/**
 * `request_approval` — the model-driven front-end of the approval gate.
 *
 * The owner no longer has to type `/approve <change-id> design|plan`: the model
 * calls this tool, the owner only confirms in the userQuestions dialog, and the
 * approval marker is still written by bundle code (`lib/approval.js`), never by
 * the model. The gates keep their invariant: `approval.md` is written only by
 * the harness after an explicit owner confirmation.
 *
 * The definition is hand-built plain JSON — no `@deepseek-ai/*` imports (the
 * bundle is installed from a local directory, so DSH internals are not
 * resolvable). `parameters` is object-rooted raw JSON Schema; DSH performs no
 * argument validation, so `execute` validates the args itself and always
 * returns the lossless `{ approved, message }` shape.
 *
 * `userQuestions` is resolved lazily (injected as `getUserQuestions`) and never
 * declared in `inject`: a missing service must refuse this tool, not park the
 * whole bundle. Likewise `getWorkingDirectory` is a service factory, because
 * the repo root depends on the receiving agent's session.
 */

import { resolve } from 'node:path'
import { CHANGE_ID, KINDS, runApproval } from './lib/approval.js'

const APPROVE_LABEL = 'Approve'
const CANCEL_LABEL = 'Cancel'
const USAGE =
  "usage: request_approval { change_id: '<id>', kind: 'design' | 'plan' }"

/** Session working directory of the receiving agent; process.cwd() fallback. */
function repoRootOf(getWorkingDirectory, agent) {
  try {
    const workingDirectory = getWorkingDirectory?.()
    const cwd = workingDirectory?.get?.(agent?.session)
    if (typeof cwd === 'string' && cwd !== '') return resolve(cwd)
  } catch {
    // Fall through to the process directory.
  }
  return process.cwd()
}

function refusal(message) {
  return { approved: false, message }
}

/**
 * Build the tool definition.
 *
 * @param {{
 *   getWorkingDirectory?: () => { get(session: unknown): string } | undefined,
 *   getUserQuestions?: () => { ask(request: unknown): Promise<unknown> } | null,
 *   logger?: { warn?: Function },
 *   now?: () => Date,
 * }} deps
 */
export function createApproveTool({ getWorkingDirectory, getUserQuestions, logger, now = () => new Date() } = {}) {
  return {
    name: 'request_approval',
    description:
      'Ask the owner to approve an OpenSpec change design or an implementation plan. The approval marker is written by the harness only after the owner confirms.',
    parameters: {
      type: 'object',
      properties: {
        change_id: {
          type: 'string',
          description: 'Change id under openspec/changes/<id>/',
        },
        kind: {
          type: 'string',
          enum: ['design', 'plan'],
          description: 'What is being approved',
        },
      },
      required: ['change_id', 'kind'],
      additionalProperties: false,
    },
    output: {
      schema: {
        type: 'object',
        properties: {
          approved: { type: 'boolean' },
          message: { type: 'string' },
        },
        required: ['approved', 'message'],
        additionalProperties: false,
      },
      render(args, value) {
        return [{ type: 'text', text: value.message }]
      },
    },
    async execute(args, exec = {}) {
      try {
        const changeId = typeof args?.change_id === 'string' ? args.change_id.trim() : ''
        const kind = args?.kind

        if (changeId === '') {
          return refusal(`Missing change_id. ${USAGE}`)
        }
        if (!CHANGE_ID.test(changeId)) {
          return refusal(`Invalid change id "${changeId}". ${USAGE}`)
        }
        if (!KINDS.includes(kind)) {
          return refusal(`Unknown kind "${String(kind)}". ${USAGE}`)
        }

        const userQuestions = getUserQuestions?.() ?? null
        if (typeof userQuestions?.ask !== 'function') {
          return refusal(
            'userQuestions service unavailable; request_approval requires the owner dialog (use /approve).',
          )
        }

        // The ask implementation of this front-end: mirrors the /approve
        // dialog, but a `selected[0] === 'Approve'` answer is the only yes.
        const ask = async (questionText) => {
          const answer = await userQuestions.ask({
            questions: [
              {
                id: 'approve',
                question: questionText,
                header: 'Approval gate',
                options: [{ label: APPROVE_LABEL }, { label: CANCEL_LABEL }],
              },
            ],
            ...(exec.agent ? { agent: exec.agent } : {}),
            signal: exec.signal,
          })
          return answer?.answers?.[0]?.selected?.[0] === APPROVE_LABEL
        }

        return await runApproval({
          repoRoot: repoRootOf(getWorkingDirectory, exec.agent),
          changeId,
          kind,
          ask,
          now,
        })
      } catch (error) {
        logger?.warn?.('[dsh-harness] request_approval failed: %s', error?.message ?? error)
        return refusal(String(error?.message ?? error))
      }
    },
  }
}