package handlers_test

import (
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"sneak.berlin/go/webhooker/internal/handlers"
)

// bodyView is how the pages would show body, stored whole.
func bodyView(body string) handlers.BodyView {
	return handlers.NewBodyViewForTest([]byte(body), int64(len(body)))
}

// lines is n lines of text, without a newline after the last.
func lines(n int) string {
	return strings.TrimSuffix(strings.Repeat("line\n", n), "\n")
}

// TestNewBodyView_FormatsValidJSON proves a JSON body is shown
// pretty-printed, whatever its content type, with its keys in
// the order they arrived.
func TestNewBodyView_FormatsValidJSON(t *testing.T) {
	t.Parallel()

	v := bodyView(`{"b":1,"a":[true,null,"x"],"c":{}}`)

	assert.Equal(t, []string{
		`{`,
		`  "b": 1,`,
		`  "a": [`,
		`    true,`,
		`    null,`,
		`    "x"`,
		`  ],`,
		`  "c": {}`,
		`}`,
	}, strings.Split(v.Text, "\n"))
	assert.False(t, v.Scroll)
}

// TestNewBodyView_FormatsNestedJSON proves a document with a few
// levels of nesting is pretty-printed: only deep nesting is shown
// as received.
func TestNewBodyView_FormatsNestedJSON(t *testing.T) {
	t.Parallel()

	v := bodyView(`{"data":[[1,2,3],[4,5,6]]}`)

	assert.Equal(t, []string{
		`{`,
		`  "data": [`,
		`    [`,
		`      1,`,
		`      2,`,
		`      3`,
		`    ],`,
		`    [`,
		`      4,`,
		`      5,`,
		`      6`,
		`    ]`,
		`  ]`,
		`}`,
	}, strings.Split(v.Text, "\n"))
}

// TestNewBodyView_InvalidJSONAsReceived proves a body that is not
// a JSON document is shown exactly as it arrived.
func TestNewBodyView_InvalidJSONAsReceived(t *testing.T) {
	t.Parallel()

	for _, body := range []string{
		`{"a":1,`,
		`{"a":1} {"b":2}`,
		"plain text\n  indented",
	} {
		assert.Equal(t, body, bodyView(body).Text)
	}
}

// TestNewBodyView_DeepJSONAsReceived proves a JSON body nested
// more than 16 levels deep is shown as it arrived. 10 KB of nested
// arrays would indent to some 50 MB.
func TestNewBodyView_DeepJSONAsReceived(t *testing.T) {
	t.Parallel()

	nested := func(depth int) string {
		return strings.Repeat("[", depth) + "1" + strings.Repeat("]", depth)
	}

	assert.NotEqual(t, nested(16), bodyView(nested(16)).Text)
	assert.Equal(t, nested(17), bodyView(nested(17)).Text)

	body := strings.Repeat("[", 5000) + strings.Repeat("]", 5000)

	assert.Equal(t, body, bodyView(body).Text)
}

// TestNewBodyView_ScrollsPast200Lines proves a body is shown at
// its full height up to 200 lines and in the scrolling box past
// them, counting the lines after formatting.
func TestNewBodyView_ScrollsPast200Lines(t *testing.T) {
	t.Parallel()

	assert.False(t, bodyView(lines(200)).Scroll)
	assert.True(t, bodyView(lines(201)).Scroll)

	// A final newline ends the last line rather than starting another.
	assert.False(t, bodyView(lines(200)+"\n").Scroll)
	assert.True(t, bodyView(lines(201)+"\n").Scroll)

	// One line as received, 201 once formatted: the brackets and
	// 199 elements.
	numbers := "[" + strings.TrimSuffix(strings.Repeat("1,", 199), ",") + "]"

	assert.NotContains(t, numbers, "\n")
	assert.True(t, bodyView(numbers).Scroll)
}

// TestNewBodyView_LargeBodyScrolls proves a body larger than the
// cap of the lists of events is shown in the scrolling box
// however few lines it has, on the event's own page as in the
// lists.
func TestNewBodyView_LargeBodyScrolls(t *testing.T) {
	t.Parallel()

	assert.False(t, bodyView(strings.Repeat("x", bodyCap)).Scroll)
	assert.True(t, bodyView(strings.Repeat("x", bodyCap+1)).Scroll)
}

// TestNewBodyView_BinaryNotShown proves a body that is not text
// is never shown: one that is not valid UTF-8, or that holds a
// control character other than tab, line feed and carriage return.
func TestNewBodyView_BinaryNotShown(t *testing.T) {
	t.Parallel()

	for _, body := range []string{
		"\xff\xfe\xfd",
		"a\x00b",
		// A small protobuf message: valid UTF-8, but control bytes.
		"\x08\x01\x12\x03abc",
		"\x1b[31mred\x1b[0m",
		"a\x7fb",
	} {
		v := bodyView(body)

		assert.True(t, v.Binary, "%q", body)
		assert.Empty(t, v.Text)
	}

	assert.False(t, bodyView("snow "+snowman).Binary)
	assert.False(t, bodyView("a\tb\r\nc\n").Binary)
}