import type { Context } from 'cordis'
import type { GenerateOptions, StreamChunk } from '@deepseek-ai/dsh-llm'
import { LlmAdapter } from '@deepseek-ai/dsh-llm'

/**
 * Scripted model for the CHILD runtime: answers every request with its own
 * process cwd, so the driving e2e can prove the parent session's workspace
 * reached the child process across the SDK wire. `options` carries the
 * request; the reply depends only on process state.
 */
class CwdEchoAdapter extends LlmAdapter {
  async * stream(options: GenerateOptions): AsyncIterable<StreamChunk> {
    void options
    const reply = `child cwd: ${process.cwd()}`
    yield { type: 'block-start', index: 0, blockType: 'text' }
    yield { type: 'text-delta', index: 0, text: reply }
    yield { type: 'block-end', index: 0, block: { type: 'text', text: reply } }
    yield { type: 'usage', usage: { inputTokens: 3, outputTokens: reply.length } }
    yield { type: 'finish', reason: { kind: 'stop' } }
  }
}

export const name = 'child-mock-llm'
export const inject = ['llm']

/**
 * Register the cwd-echo adapter under the `mock` provider.
 * @param ctx - the plugin context supplying `ctx.llm`.
 */
export function apply(ctx: Context): void {
  ctx.llm.registerAdapter(['mock'], new CwdEchoAdapter())
}