package render //nolint:testpackage

import (
	"bufio"
	"bytes"
	"context"
	"fmt"
	"path/filepath"
	"reflect"
	"runtime"
	"testing"
	"text/template"

	"github.com/gruntwork-io/boilerplate/options"
	"github.com/gruntwork-io/boilerplate/testutil"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

const windowsOS = "windows"

func TestExtractSnippetName(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		line            string
		snippetName     string
		containsSnippet bool
	}{
		{line: "", containsSnippet: false, snippetName: ""},
		{line: "foo", containsSnippet: false, snippetName: ""},
		{line: "boilerplate", containsSnippet: false, snippetName: ""},
		{line: "boilerplate-snippet", containsSnippet: false, snippetName: ""},
		{line: "boilerplate-snippet:", containsSnippet: false, snippetName: ""},
		{line: "boilerplate-snippet: ", containsSnippet: false, snippetName: ""},
		{line: "boilerplate-snippet: foo", containsSnippet: true, snippetName: "foo"},
		{line: "boilerplate-snippet:foo", containsSnippet: true, snippetName: "foo"},
		{line: "boilerplate-snippet:\t\tfoo        ", containsSnippet: true, snippetName: "foo"},
		{line: "<!-- boilerplate-snippet: foo -->", containsSnippet: true, snippetName: "foo"},
		{line: "// boilerplate-snippet: foo", containsSnippet: true, snippetName: "foo"},
		{line: "/* boilerplate-snippet: foo */", containsSnippet: true, snippetName: "foo"},
		{line: "boilerplate-snippet: foo bar", containsSnippet: true, snippetName: "foo"},
		{line: "boilerplate-snippet:foo-bar-baz", containsSnippet: true, snippetName: "foo-bar-baz"},
	}

	for _, testCase := range testCases {
		snippetName, containsSnippet := extractSnippetName(testCase.line)
		assert.Equal(t, testCase.containsSnippet, containsSnippet)
		assert.Equal(t, testCase.snippetName, snippetName)
	}
}

const multilineSnippetNotTerminated = `
foo
boilerplate-snippet: foo
bar blah
boilerplate-snippet: bar
`

const bodyTextOneLine = "line1"

const bodyTextMultiline = `
line1
line2
line3
`

var fullFileOneLineSnippet = fmt.Sprintf(
	`
boilerplate-snippet: foo
%s
boilerplate-snippet: foo
`, bodyTextOneLine)

var fullFileMultilineSnippet = fmt.Sprintf(
	`
boilerplate-snippet: foo
%s
boilerplate-snippet: foo
`, bodyTextMultiline)

var fullFileMultilineSnippetInHTMLComments = fmt.Sprintf(
	`
<!-- boilerplate-snippet: foo -->
%s
<-- boilerplate-snippet: foo -->
`, bodyTextMultiline)

var partialFileMultilineSnippetInCComments = fmt.Sprintf(
	`
other text
this should be ignored

// boilerplate-snippet: foo
%s
// boilerplate-snippet: foo

this should also
be completely ignored
`, bodyTextMultiline)

var partialFileOneLineSnippetInMismatchedComments = fmt.Sprintf(
	`
other text
this should be ignored

// boilerplate-snippet: foo
%s
/*boilerplate-snippet:foo */

this should also
be completely ignored
`, bodyTextOneLine)

var partialFileMultipleSnippets = fmt.Sprintf(
	`
other text
this should be ignored

boilerplate-snippet: bar
this should be ignored
boilerplate-snippet: bar

boilerplate-snippet: foo
%s
boilerplate-snippet: foo

boilerplate-snippet: baz
this should also
be completely ignored
boilerplate-snippet: baz
`, bodyTextOneLine)

var partialFileEmbeddedSnippets = fmt.Sprintf(
	`
other text
this should be ignored

boilerplate-snippet: bar
bar

boilerplate-snippet: foo
%s
boilerplate-snippet: foo

blah
boilerplate-snippet: bar

boilerplate-snippet: baz
this should also
be completely ignored
boilerplate-snippet: baz
`, bodyTextOneLine)

