package main

import (
	"testing"

	"github.com/stretchr/testify/require"
)

func TestMarkdownEntities(t *testing.T) {
	testCases := []struct {
		name     string
		markdown string
		text     string
		entities []TelegramEntity
	}{
		{
			name:     "double asterisks give bold",
			markdown: "a **b** c",
			text:     "a b c",
			entities: []TelegramEntity{
				{
					Type:   "bold",
					Offset: 2,
					Length: 1,
				},
			},
		},
		{
			name:     "double underscores give bold",
			markdown: "__bold__",
			text:     "bold",
			entities: []TelegramEntity{
				{
					Type:   "bold",
					Offset: 0,
					Length: 4,
				},
			},
		},
		{
			name:     "single asterisk gives italic",
			markdown: "an *odd* word",
			text:     "an odd word",
			entities: []TelegramEntity{
				{
					Type:   "italic",
					Offset: 3,
					Length: 3,
				},
			},
		},
		{
			name:     "single underscore gives italic",
			markdown: "an _odd_ word",
			text:     "an odd word",
			entities: []TelegramEntity{
				{
					Type:   "italic",
					Offset: 3,
					Length: 3,
				},
			},
		},
		{
			name:     "double tildes give strikethrough",
			markdown: "~~old~~ new",
			text:     "old new",
			entities: []TelegramEntity{
				{
					Type:   "strikethrough",
					Offset: 0,
					Length: 3,
				},
			},
		},
		{
			name:     "backticks give inline code with no entity inside",
			markdown: "run `go **test**` now",
			text:     "run go **test** now",
			entities: []TelegramEntity{
				{
					Type:   "code",
					Offset: 4,
					Length: 11,
				},
			},
		},
		{
			name:     "double backticks hold a backtick",
			markdown: "``a ` b``",
			text:     "a ` b",
			entities: []TelegramEntity{
				{
					Type:   "code",
					Offset: 0,
					Length: 5,
				},
			},
		},
		{
			name:     "link gives a text link",
			markdown: "see [the docs](https://example.com/a_b) here",
			text:     "see the docs here",
			entities: []TelegramEntity{
				{
					Type:   "text_link",
					Offset: 4,
					Length: 8,
					URL:    "https://example.com/a_b",
				},
			},
		},
		{
			name:     "bold inside a link nests",
			markdown: "[a **b** c](https://example.com)",
			text:     "a b c",
			entities: []TelegramEntity{
				{
					Type:   "text_link",
					Offset: 0,
					Length: 5,
					URL:    "https://example.com",
				},
				{
					Type:   "bold",
					Offset: 2,
					Length: 1,
				},
			},
		},
		{
			name:     "code block with a language gives pre with the language",
			markdown: "Commit:\n```text\nFix the **bug**\n\nBody\n```\nDone.",
			text:     "Commit:\nFix the **bug**\n\nBody\nDone.",
			entities: []TelegramEntity{
				{
					Type:     "pre",
					Offset:   8,
					Length:   21,
					Language: "text",
				},
			},
		},
		{
			name:     "code block without a language gives pre",
			markdown: "```\nls -l\n```",
			text:     "ls -l",
			entities: []TelegramEntity{
				{
					Type:   "pre",
					Offset: 0,
					Length: 5,
				},
			},
		},
		{
			name:     "heading becomes bold with its inline marks",
			markdown: "## The `plan`\nnext",
			text:     "The plan\nnext",
			entities: []TelegramEntity{
				{
					Type:   "bold",
					Offset: 0,
					Length: 8,
				},
				{
					Type:   "code",
					Offset: 4,
					Length: 4,
				},
			},
		},
		{
			name:     "list, quote and table stay as text",
			markdown: "- one\n* two\n1. three\n> quote\n| a | b |\n|---|---|",
			text:     "- one\n* two\n1. three\n> quote\n| a | b |\n|---|---|",
		},
		{
			name:     "asterisk of a list item with italic later stays",
			markdown: "* item with *stress*",
			text:     "* item with stress",
			entities: []TelegramEntity{
				{
					Type:   "italic",
					Offset: 12,
					Length: 6,
				},
			},
		},
		{
			name:     "unclosed marks stay as text",
			markdown: "**open, `tick, [link](, ~~gone and *star",
			text:     "**open, `tick, [link](, ~~gone and *star",
		},
		{
			name:     "unclosed code fence stays as text",
			markdown: "```go\nfmt.Println()",
			text:     "```go\nfmt.Println()",
		},
		{
			name:     "snake case words stay as text",
			markdown: "set snake_case_words and max_tokens_count",
			text:     "set snake_case_words and max_tokens_count",
		},
		{
			name:     "multiplication stays as text",
			markdown: "2 * 3 * 4",
			text:     "2 * 3 * 4",
		},
		{
			name:     "mark does not cross a line break",
			markdown: "**a\nb**",
			text:     "**a\nb**",
		},
		{
			name:     "backslash makes a mark plain",
			markdown: `\*not italic\* and C:\Users`,
			text:     `*not italic* and C:\Users`,
		},
		{
			name:     "character outside the BMP moves the offset by two",
			markdown: "\U0001F600 **b**",
			text:     "\U0001F600 b",
			entities: []TelegramEntity{
				{
					Type:   "bold",
					Offset: 3,
					Length: 1,
				},
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			text, entities := telegramMarkdownEntities(tc.markdown)
			require.Equal(t, tc.text, text)
			require.Equal(t, tc.entities, entities)
		})
	}
}