package gocsv

import (
	"bytes"
	"encoding/csv"
	"io"
	"math"
	"strconv"
	"strings"
	"testing"
	"time"
)

func assertLine(t *testing.T, expected, actual []string) {
	if len(expected) != len(actual) {
		t.Fatalf("line length mismatch between expected: %d and actual: %d", len(expected), len(actual))
	}
	for i := range expected {
		if expected[i] != actual[i] {
			t.Fatalf("mismatch on field %d at line `%s`: %s != %s", i, expected, expected[i], actual[i])
		}
	}
}

func Test_writeTo(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	blah := 2
	sptr := "*string"
	s := []Sample{
		{Foo: "f", Bar: 1, Baz: "baz", Frop: 0.1, Blah: &blah, SPtr: &sptr},
		{Foo: "e", Bar: 3, Baz: "b", Frop: 6.0 / 13, Blah: nil, SPtr: nil},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), s, false); err != nil {
		t.Fatal(err)
	}

	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 3 {
		t.Fatalf("expected 3 lines, got %d", len(lines))
	}
	assertLine(t, []string{"foo", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit"}, lines[0])
	assertLine(t, []string{"f", "1", "baz", "0.1", "2", "*string", ""}, lines[1])
	assertLine(t, []string{"e", "3", "b", "0.46153846153846156", "", "", ""}, lines[2])
}

func Test_writeTo_Time(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	d := time.Unix(60, 0)
	s := []DateTime{
		{Foo: d},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), s, true); err != nil {
		t.Fatal(err)
	}

	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}

	ft := time.Now()
	ft.UnmarshalText([]byte(lines[0][0]))
	if err != nil {
		t.Fatal(err)
	}
	if ft.Sub(d) != 0 {
		t.Fatalf("Dates doesn't match: %s and actual: %s", d, d)
	}

	m, _ := d.MarshalText()
	assertLine(t, []string{string(m)}, lines[0])
}

func Test_writeTo_NoHeaders(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	blah := 2
	sptr := "*string"
	s := []Sample{
		{Foo: "f", Bar: 1, Baz: "baz", Frop: 0.1, Blah: &blah, SPtr: &sptr},
		{Foo: "e", Bar: 3, Baz: "b", Frop: 6.0 / 13, Blah: nil, SPtr: nil},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), s, true); err != nil {
		t.Fatal(err)
	}

	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 2 {
		t.Fatalf("expected 2 lines, got %d", len(lines))
	}
	assertLine(t, []string{"f", "1", "baz", "0.1", "2", "*string", ""}, lines[0])
	assertLine(t, []string{"e", "3", "b", "0.46153846153846156", "", "", ""}, lines[1])
}

func Test_writeTo_multipleTags(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	s := []MultiTagSample{
		{Foo: "abc", Bar: 123},
		{Foo: "def", Bar: 234},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), s, false); err != nil {
		t.Fatal(err)
	}

	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 3 {
		t.Fatalf("expected 3 lines, got %d", len(lines))
	}
	// the first tag for each field is the encoding CSV header
	assertLine(t, []string{"Baz", "BAR"}, lines[0])
	assertLine(t, []string{"abc", "123"}, lines[1])
	assertLine(t, []string{"def", "234"}, lines[2])
}

func Test_writeTo_embed(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	blah := 2
	sptr := "*string"
	s := []EmbedSample{
		{
			Qux:    "aaa",
			Sample: Sample{Foo: "f", Bar: 1, Baz: "baz", Frop: 0.2, Blah: &blah, SPtr: &sptr},
			Ignore: "shouldn't be marshalled",
			Quux:   "zzz",
			Grault: math.Pi,
		},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), s, false); err != nil {
		t.Fatal(err)
	}

	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 2 {
		t.Fatalf("expected 2 lines, got %d", len(lines))
	}
	assertLine(t, []string{"first", "foo", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit", "garply", "last"}, lines[0])
	assertLine(t, []string{"aaa", "f", "1", "baz", "0.2", "2", "*string", "", "3.141592653589793", "zzz"}, lines[1])
}