func TestReadSnippetFromScanner(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		text                string
		snippetName         string
		expectedErr         error
		expectedSnippetText string
	}{
		{text: "", snippetName: "foo", expectedErr: SnippetNotFound("foo"), expectedSnippetText: ""},
		{text: "abcdef", snippetName: "foo", expectedErr: SnippetNotFound("foo"), expectedSnippetText: ""},
		{text: "boilerplate-snippet: bar", snippetName: "foo", expectedErr: SnippetNotFound("foo"), expectedSnippetText: ""},
		{text: "boilerplate-snippet: foo", snippetName: "foo", expectedErr: SnippetNotTerminated("foo"), expectedSnippetText: ""},
		{text: multilineSnippetNotTerminated, snippetName: "foo", expectedErr: SnippetNotTerminated("foo"), expectedSnippetText: ""},
		{text: fullFileOneLineSnippet, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextOneLine},
		{text: fullFileMultilineSnippet, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextMultiline},
		{text: fullFileMultilineSnippetInHTMLComments, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextMultiline},
		{text: partialFileMultilineSnippetInCComments, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextMultiline},
		{text: partialFileOneLineSnippetInMismatchedComments, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextOneLine},
		{text: partialFileMultipleSnippets, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextOneLine},
		{text: partialFileEmbeddedSnippets, snippetName: "foo", expectedErr: nil, expectedSnippetText: bodyTextOneLine},
	}

	for _, testCase := range testCases {
		scanner := bufio.NewScanner(bytes.NewBufferString(testCase.text))
		snippetText, err := readSnippetFromScanner(scanner, testCase.snippetName)

		if testCase.expectedErr == nil {
			require.NoError(t, err)
			assert.Equal(t, testCase.expectedSnippetText, snippetText)
		} else {
			require.Error(t, err)
			require.ErrorIs(t, err, testCase.expectedErr, "Expected %s error but got %s", reflect.TypeOf(testCase.expectedErr), reflect.TypeOf(err))
		}
	}
}

func TestPathRelativeToTemplate(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		templatePath string
		path         string
		expected     string
		skip         bool
	}{
		{"/template.txt", ".", filepath.ToSlash("/"), false},
		{"/foo/bar/template.txt", ".", filepath.ToSlash("/foo/bar"), false},
		{"/foo/bar/template.txt", "..", filepath.ToSlash("/foo"), false},
		{"/foo/bar/template.txt", "../..", filepath.ToSlash("/"), false},
		{"/foo/bar/template.txt", "../../bar/baz", filepath.ToSlash("/bar/baz"), false},
		{"/foo/bar/template.txt", "foo", filepath.ToSlash("/foo/bar/foo"), false},
		{"/foo/bar/template.txt", "./foo", filepath.ToSlash("/foo/bar/foo"), false},
		{"/foo/bar/template.txt", "/foo", filepath.ToSlash("/foo"), false},
		{"/foo/bar/template.txt", "/foo/bar/baz", filepath.ToSlash("/foo/bar/baz"), false},
		{"/usr/bin", "../foo", "/usr/foo", runtime.GOOS == windowsOS}, // Note, we are testing with a real file path here to ensure directories are handled correctly
	}

	for _, testCase := range testCases {
		tt := testCase
		t.Run(tt.templatePath, func(t *testing.T) {
			t.Parallel()

			if tt.skip {
				t.Skip()
				return
			}

			actual := PathRelativeToTemplate(tt.templatePath, tt.path)
			assert.Equal(t, tt.expected, filepath.ToSlash(actual))
		})
	}
}

func TestWrapWithTemplatePath(t *testing.T) {
	t.Parallel()

	expectedPath := "/foo/bar/template.txt"
	expectedOpts := &options.BoilerplateOptions{NonInteractive: true}

	var (
		actualPath string
		actualOpts *options.BoilerplateOptions
	)

	wrappedFunc := wrapWithTemplatePath(
		t.Context(),
		expectedPath,
		expectedOpts,
		func(ctx context.Context, templatePath string, opts *options.BoilerplateOptions, args ...string) (string, error) {
			actualPath = templatePath
			actualOpts = opts

			return templatePath, nil
		})

	returnedPath, err := wrappedFunc()
	require.NoError(t, err)
	assert.Equal(t, expectedPath, returnedPath)
	assert.Equal(t, expectedPath, actualPath)
	assert.Equal(t, expectedOpts, actualOpts)
}

