import { describe, expect, test } from "bun:test"
import fs from "fs/promises"
import path from "path"

import { Process } from "@/util/process"
import { Filesystem } from "@/util/filesystem"
import { tmpdir } from "../fixture/fixture"

const root = path.join(import.meta.dir, "../..")
const worker = path.join(import.meta.dir, "../fixture/plug-worker.ts")

type Msg = {
  dir: string
  target: string
  mod: string
  holdMs?: number
}

function run(msg: Msg) {
  return Process.run([process.execPath, worker, JSON.stringify(msg)], {
    cwd: root,
    nothrow: true,
  })
}

async function plugin(dir: string, kinds: Array<"server" | "tui">) {
  const p = path.join(dir, "plugin")
  const server = kinds.includes("server")
  const tui = kinds.includes("tui")
  const exports: Record<string, string> = {}
  if (server) exports["./server"] = "./server.js"
  if (tui) exports["./tui"] = "./tui.js"
  await fs.mkdir(p, { recursive: true })
  await Bun.write(
    path.join(p, "package.json"),
    JSON.stringify(
      {
        name: "acme",
        version: "1.0.0",
        ...(server ? { main: "./server.js" } : {}),
        ...(Object.keys(exports).length ? { exports } : {}),
      },
      null,
      2,
    ),
  )
  return p
}

async function read(file: string) {
  return Filesystem.readJson<{ plugin?: unknown[] }>(file)
}

function mods(prefix: string, n: number) {
  return Array.from({ length: n }, (_, i) => `${prefix}-${i}@1.0.0`)
}

function expectPlugins(list: unknown[] | undefined, expectMods: string[]) {
  expect(Array.isArray(list)).toBe(true)
  const hit = (list ?? []).filter((item): item is string => typeof item === "string")
  expect(hit.length).toBe(expectMods.length)
  expect(new Set(hit)).toEqual(new Set(expectMods))
}

describe("plugin.install.concurrent", () => {
  test("serializes concurrent server config updates across processes", async () => {
    await using tmp = await tmpdir()
    const target = await plugin(tmp.path, ["server"])
    const all = mods("mod-server", 6)

    const out = await Promise.all(
      all.map((mod) =>
        run({
          dir: tmp.path,
          target,
          mod,
          holdMs: 30,
        }),
      ),
    )

    expect(out.map((x) => x.code)).toEqual(Array.from({ length: all.length }, () => 0))
    expect(out.map((x) => x.stderr.toString()).filter(Boolean)).toEqual([])

    const cfg = await read(path.join(tmp.path, ".Codilore", "Codilore.jsonc"))
    expectPlugins(cfg.plugin, all)
  }, 25_000)

  test("serializes concurrent server+tui config updates across processes", async () => {
    await using tmp = await tmpdir()
    const target = await plugin(tmp.path, ["server", "tui"])
    const all = mods("mod-both", 6)

    const out = await Promise.all(
      all.map((mod) =>
        run({
          dir: tmp.path,
          target,
          mod,
          holdMs: 30,
        }),
      ),
    )

    expect(out.map((x) => x.code)).toEqual(Array.from({ length: all.length }, () => 0))
    expect(out.map((x) => x.stderr.toString()).filter(Boolean)).toEqual([])

    const server = await read(path.join(tmp.path, ".Codilore", "Codilore.jsonc"))
    const tui = await read(path.join(tmp.path, ".Codilore", "tui.jsonc"))
    expectPlugins(server.plugin, all)
    expectPlugins(tui.plugin, all)
  }, 25_000)

  test("preserves updates when existing config uses .json", async () => {
    await using tmp = await tmpdir()
    const target = await plugin(tmp.path, ["server"])
    const cfg = path.join(tmp.path, ".Codilore", "Codilore.json")
    await fs.mkdir(path.dirname(cfg), { recursive: true })
    await Bun.write(cfg, JSON.stringify({ plugin: ["seed@1.0.0"] }, null, 2))

    const next = mods("mod-json", 5)
    const out = await Promise.all(
      next.map((mod) =>
        run({
          dir: tmp.path,
          target,
          mod,
          holdMs: 30,
        }),
      ),
    )

    expect(out.map((x) => x.code)).toEqual(Array.from({ length: next.length }, () => 0))
    expect(out.map((x) => x.stderr.toString()).filter(Boolean)).toEqual([])

    const json = await read(cfg)
    expectPlugins(json.plugin, ["seed@1.0.0", ...next])
    expect(await Filesystem.exists(path.join(tmp.path, ".Codilore", "Codilore.jsonc"))).toBe(false)
  }, 25_000)
})
