import { mkdir, readFile, writeFile } from 'node:fs/promises';
import { dirname, join } from 'node:path';
import { homedir } from 'node:os';

const DEFAULT_STATE_PATH = join(homedir(), '.config', 'sin', 'sin-code-datascience', 'onboarding-state.json');

type OnboardingState = {
  ownerEmail?: string;
  notes?: string;
  updatedAt?: string;
};

export type TemplateAgentAction =
  | { action: 'agent.help' }
  | { action: 'sin.code.datascience.health' }
  | { action: 'sin.code.datascience.onboarding.status' }
  | { action: 'sin.code.datascience.onboarding.save'; ownerEmail?: string; notes?: string; confirm?: boolean };

export async function executeTemplateAgentAction(action: TemplateAgentAction): Promise<unknown> {
  switch (action.action) {
    case 'agent.help':
      return buildHelpPayload();
    case 'sin.code.datascience.health':
      return {
        ok: true,
        agent: 'sin-code-datascience',
        primaryModel: 'opencode/qwen3.6-plus-free',
        team: 'Team Coding',
      };
    case 'sin.code.datascience.onboarding.status':
      return {
        ok: true,
        statePath: DEFAULT_STATE_PATH,
        state: await readState(),
      };
    case 'sin.code.datascience.onboarding.save':
      if (!action.confirm) {
        throw new Error('input_required:confirm=true required');
      }
      return {
        ok: true,
        statePath: DEFAULT_STATE_PATH,
        state: await writeState({
          ownerEmail: clean(action.ownerEmail),
          notes: clean(action.notes),
          updatedAt: new Date().toISOString(),
        }),
      };
  }
}

function buildHelpPayload() {
  return {
    ok: true,
    agent: 'sin-code-datascience',
    actions: ['sin.code.datascience.health', 'sin.code.datascience.onboarding.status', 'sin.code.datascience.onboarding.save'],
    controlPlane: {
      projectionMode: 'control-plane-first',
      capabilityRegistry: 'control_plane.capabilities',
      consumerAuthScript: './scripts/hf_pull_script.py',
      completeInstallScript: './scripts/complete-install.sh',
    },
  };
}

async function readState(): Promise<OnboardingState | null> {
  try {
    return JSON.parse(await readFile(DEFAULT_STATE_PATH, 'utf8')) as OnboardingState;
  } catch {
    return null;
  }
}

async function writeState(state: OnboardingState) {
  await mkdir(dirname(DEFAULT_STATE_PATH), { recursive: true });
  await writeFile(DEFAULT_STATE_PATH, `${JSON.stringify(state, null, 2)}\n`, 'utf8');
  return state;
}

function clean(value: string | undefined) {
  const normalized = String(value || '').trim();
  return normalized || undefined;
}