func TestDasherize(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    string
		expected string
	}{
		{"", ""},
		{"     ", ""},
		{"foo", "foo"},
		{"FOO", "foo"},
		{" \t  foo   \t", "foo"},
		{"FooBarBaz", "foo-bar-baz"},
		{"Fo", "fo"},
		{"fooID", "foo-id"},
		{"FoB", "fo-b"},
		{"oFo", "o-fo"},
		{"FoBa", "fo-ba"},
		{"oFoBa", "o-fo-ba"},
		{"oFoB", "o-fo-b"},
		{"Foo123B1234Baz1234", "foo123-b1234-baz1234"},
		{"Foo_Bar_Baz", "foo-bar-baz"},
		{"FooIDbarBaz", "foo-idbar-baz"},
		{"FOOIDbarBaz", "fooidbar-baz"},
		{" A B C ", "a-b-c"},
		{"foo bar baz", "foo-bar-baz"},
		{"foo \t \tbar   baz \t", "foo-bar-baz"},
		{"foo_bar_baz", "foo-bar-baz"},
		{"_foo_bar_baz_", "foo-bar-baz"},
		{"foo-bar-baz", "foo-bar-baz"},
		{"foo--bar----baz", "foo-bar-baz"},
		{"foo__bar____baz", "foo-bar-baz"},
		{" Foo Bar Baz ", "foo-bar-baz"},
		{" Foo Bar_BazBlah ", "foo-bar-baz-blah"},
		{" Foo.Bar.Baz", "foo-bar-baz"},
		{"#@!Foo@#$@$Bar>>>>>Baz", "foo-bar-baz"},
	}

	for _, testCase := range testCases {
		actual := dasherize(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling dasherize on '%s', expected '%s', but got '%s'", testCase.input, testCase.expected, actual)
	}
}

func TestSnakeCase(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    string
		expected string
	}{
		{"", ""},
		{"     ", ""},
		{"foo", "foo"},
		{"FOO", "foo"},
		{" \t  foo   \t", "foo"},
		{"FooBarBaz", "foo_bar_baz"},
		{"Fo", "fo"},
		{"fooID", "foo_id"},
		{"FoB", "fo_b"},
		{"oFo", "o_fo"},
		{"FoBa", "fo_ba"},
		{"oFoBa", "o_fo_ba"},
		{"oFoB", "o_fo_b"},
		{"Foo123B1234Baz1234", "foo123_b1234_baz1234"},
		{"Foo_Bar_Baz", "foo_bar_baz"},
		{"FooIDbarBaz", "foo_idbar_baz"},
		{"FOOIDbarBaz", "fooidbar_baz"},
		{" A B C ", "a_b_c"},
		{"foo bar baz", "foo_bar_baz"},
		{"foo \t \tbar   baz \t", "foo_bar_baz"},
		{"foo_bar_baz", "foo_bar_baz"},
		{"_foo_bar_baz_", "foo_bar_baz"},
		{"foo-bar-baz", "foo_bar_baz"},
		{"foo--bar----baz", "foo_bar_baz"},
		{"foo__bar____baz", "foo_bar_baz"},
		{" Foo Bar Baz ", "foo_bar_baz"},
		{" Foo Bar_BazBlah ", "foo_bar_baz_blah"},
		{" Foo.Bar.Baz", "foo_bar_baz"},
		{"#@!Foo@#$@$Bar>>>>>Baz", "foo_bar_baz"},
	}

	for _, testCase := range testCases {
		actual := snakeCase(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling snakeCase on '%s', expected '%s', but got '%s'", testCase.input, testCase.expected, actual)
	}
}

func TestCamelCase(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    string
		expected string
	}{
		{"", ""},
		{"     ", ""},
		{"foo", "Foo"},
		{"FOO", "FOO"},
		{" \t  foo   \t", "Foo"},
		{"FooBarBaz", "FooBarBaz"},
		{"Fo", "Fo"},
		{"fooID", "FooID"},
		{"FoB", "FoB"},
		{"oFo", "OFo"},
		{"FoBa", "FoBa"},
		{"oFoBa", "OFoBa"},
		{"oFoB", "OFoB"},
		{"Foo123B1234Baz1234", "Foo123B1234Baz1234"},
		{"Foo_Bar_Baz", "FooBarBaz"},
		{"FooIDbarBaz", "FooIDbarBaz"},
		{"FOOIDbarBaz", "FOOIDbarBaz"},
		{" A B C ", "ABC"},
		{"foo bar baz", "FooBarBaz"},
		{"foo \t \tbar   baz \t", "FooBarBaz"},
		{"foo_bar_baz", "FooBarBaz"},
		{"_foo_bar_baz_", "FooBarBaz"},
		{"foo-bar-baz", "FooBarBaz"},
		{"foo--bar----baz", "FooBarBaz"},
		{"foo__bar____baz", "FooBarBaz"},
		{" Foo Bar Baz ", "FooBarBaz"},
		{" Foo Bar_BazBlah ", "FooBarBazBlah"},
		{" Foo.Bar.Baz", "FooBarBaz"},
		{"#@!Foo@#$@$Bar>>>>>Baz", "FooBarBaz"},
	}

