package skate

import (
	"bytes"
	"io/ioutil"
	"reflect"
	"testing"
	"time"

	"git.archive.org/martin/cgraph/skate/atomic"
	"git.archive.org/martin/cgraph/skate/xio"
	"github.com/kr/pretty"
)

func TestLineColumn(t *testing.T) {
	var cases = []struct {
		line   string
		sep    string
		column int
		result string
	}{
		{"", "", 2, ""},
		{"1 2 3", " ", 1, "1"},
		{"1 2 3", " ", 2, "2"},
		{"1 2 3", " ", 3, "3"},
		{"1 2 3", " ", 4, ""},
		{"1 2 3", "\t", 1, "1 2 3"},
	}
	for _, c := range cases {
		result := CutSep(c.line, c.sep, c.column)
		if result != c.result {
			t.Fatalf("got %v, want %v", result, c.result)
		}
	}
}

func TestCutBatch(t *testing.T) {
	var cases = []struct {
		lines  []string
		column int
		result []string
	}{
		{
			[]string{},
			1,
			nil,
		},
		{
			[]string{},
			9,
			nil,
		},
		{
			[]string{"1\t2\n", "3\t4\n"},
			2,
			[]string{"2", "4"},
		},
	}
	for _, c := range cases {
		result := CutBatch(c.lines, c.column)
		if !reflect.DeepEqual(result, c.result) {
			t.Fatalf("got %v (%d), want %v (%d)",
				result, len(result), c.result, len(c.result))
		}
	}
}

func TestUniqueMatches(t *testing.T) {
	var cases = []struct {
		about  string
		docs   []string
		result []*BiblioRef
		err    error
	}{
		{
			about:  "missing fields are ignored",
			docs:   []string{`{}`},
			result: []*BiblioRef{&BiblioRef{}},
			err:    nil,
		},
		{
			about: "a single doc is passed on",
			docs: []string{`{
			    "_id": "s1_0",
				"source_release_ident": "s1",
			    "target_release_ident": "t1"}`},
			result: []*BiblioRef{&BiblioRef{
				Key:                "s1_0",
				SourceReleaseIdent: "s1",
				TargetReleaseIdent: "t1",
			}},
			err: nil,
		},
		{
			about: "we want to keep the exact match, if available",
			docs: []string{`
			{"_id": "s1_0",
			 "source_release_ident": "s1",
			 "target_release_ident": "t1",
		     "match_status": "fuzzy"}`,
				`{"_id": "s1_1",
				  "source_release_ident": "s1",
			      "target_release_ident": "t1",
			      "match_status": "exact"}`,
			},
			result: []*BiblioRef{&BiblioRef{
				Key:                "s1_1",
				SourceReleaseIdent: "s1",
				TargetReleaseIdent: "t1",
				MatchStatus:        "exact",
			}},
			err: nil,
		},
		{
			about: "if both are exact, we just take (any) one",
			docs: []string{`
			{"_id": "s1_0",
			 "source_release_ident": "s1",
			 "target_release_ident": "t1",
		     "match_status": "exact",
			 "match_reason": "a"}`,
				`{"_id": "s1_1",
				  "source_release_ident": "s1",
			      "target_release_ident": "t1",
			      "match_status": "exact",
			      "match_reason": "b"}`,
			},
			result: []*BiblioRef{&BiblioRef{
				Key:                "s1_1",
				SourceReleaseIdent: "s1",
				TargetReleaseIdent: "t1",
				MatchStatus:        "exact",
				MatchReason:        "b",
			}},
			err: nil,
		},
		{
			about: "regression; a buggy sort?",
			docs: []string{`
			{"_id": "s1_0",
			 "source_release_ident": "s1",
			 "target_release_ident": "t1",
		     "match_status": "exact",
			 "match_reason": "a"}`,
				`{"_id": "s1_1",
				  "source_release_ident": "s1",
			      "target_release_ident": "t1",
			      "match_status": "fuzzy",
			      "match_reason": "b"}`,
			},
			result: []*BiblioRef{&BiblioRef{
				Key:                "s1_0",
				SourceReleaseIdent: "s1",
				TargetReleaseIdent: "t1",
				MatchStatus:        "exact",
				MatchReason:        "a",
			}},
			err: nil,
		},
	}
	for _, c := range cases {
		result, err := uniqueMatches(c.docs, &statsAugment{})
		if err != c.err {
			t.Fatalf("got %v, want %v (%s)", err, c.err, c.about)
		}
		if !reflect.DeepEqual(result, c.result) {
			t.Fatalf("got %#v, want %#v (%s)",
				pretty.Sprint(result),
				pretty.Sprint(c.result), c.about)
		}
	}
}

