opencode/packages/ui/src/components/markdown-stream.ts

50 lines
1.6 KiB
TypeScript

import { marked, type Tokens } from "marked"
import remend from "remend"
export type Block = {
raw: string
src: string
mode: "full" | "live"
}
function refs(text: string) {
return /^\[[^\]]+\]:\s+\S+/m.test(text) || /^\[\^[^\]]+\]:\s+/m.test(text)
}
function open(raw: string) {
const match = raw.match(/^[ \t]{0,3}(`{3,}|~{3,})/)
if (!match) return false
const mark = match[1]
if (!mark) return false
const char = mark[0]
const size = mark.length
const last = raw.trimEnd().split("\n").at(-1)?.trim() ?? ""
return !new RegExp(`^[\\t ]{0,3}${char}{${size},}[\\t ]*$`).test(last)
}
function heal(text: string) {
return remend(text, { linkMode: "text-only" })
}
export function stream(text: string, live: boolean) {
if (!live) return [{ raw: text, src: text, mode: "full" }] satisfies Block[]
const src = heal(text)
if (refs(text)) return [{ raw: text, src, mode: "live" }] satisfies Block[]
const tokens = marked.lexer(text)
const tail = tokens.findLastIndex((token) => token.type !== "space")
if (tail < 0) return [{ raw: text, src, mode: "live" }] satisfies Block[]
const last = tokens[tail]
if (!last || last.type !== "code") return [{ raw: text, src, mode: "live" }] satisfies Block[]
const code = last as Tokens.Code
if (!open(code.raw)) return [{ raw: text, src, mode: "live" }] satisfies Block[]
const head = tokens
.slice(0, tail)
.map((token) => token.raw)
.join("")
if (!head) return [{ raw: code.raw, src: code.raw, mode: "live" }] satisfies Block[]
return [
{ raw: head, src: heal(head), mode: "live" },
{ raw: code.raw, src: code.raw, mode: "live" },
] satisfies Block[]
}