	for _, testCase := range testCases {
		actual := camelCase(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling camelCase on '%s', expected '%s', but got '%s'", testCase.input, testCase.expected, actual)
	}
}

func TestCamelCaseLower(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    string
		expected string
	}{
		{"", ""},
		{"     ", ""},
		{"foo", "foo"},
		{"FOO", "fOO"},
		{" \t  foo   \t", "foo"},
		{"FooBarBaz", "fooBarBaz"},
		{"Fo", "fo"},
		{"fooID", "fooID"},
		{"FoB", "foB"},
		{"oFo", "oFo"},
		{"FoBa", "foBa"},
		{"oFoBa", "oFoBa"},
		{"oFoB", "oFoB"},
		{"Foo123B1234Baz1234", "foo123B1234Baz1234"},
		{"Foo_Bar_Baz", "fooBarBaz"},
		{"FooIDbarBaz", "fooIDbarBaz"},
		{"FOOIDbarBaz", "fOOIDbarBaz"},
		{" A B C ", "aBC"},
		{"foo bar baz", "fooBarBaz"},
		{"foo \t \tbar   baz \t", "fooBarBaz"},
		{"foo_bar_baz", "fooBarBaz"},
		{"_foo_bar_baz_", "fooBarBaz"},
		{"foo-bar-baz", "fooBarBaz"},
		{"foo--bar----baz", "fooBarBaz"},
		{"foo__bar____baz", "fooBarBaz"},
		{" Foo Bar Baz ", "fooBarBaz"},
		{" Foo Bar_BazBlah ", "fooBarBazBlah"},
		{" Foo.Bar.Baz", "fooBarBaz"},
		{"#@!Foo@#$@$Bar>>>>>Baz", "fooBarBaz"},
	}

	for _, testCase := range testCases {
		actual := camelCaseLower(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling camelCaseLower on '%s', expected '%s', but got '%s'", testCase.input, testCase.expected, actual)
	}
}

func TestLowerFirst(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    string
		expected string
	}{
		{"", ""},
		{"     ", "     "},
		{"foo", "foo"},
		{"Foo", "foo"},
		{"FOO", "fOO"},
		{"Здравейте", "здравейте"},
	}

	for _, testCase := range testCases {
		actual := lowerFirst(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling lowerFirst on '%s', expected '%s', but got '%s'", testCase.input, testCase.expected, actual)
	}
}

func TestShellSuccess(t *testing.T) {
	t.Parallel()

	var (
		output string
		err    error
		eol    string
	)

	opts := testutil.CreateTestOptionsForShell(true, false)

	if runtime.GOOS == windowsOS {
		eol = "\r\n"
		output, err = shell(t.Context(), ".", opts, "cmd.exe", "/C", "echo", "hi")
	} else {
		eol = "\n"
		output, err = shell(t.Context(), ".", opts, "echo", "hi")
	}

	require.NoError(t, err, "Unexpected error: %v", err)
	assert.Equal(t, "hi"+eol, output)
}

func TestShellError(t *testing.T) {
	t.Parallel()

	opts := testutil.CreateTestOptionsForShell(true, false)

	_, err := shell(t.Context(), ".", opts, "not-a-real-command")
	if assert.Error(t, err) {
		if runtime.GOOS == windowsOS {
			assert.Contains(t, err.Error(), "executable file not found in %PATH%", "Unexpected error message: %s", err.Error())
		} else {
			assert.Contains(t, err.Error(), "executable file not found in $PATH", "Unexpected error message: %s", err.Error())
		}
	}
}

func TestShellDisabled(t *testing.T) {
	t.Parallel()

	opts := testutil.CreateTestOptionsForShell(true, true)
	output, err := shell(t.Context(), ".", opts, "echo", "hi")
	require.NoError(t, err, "Unexpected error: %v", err)
	assert.Equal(t, shellDisabledPlaceholder, output)
}