func Test_writeTo_complex_embed(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	sptr := "*string"
	sfs := []SkipFieldSample{
		{
			EmbedSample: EmbedSample{
				Qux: "aaa",
				Sample: Sample{
					Foo:  "bbb",
					Bar:  111,
					Baz:  "ddd",
					Frop: 1.2e22,
					Blah: nil,
					SPtr: &sptr,
				},
				Ignore: "eee",
				Grault: 0.1,
				Quux:   "fff",
			},
			MoreIgnore: "ggg",
			Corge:      "hhh",
		},
	}
	if err := writeTo(NewSafeCSVWriter(csv.NewWriter(e.out)), sfs, false); err != nil {
		t.Fatal(err)
	}
	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 2 {
		t.Fatalf("expected 2 lines, got %d", len(lines))
	}
	assertLine(t, []string{"first", "foo", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit", "garply", "last", "abc"}, lines[0])
	assertLine(t, []string{"aaa", "bbb", "111", "ddd", "12000000000000000000000", "", "*string", "", "0.1", "fff", "hhh"}, lines[1])
}

func Test_writeToChan(t *testing.T) {
	b := bytes.Buffer{}
	e := &encoder{out: &b}
	c := make(chan interface{})
	sptr := "*string"
	go func() {
		for i := 0; i < 100; i++ {
			v := Sample{Foo: "f", Bar: i, Baz: "baz" + strconv.Itoa(i), Frop: float64(i), Blah: nil, SPtr: &sptr}
			c <- v
		}
		close(c)
	}()
	if err := MarshalChan(c, NewSafeCSVWriter(csv.NewWriter(e.out))); err != nil {
		t.Fatal(err)
	}
	lines, err := csv.NewReader(&b).ReadAll()
	if err != nil {
		t.Fatal(err)
	}
	if len(lines) != 101 {
		t.Fatalf("expected 100 lines, got %d", len(lines))
	}
	for i, l := range lines {
		if i == 0 {
			assertLine(t, []string{"foo", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit"}, l)
			continue
		}
		assertLine(t, []string{"f", strconv.Itoa(i - 1), "baz" + strconv.Itoa(i-1), strconv.FormatFloat(float64(i-1), 'f', -1, 64), "", "*string", ""}, l)
	}
}

// TestRenamedTypes tests for marshaling functions on redefined basic types.
func TestRenamedTypesMarshal(t *testing.T) {
	samples := []RenamedSample{
		{RenamedFloatUnmarshaler: 1.4, RenamedFloatDefault: 1.5},
		{RenamedFloatUnmarshaler: 2.3, RenamedFloatDefault: 2.4},
	}

	SetCSVWriter(func(out io.Writer) *SafeCSVWriter {
		csvout := NewSafeCSVWriter(csv.NewWriter(out))
		csvout.Comma = ';'
		return csvout
	})
	// Switch back to default for tests executed after this
	defer SetCSVWriter(DefaultCSVWriter)

	csvContent, err := MarshalString(&samples)
	if err != nil {
		t.Fatal(err)
	}
	if csvContent != "foo;bar\n1,4;1.5\n2,3;2.4\n" {
		t.Fatalf("Error marshaling floats with , as separator. Expected \nfoo;bar\n1,4;1.5\n2,3;2.4\ngot:\n%v", csvContent)
	}

	// Test that errors raised by MarshalCSV are correctly reported
	samples = []RenamedSample{
		{RenamedFloatUnmarshaler: 4.2, RenamedFloatDefault: 1.5},
	}
	_, err = MarshalString(&samples)
	if _, ok := err.(MarshalError); !ok {
		t.Fatalf("Expected UnmarshalError, got %v", err)
	}
}

// TestCustomTagSeparatorMarshal tests for custom tag separator in marshalling.
func TestCustomTagSeparatorMarshal(t *testing.T) {
	samples := []RenamedSample{
		{RenamedFloatUnmarshaler: 1.4, RenamedFloatDefault: 1.5},
		{RenamedFloatUnmarshaler: 2.3, RenamedFloatDefault: 2.4},
	}

	TagSeparator = " | "
	// Switch back to default TagSeparator after this
	defer func() {
		TagSeparator = ","
	}()

	csvContent, err := MarshalString(&samples)
	if err != nil {
		t.Fatal(err)
	}
	if csvContent != "foo|bar\n1,4|1.5\n2,3|2.4\n" {
		t.Fatalf("Error marshaling floats with , as separator. Expected \nfoo|bar\n1,4|1.5\n2,3|2.4\ngot:\n%v", csvContent)
	}
}

func (rf *RenamedFloat64Unmarshaler) MarshalCSV() (csv string, err error) {
	if *rf == RenamedFloat64Unmarshaler(4.2) {
		return "", MarshalError{"Test error: Invalid float 4.2"}
	}
	csv = strconv.FormatFloat(float64(*rf), 'f', 1, 64)
	csv = strings.Replace(csv, ".", ",", -1)
	return csv, nil
}

type MarshalError struct {
	msg string
}

func (e MarshalError) Error() string {
	return e.msg
}