func TestMatchedRefsExtend(t *testing.T) {
	var cases = []struct {
		matched []*BiblioRef
		refs    []*Ref
		result  []*BiblioRef
	}{
		{
			matched: []*BiblioRef{},
			refs:    []*Ref{},
			result:  []*BiblioRef{},
		},
		{
			matched: []*BiblioRef{
				&BiblioRef{
					RefIndex: 2,
					RefKey:   "K2",
				},
			},
			refs: []*Ref{},
			result: []*BiblioRef{
				&BiblioRef{
					RefIndex: 2,
					RefKey:   "K2",
				},
			},
		},
		{
			matched: []*BiblioRef{
				&BiblioRef{
					SourceReleaseIdent: "pud5shsflfgrth77lmlernavjm",
					RefIndex:           2,
					RefKey:             "K2",
				},
			},
			refs: []*Ref{
				&Ref{
					ReleaseIdent: "0000",
					Biblio: Biblio{
						Title: "Title",
					},
					Index: 3,
					Key:   "K3",
				},
			},
			result: []*BiblioRef{
				&BiblioRef{
					SourceReleaseIdent: "pud5shsflfgrth77lmlernavjm",
					RefIndex:           2,
					RefKey:             "K2",
				},
				&BiblioRef{
					Key:                "0000_3",
					SourceReleaseIdent: "0000",
					RefIndex:           3,
					RefKey:             "K3",
					MatchStatus:        StatusUnmatched.Short(),
					MatchReason:        ReasonUnknown.Short(),
					SourceYear:         "0",
				},
			},
		},
		{
			matched: []*BiblioRef{
				&BiblioRef{
					SourceReleaseIdent: "pud5shsflfgrth77lmlernavjm",
					RefIndex:           2,
					RefKey:             "K2",
				},
			},
			refs: []*Ref{
				&Ref{
					ReleaseIdent: "0000",
					Biblio: Biblio{
						Title: "Title",
					},
					Index: 2,
					Key:   "K2",
				},
			},
			result: []*BiblioRef{
				&BiblioRef{
					SourceReleaseIdent: "pud5shsflfgrth77lmlernavjm",
					RefIndex:           2,
					RefKey:             "K2",
				},
			},
		},
	}
	for i, c := range cases {
		result := matchedRefsExtend(c.matched, c.refs, &statsAugment{})
		for _, v := range result {
			v.IndexedTs = "" // we do not want to mock out time, now
		}
		if !reflect.DeepEqual(result, c.result) {
			t.Fatalf("[%d]: got %v, want %v (%v)",
				i+1, result, c.result, pretty.Diff(result, c.result))
		}
	}
}

func TestRemoveSelfLinks(t *testing.T) {
	var cases = []struct {
		brefs  []*BiblioRef
		result []*BiblioRef
	}{
		{
			brefs:  nil,
			result: nil,
		},
		{
			brefs:  []*BiblioRef{},
			result: []*BiblioRef{},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "a"},
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "b"},
			},
			result: []*BiblioRef{
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "b"},
			},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "a"},
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "a"},
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "a"},
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "b"},
			},
			result: []*BiblioRef{
				&BiblioRef{SourceReleaseIdent: "a", TargetReleaseIdent: "b"},
			},
		},
	}
	for i, c := range cases {
		result := removeSelfLinks(c.brefs)
		if !reflect.DeepEqual(result, c.result) {
			t.Fatalf("[%d]: got %v, want %v (%v)",
				i, result, c.result, pretty.Diff(result, c.result))
		}
	}
}