// TestTemplateIsDefined tests that the templateIsDefined function correctly
// identifies templates that have been added to the parse tree
func TestTemplateIsDefined(t *testing.T) {
	t.Parallel()

	fooTemplate := "This is foo."
	tmplFoo, err := template.New("foo").Parse(fooTemplate)
	require.NoError(t, err)

	f := wrapIsDefinedWithTemplate(tmplFoo)

	assert.True(t, f("foo"))
	assert.False(t, f("bar"))

	barTemplate := "This is bar."
	tmplBar, err := template.New("bar").Parse(barTemplate)
	require.NoError(t, err)

	tmplFoo.AddParseTree("bar", tmplBar.Tree)

	assert.True(t, f("bar"))
}

// TestToYaml tests that a given value can be correctly encoded to YAML
func TestToYaml(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    any
		expected string
	}{
		{nil, "null\n"},
		{"", "\"\"\n"},
		{map[string]any{"key": "val"}, "key: val\n"},
		{map[string][]any{"Key": {1, 2, 3}}, "Key:\n    - 1\n    - 2\n    - 3\n"},
	}
	for _, testCase := range testCases {
		actual, err := toYaml(testCase.input)
		require.NoError(t, err)
		assert.Equal(t, testCase.expected, actual)
	}
}

func TestFromYaml(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		expected any
		name     string
		input    string
	}{
		{
			name:     "empty string",
			input:    "",
			expected: nil,
		},
		{
			name:     "simple scalar values",
			input:    "hello",
			expected: "hello",
		},
		{
			name:     "simple key-value with multiple types",
			input:    "name: John\nage: 30\nactive: true\nheight: 5.9",
			expected: map[string]any{"name": "John", "age": 30, "active": true, "height": 5.9},
		},
		{
			name:     "array",
			input:    "- apple\n- banana\n- 42\n- true",
			expected: []any{"apple", "banana", 42, true},
		},
		{
			name:  "nested object",
			input: "person:\n  name: John\n  age: 30\n  skills:\n    - go\n    - yaml",
			expected: map[string]any{
				"person": map[string]any{
					"name":   "John",
					"age":    30,
					"skills": []any{"go", "yaml"},
				},
			},
		},
		{
			name: "complex structure",
			input: `
config:
  debug: true
  timeout: 300
users:
  - name: Alice
    roles: [admin, user]
  - name: Bob
    roles: [user]`,
			expected: map[string]any{
				"config": map[string]any{
					"debug":   true,
					"timeout": 300,
				},
				"users": []any{
					map[string]any{
						"name":  "Alice",
						"roles": []any{"admin", "user"},
					},
					map[string]any{
						"name":  "Bob",
						"roles": []any{"user"},
					},
				},
			},
		},
		{
			name:     "special cases",
			input:    "message: \"Hello World\"\nnumeric_key: 123\nempty_obj: {}\nempty_array: []",
			expected: map[string]any{"message": "Hello World", "numeric_key": 123, "empty_obj": map[string]any{}, "empty_array": []any{}},
		},
	}

	for _, testCase := range testCases {
		t.Run(testCase.name, func(t *testing.T) {
			t.Parallel()

			actual, err := fromYaml(testCase.input)
			require.NoError(t, err)
			assert.Equal(t, testCase.expected, actual)
		})
	}

	// Test error cases
	t.Run("invalid YAML", func(t *testing.T) {
		invalidCases := []string{
			"invalid: [unclosed",
			"key1: value1\nkey2: [\n  unclosed array",
			"parent:\n\tchild: value\n  other: value", // mixed tab/space indentation
		}

		for _, input := range invalidCases {
			_, err := fromYaml(input)
			assert.Error(t, err, "Expected error for invalid YAML: %s", input)
		}
	})
}

// I cannot believe I have to write my own function and test code for rounding numbers in Go. FML.
func TestRound(t *testing.T) {
	t.Parallel()

	testCases := []struct {
		input    float64
		expected int
	}{
		{0, 0},
		{0.0, 0},
		{0.25, 0},
		{0.49, 0},
		{0.4999999999999, 0},
		{0.5, 1},
		{0.50000000000000001, 1},
		{0.75, 1},
		{0.999999999999999, 1},
		{1, 1},
		{1.0, 1},
		{151515151.234234234, 151515151},
	}

	for _, testCase := range testCases {
		actual := round(testCase.input)
		assert.Equal(t, testCase.expected, actual, "When calling round on %f, expected %d, but got %d", testCase.input, testCase.expected, actual)
	}
}
