import { existsSync, readFileSync } from "node:fs"
import path from "node:path"
import { Plugin, Skill } from "@opencode/plugin"
import { blockedPattern, guardrailError, isShellTool, resolveOptions } from "./guardrails.ts"
import { parseFrontmatter } from "./frontmatter.ts"
import { loadManifest, packageRoot, packageVersion, skillFile } from "./manifest.ts"

const AGENT_IDS = ["pocock", "pocock-worker", "pocock-reviewer"] as const

function installedAgentVersion(projectDir: string): string | undefined {
  const file = path.join(projectDir, ".opencode", "agents", ".pocock-version")
  if (!existsSync(file)) return undefined
  return readFileSync(file, "utf8").trim()
}

export default Plugin.define({
  id: "haylan.pocock",
  async setup(ctx) {
    // Fails loudly on bad options or a broken install instead of silently shipping no skills.
    const options = resolveOptions(ctx.options)
    const entries = loadManifest()

    await ctx.skill.transform((editor) => {
      for (const entry of entries) {
        const file = skillFile(entry)
        // File-based skill loading strips frontmatter from content (core skill.ts uses
        // markdown.content); match that so injected skills read identically.
        const content = parseFrontmatter(readFileSync(file, "utf8")).body.trim()
        // Brand types (Skill.ID/Name/AbsolutePath) are nominal-only; runtime values are plain
        // strings, asserted by test/plugin.test.ts and the serve-based smoke run.
        editor.add({
          id: entry.id,
          name: entry.name,
          description: entry.description,
          autoinvoke: entry.autoinvoke,
          path: file,
          content,
        } as unknown as Skill.Info)
      }
    })

    if (options.guardrails) {
      await ctx.tool.hook("execute.before", (event) => {
        if (!isShellTool(event.tool)) return
        const command = (event.input as { command?: unknown } | undefined)?.command
        if (typeof command !== "string") return
        const pattern = blockedPattern(command)
        if (pattern) throw new Error(`pocock guardrails: ${guardrailError(command, pattern)}`)
      })
    }

    // Agents cannot be registered by plugins in v2 (AgentEditor has no add), so guide the user
    // to the one required copy step instead of failing or writing into their repo.
    let warned = false
    await ctx.agent.transform((editor) => {
      if (warned) return
      warned = true
      const ids = new Set<string>(editor.list().map((agent) => String(agent.id)))
      const have = installedAgentVersion(ctx.location.directory)
      const want = packageVersion()
      const initCmd = "npx @haylan/opencode-pocock init"
      if (!AGENT_IDS.some((id) => ids.has(id))) {
        console.warn(
          `pocock: skills loaded, but the pocock agents are not installed — run: ${initCmd}`,
        )
      } else if (have !== want) {
        console.warn(
          `pocock: installed agents are ${have ? `from v${have}` : "unversioned"}, package is v${want} — refresh: ${initCmd}`,
        )
      }
    })
  },
})

export { packageRoot }