1 files changed, 102 insertions, 0 deletions
diff --git a/src/util/urls.js b/src/util/urls.js
new file mode 100644
index 0000000..f0f9cdb
--- /dev/null
+++ b/src/util/urls.js
@@ -0,0 +1,102 @@
+// Code that deals with URLs (really the pathnames that get referenced all
+// throughout the gener8ted HTML). Most nota8ly here is generateURLs, which
+// is in charge of pre-gener8ting a complete network of template strings
+// which can really quickly take su8stitute parameters to link from any one
+// place to another; 8ut there are also a few other utilities, too.
+//
+// Nota8ly, everything here is string-8ased, for gener8ting and transforming
+// actual path strings. More a8stract operations using wiki data o8jects is
+// the domain of link.js.
+
+import * as path from 'path';
+import { withEntries } from './sugar.js';
+
+export function generateURLs(urlSpec) {
+    const getValueForFullKey = (obj, fullKey, prop = null) => {
+        const [ groupKey, subKey ] = fullKey.split('.');
+        if (!groupKey || !subKey) {
+            throw new Error(`Expected group key and subkey (got ${fullKey})`);
+        }
+
+        if (!obj.hasOwnProperty(groupKey)) {
+            throw new Error(`Expected valid group key (got ${groupKey})`);
+        }
+
+        const group = obj[groupKey];
+
+        if (!group.hasOwnProperty(subKey)) {
+            throw new Error(`Expected valid subkey (got ${subKey} for group ${groupKey})`);
+        }
+
+        return {
+            value: group[subKey],
+            group
+        };
+    };
+
+    const generateTo = (fromPath, fromGroup) => {
+        const rebasePrefix = '../'.repeat((fromGroup.prefix || '').split('/').filter(Boolean).length);
+
+        const pathHelper = (toPath, toGroup) => {
+            let target = toPath;
+
+            let argIndex = 0;
+            target = target.replaceAll('<>', () => `<${argIndex++}>`);
+
+            if (toGroup.prefix !== fromGroup.prefix) {
+                // TODO: Handle differing domains in prefixes.
+                target = rebasePrefix + (toGroup.prefix || '') + target;
+            }
+
+            return (path.relative(fromPath, target)
+                + (toPath.endsWith('/') ? '/' : ''));
+        };
+
+        const groupSymbol = Symbol();
+
+        const groupHelper = urlGroup => ({
+            [groupSymbol]: urlGroup,
+            ...withEntries(urlGroup.paths, entries => entries
+                .map(([key, path]) => [key, pathHelper(path, urlGroup)]))
+        });
+
+        const relative = withEntries(urlSpec, entries => entries
+            .map(([key, urlGroup]) => [key, groupHelper(urlGroup)]));
+
+        const to = (key, ...args) => {
+            const { value: template, group: {[groupSymbol]: toGroup} } = getValueForFullKey(relative, key)
+            let result = template.replaceAll(/<([0-9]+)>/g, (match, n) => args[n]);
+
+            // Kinda hacky lol, 8ut it works.
+            const missing = result.match(/<([0-9]+)>/g);
+            if (missing) {
+                throw new Error(`Expected ${missing[missing.length - 1]} arguments, got ${args.length}`);
+            }
+
+            return result;
+        };
+
+        return {to, relative};
+    };
+
+    const generateFrom = () => {
+        const map = withEntries(urlSpec, entries => entries
+            .map(([key, group]) => [key, withEntries(group.paths, entries => entries
+                .map(([key, path]) => [key, generateTo(path, group)])
+            )]));
+
+        const from = key => getValueForFullKey(map, key).value;
+
+        return {from, map};
+    };
+
+    return generateFrom();
+}
+
+const thumbnailHelper = name => file =>
+    file.replace(/\.(jpg|png)$/, name + '.jpg');
+
+export const thumb = {
+    medium: thumbnailHelper('.medium'),
+    small: thumbnailHelper('.small')
+};