| 1 | /** |
| 2 | * Every page's <title> and the tags a link preview reads: its description, |
| 3 | * Open Graph and Twitter's card. The image is the page's own card from the |
| 4 | * og service (services/og), which draws it as an anonymous visitor would |
| 5 | * see the page, so a private page's card never names anything. A g1t without |
| 6 | * the og service (`OG_URL` set empty) leaves the image tags out. |
| 7 | * |
| 8 | * React Router renders only the deepest route's `meta`, so each route |
| 9 | * returns `page(args, …)` rather than a bare title. |
| 10 | */ |
| 11 | import type { MetaDescriptor } from "react-router"; |
| 12 | import { ogVersion } from "@g1t/contracts/og"; |
| 13 | |
| 14 | import type { Addresses } from "./addresses"; |
| 15 | |
| 16 | /** |
| 17 | * g1t.sh's site and card service, the same as HOSTED_ADDRESSES in |
| 18 | * ./addresses (kept here so this module has no imports to run in tests). |
| 19 | * Pages use the addresses in the root loader's data when it has them. |
| 20 | */ |
| 21 | export const SITE = "https://g1t.sh"; |
| 22 | export const OG = "https://og.g1t.sh"; |
| 23 | |
| 24 | /** What g1t is, for pages with nothing more particular to say. */ |
| 25 | export const DESCRIPTION = |
| 26 | "Repositories, pull requests, required checks, a merge queue and deployments, with chat for your team. Connect the coding agents you already use through MCP and the API. Open source, never per seat."; |
| 27 | |
| 28 | /** As much of `MetaArgs` as the tags need. */ |
| 29 | export type PageArgs = { |
| 30 | location: { pathname: string }; |
| 31 | matches: ReadonlyArray<{ id: string; loaderData?: unknown } | undefined>; |
| 32 | }; |
| 33 | |
| 34 | export type PageMeta = { |
| 35 | /** The whole <title>, ending in "· g1t". */ |
| 36 | title: string; |
| 37 | /** Defaults to the project's or workspace's description, then g1t's. */ |
| 38 | description?: string | null; |
| 39 | /** |
| 40 | * Whatever the page's card shows, so that the card is drawn again when it |
| 41 | * changes. Defaults to the project's details on project pages. |
| 42 | */ |
| 43 | version?: unknown; |
| 44 | type?: "website" | "article"; |
| 45 | /** Stable public landing pages may opt into a self-referencing canonical. */ |
| 46 | canonical?: boolean; |
| 47 | }; |
| 48 | |
| 49 | type ProjectData = { |
| 50 | /** Only projects have descriptions; a repository has none. */ |
| 51 | project?: { name?: string; description?: string | null } | null; |
| 52 | open?: { issues?: number; pulls?: number }; |
| 53 | }; |
| 54 | type WorkspaceData = { workspace?: { name?: string; description?: string | null; avatar?: string | null } }; |
| 55 | |
| 56 | function loaded<T>(args: PageArgs, id: string): T | undefined { |
| 57 | return args.matches.find((match) => match?.id === id)?.loaderData as T | undefined; |
| 58 | } |
| 59 | |
| 60 | /** A short, stable fingerprint, for the card's `v`. */ |
| 61 | export function fingerprint(value: unknown): string { |
| 62 | const text = JSON.stringify(value) ?? ""; |
| 63 | // FNV-1a, 32 bits. |
| 64 | let hash = 0x811c9dc5; |
| 65 | for (let i = 0; i < text.length; i++) { |
| 66 | hash ^= text.charCodeAt(i); |
| 67 | hash = Math.imul(hash, 0x01000193); |
| 68 | } |
| 69 | return (hash >>> 0).toString(36); |
| 70 | } |
| 71 | |
| 72 | /** A description fit for a preview: one line, at most 200 characters. */ |
| 73 | function summary(text: string): string { |
| 74 | const line = text.replace(/\s+/g, " ").trim(); |
| 75 | return line.length > 200 ? `${line.slice(0, 199).trimEnd()}…` : line; |
| 76 | } |
| 77 | |
| 78 | /** The opening of some Markdown as plain text, for a description. */ |
| 79 | export function excerpt(markdown: string | null | undefined, max = 160): string { |
| 80 | const text = (markdown ?? "") |
| 81 | .replace(/```[\s\S]*?(```|$)/g, " ") |
