b] < 5 {
			t.Errorf("block %s has %d vectors", b, blocks[b])
		}
	}
	if err := testkit.DecodeSchema("nope", nil); err == nil {
		t.Error("unknown schema accepted")
	}
}

// The committed vector files are what the generators compute now.
func TestVectorFilesAreCurrent(t *testing.T) {
	want, err := testkit.CBORVectors()
	if err != nil {
		t.Fatal(err)
	}
	var got testkit.CBORVectorFile
	if err := testkit.ReadJSON("../../testdata/vectors/cbor.json", &got); err != nil {
		t.Fatal(err)
	}
	a, _ := json.Marshal(want)
	b, _ := json.Marshal(got)
	if !bytes.Equal(a, b) {
		t.Error("testdata/vectors/cbor.json is stale: run go run ./internal/testkit/genfixtures -out testdata")
	}
}