func TestDeduplicateBrefs(t *testing.T) {
	var cases = []struct {
		brefs  []*BiblioRef
		result []*BiblioRef
	}{
		{
			brefs:  nil,
			result: nil,
		},
		{
			brefs:  []*BiblioRef{},
			result: []*BiblioRef{},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
				&BiblioRef{Key: "123", MatchStatus: StatusExact.Short()},
			},
			result: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusExact.Short()},
			},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
				&BiblioRef{Key: "123", MatchStatus: StatusUnmatched.Short()},
			},
			result: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
			},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
				&BiblioRef{Key: "123", MatchStatus: StatusWeak.Short()},
			},
			result: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
			},
		},
		{
			brefs: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
				&BiblioRef{Key: "123", MatchStatus: StatusAmbiguous.Short()},
			},
			result: []*BiblioRef{
				&BiblioRef{Key: "123", MatchStatus: StatusStrong.Short()},
			},
		},
	}
	for i, c := range cases {
		result := deduplicateBrefs(c.brefs)
		if !reflect.DeepEqual(result, c.result) {
			t.Fatalf("[%d]: got %v, want %v (%v)",
				i, result, c.result, pretty.Diff(result, c.result))
		}
	}
}

func TestZippyExact(t *testing.T) {
	var cases = []struct {
		a, b, out string
		err       error
	}{
		{
			a:   "testdata/zippy/cE00a.json",
			b:   "testdata/zippy/cE00b.json",
			out: "testdata/zippy/cE00r.json",
			err: nil,
		},
		{
			a:   "testdata/zippy/cE01a.json",
			b:   "testdata/zippy/cE01b.json",
			out: "testdata/zippy/cE01r.json",
			err: nil,
		},
		{
			a:   "testdata/zippy/cE02a.json",
			b:   "testdata/zippy/cE02b.json",
			out: "testdata/zippy/cE02r.json",
			err: nil,
		},
	}
	timeNow = func() time.Time {
		return time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC)
	}
	for i, c := range cases {
		a, b, err := xio.OpenTwo(c.a, c.b)
		if err != nil {
			t.Errorf("failed to open test files: %v, %v", c.a, c.b)
		}
		var (
			buf         bytes.Buffer
			matchResult = MatchResult{Status: StatusExact, Reason: ReasonDOI}
		)
		err = ZippyExact(a, b, matchResult, &buf)
		if err != c.err {
			t.Errorf("[%d] got %v, want %v", i, err, c.err)
		}
		ok, err := equalsFilename(&buf, c.out)
		if err != nil {
			t.Errorf("failed to open test file: %v", c.out)
		}
		if !ok {
			filename, err := tempWriteFile(&buf)
			if err != nil {
				t.Logf("could not write temp file")
			}
			t.Errorf("[%d] output mismatch (buffer length=%d, content=%v), want %v", i, buf.Len(), filename, c.out)
		}
	}
}

// equalsFilename returns true, if the contents of a given buffer matches the
// contents of a file given by filename.
func equalsFilename(buf *bytes.Buffer, filename string) (bool, error) {
	b, err := ioutil.ReadFile(filename)
	if err != nil {
		return false, err
	}
	bb := buf.Bytes()
	if len(bb) == 0 && len(b) == 0 {
		return true, nil
	}
	return reflect.DeepEqual(b, bb), nil
}

// tempWriteFile writes the content of a buffer to a temporary file and returns
// its path.
func tempWriteFile(buf *bytes.Buffer) (string, error) {
	f, err := ioutil.TempFile("", "skate-test-*")
	if err != nil {
		return "", err
	}
	if err = atomic.WriteFile(f.Name(), buf.Bytes(), 0755); err != nil {
		return "", err
	}
	return f.Name(), nil
}