| 82 | .replace(/<[^>]+>/g, " ") |
| 83 | .replace(/!\[[^\]]*\]\([^)]*\)/g, " ") |
| 84 | .replace(/\[([^\]]*)\]\([^)]*\)/g, "$1") |
| 85 | .replace(/^\s{0,3}(#{1,6}|>|[-*+]|\d+\.)\s+/gm, "") |
| 86 | .replace(/[`*_~|]/g, "") |
| 87 | .replace(/\s+/g, " ") |
| 88 | .trim(); |
| 89 | return text.length > max ? `${text.slice(0, max - 1).trimEnd()}…` : text; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * The address of a page's card. Its `v` always carries the cards' render |
| 94 | * version, so a new card design is a new address for og's cache, browsers |
| 95 | * and every site that has fetched the old card; then, when the page has one, |
| 96 | * a fingerprint of what the card shows. |
| 97 | */ |
| 98 | export function cardUrl(pathname: string, version?: unknown, og: string = OG): string { |
| 99 | const url = new URL("/image", og); |
| 100 | url.searchParams.set("path", pathname); |
| 101 | url.searchParams.set("v", ogVersion(version === undefined ? undefined : fingerprint(version))); |
| 102 | return url.toString(); |
| 103 | } |
| 104 | |
| 105 | export function page(args: PageArgs, meta: PageMeta): MetaDescriptor[] { |
| 106 | const project = loaded<ProjectData>(args, "routes/repo/layout"); |
| 107 | const workspace = loaded<WorkspaceData>(args, "routes/workspace/layout"); |
| 108 | const description = summary( |
| 109 | meta.description || |
| 110 | project?.project?.description || |
| 111 | workspace?.workspace?.description || |
| 112 | DESCRIPTION, |
| 113 | ); |
| 114 | const version = |
| 115 | meta.version ?? |
| 116 | (project |
| 117 | ? [project.project?.name, project.project?.description ?? null, project.open] |
| 118 | : workspace |
| 119 | ? [ |
| 120 | workspace.workspace?.name, |
| 121 | workspace.workspace?.description, |
| 122 | // Only when there is one, so cards without an icon keep their address. |
| 123 | ...(workspace.workspace?.avatar ? [workspace.workspace.avatar] : []), |
| 124 | ] |
| 125 | : undefined); |
| 126 | const pathname = args.location.pathname.replace(/\/+$/, "") || "/"; |
| 127 | // The title a preview shows needs no "· g1t": the site name is beside it. |
| 128 | const shareTitle = meta.title.replace(/ · g1t$/, ""); |
| 129 | const addresses = loaded<{ addresses?: Pick<Addresses, "site" | "og"> }>(args, "root")?.addresses; |
| 130 | const site = addresses?.site ?? SITE; |
| 131 | const og = addresses ? addresses.og : OG; |
| 132 | const image = og ? cardUrl(pathname, version, og) : null; |
| 133 | return [ |
| 134 | { title: meta.title }, |
| 135 | ...(pathname === "/" || meta.canonical ? [{ tagName: "link" as const, rel: "canonical", href: `${site}${pathname}` }] : []), |
| 136 | { name: "description", content: description }, |
| 137 | { property: "og:site_name", content: "g1t" }, |
| 138 | { property: "og:type", content: meta.type ?? "website" }, |
| 139 | { property: "og:url", content: `${site}${pathname === "/" ? "/" : pathname}` }, |
| 140 | { property: "og:title", content: shareTitle }, |
| 141 | { property: "og:description", content: description }, |
| 142 | ...(image |
| 143 | ? [ |
| 144 | { property: "og:image", content: image }, |
| 145 | { property: "og:image:type", content: "image/png" }, |
| 146 | { property: "og:image:width", content: "1200" }, |
| 147 | { property: "og:image:height", content: "630" }, |
| 148 | { property: "og:image:alt", content: shareTitle }, |
| 149 | ] |
| 150 | : []), |
| 151 | { name: "twitter:card", content: image ? "summary_large_image" : "summary" }, |
| 152 | { name: "twitter:title", content: shareTitle }, |
| 153 | { name: "twitter:description", content: description }, |
| 154 | ...(image |
| 155 | ? [ |
| 156 | { name: "twitter:image", content: image }, |
| 157 | { name: "twitter:image:alt", content: shareTitle }, |
| 158 | ] |
| 159 | : []), |
| 160 | ]; |
| 161 | } |