import type { Plugin } from "@opencode-ai/plugin"

import { stablePrefixBlock } from "../../packages/prompt-kit/src/index"

const SENSITIVE = /\.(env|aws|ssh|git)(\.|\/|$)/i

const FRAME_RE = /<CONTEXT_FRAME[^>]*>[\s\S]*?<\/CONTEXT_FRAME>/g

export function onPreSendPrompt(input: unknown) {

const text = typeof input === "string" ? input : String(input ?? "")

const p = stablePrefixBlock()

const has = text.includes("## Stable Project Rules") && text.includes("## Coding Standards")

const base = has ? text : `${p.text}\n\n${text}`

const frames = base.match(FRAME_RE) ?? []

const last = frames.length ? frames[frames.length - 1] : ""

const stripped = base.replace(FRAME_RE, "").trim()

const joined = last ? `${last}\n\n${stripped}` : stripped

const frame = FRAME_RE.test(joined)

? joined

: `<!-- WARNING: no CONTEXT_FRAME detected; call repo.workingSet.select and include context_block -->\n${joined}`

const hint = /\[FULL\]/.test(frame) && !/tests?\//i.test(frame)

? `<!-- Hint: prefer readSpan for non-test files -->\n${frame}`

: frame

const warn = SENSITIVE.test(hint)

? `<!-- WARNING: sensitive filename detected; remove from prompt -->\n${hint}`

: hint

return `<!-- prefix_sha256=${p.sha256} -->\n${warn}`

}

export const contextPack: Plugin = async () => ({

async "chat.message"(_input, output) {

output.parts = output.parts.map((part) => {

if (part.type !== "text") return part

if (!part.text) return part

return { ...part, text: onPreSendPrompt(part.text) }

})

},

})