1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108

// SPDX-FileCopyrightText: 2024 Shota FUJI <pockawoooh@gmail.com>
//
// SPDX-License-Identifier: Apache-2.0

/** @jsx h */

import type * as Hast from "../../../deps/esm.sh/hast/types.ts";
import type * as Mdast from "../../../deps/esm.sh/mdast/types.ts";
import { h } from "../../../deps/esm.sh/hastscript/mod.ts";
import {
	type Handlers,
	type State,
} from "../../../deps/esm.sh/mdast-util-to-hast/mod.ts";

import { type OfmWikilink } from "../../../content_parser/obsidian_markdown/mdast_util_ofm_wikilink.ts";

import { buildClasses, css, join } from "../css.ts";
import * as lucide from "../icons/lucide.tsx";

function isExternal(urlOrPath: string): boolean {
	try {
		new URL(urlOrPath);
		return true;
	} catch {
		return false;
	}
}

const c = buildClasses("fm-li", ["anchor", "externalIcon"]);

export const linkStyles = join(
	lucide.lucideIconStyles,
	css`
		.${c.anchor} {
			font-weight: 500;

			color: var(--color-fg-sub);
			text-decoration: underline;

			transition: color 0.15s ease;
		}

		.${c.anchor}:hover {
			color: var(--color-primary);
		}

		.${c.externalIcon} {
			margin-inline-start: 0.25em;
		}
	`,
);

interface LinkHandlersOptions {
	/**
	 * Whether to set `target="_blank"` to anchor links pointing to
	 * external location.
	 */
	openExternalLinkInBlank?: boolean;
}

function link(
	urlOrPath: string,
	children: Hast.ElementContent[],
	{ openExternalLinkInBlank }: LinkHandlersOptions,
) {
	if (!isExternal(urlOrPath)) {
		return h("a", {
			class: c.anchor,
			href: urlOrPath,
		}, children);
	}

	return h("a", {
		class: c.anchor,
		href: urlOrPath,
		target: openExternalLinkInBlank ? "_blank" : undefined,
		rel: openExternalLinkInBlank ? "noopener" : undefined,
	}, [
		<span>{children}</span>,
		lucide.externalLink({ className: c.externalIcon, "aria-hidden": "true" }),
	]);
}

export function linkHandlers(
	{ openExternalLinkInBlank = true }: LinkHandlersOptions = {},
): Handlers {
	return {
		link(state, node: Mdast.Link) {
			return link(node.url, state.all(node), { openExternalLinkInBlank });
		},
		linkReference(state, node: Mdast.LinkReference) {
			const def = state.definitionById.get(node.identifier);
			if (!def) {
				throw new Error(`Orphaned link reference: id=${node.identifier}`);
			}

			return link(def.url, state.all(node), { openExternalLinkInBlank });
		},
		// @ts-expect-error: unist-related libraries heavily relies on ambient module declarations,
		//                   which Deno does not support. APIs also don't accept type parameters.
		ofmWikilink(_state: State, node: OfmWikilink) {
			return link(node.target, [{
				type: "text",
				value: node.label ?? node.target,
			}], { openExternalLinkInBlank });
		},
	};
}