'use strict';

/**
 * /api/content (Session 29)
 *
 * Structured content objects generated from live VYNDR data, degrading
 * gracefully by data level. Read-only, zero-credit (reads cached data).
 * `?format=text` additionally returns post-ready plain text.
 *
 *   GET /api/content/slate/:sport            → daily slate thread
 *   GET /api/content/potd/:sport             → prop (or game) of the day
 *   GET /api/content/recap/:sport            → results recap (needs resolved grades)
 *   GET /api/content/preview/:sport/:gameId  → matchup preview for one game
 */

const express = require('express');
const template = require('../services/contentTemplateService');
const formatter = require('../services/contentFormatter');
const { cacheGet } = require('../utils/redis');

const router = express.Router();

const MISSION_HEADER = { 'X-VYNDR-Mission': 'Every post is a free ad' };
const SUPPORTED = new Set(['nba', 'wnba', 'mlb', 'soccer', 'nfl', 'nhl']);

function guard(req, res) {
  const sport = String(req.params.sport || '').toLowerCase();
  if (!SUPPORTED.has(sport)) {
    res.status(404).set(MISSION_HEADER).json({ error: `No content for sport: ${sport}` });
    return null;
  }
  return sport;
}

router.get('/slate/:sport', async (req, res) => {
  const sport = guard(req, res);
  if (!sport) return undefined;
  try {
    const data = await template.collectSlateData(sport);
    const thread = template.generateSlateThread(sport, data);
    const body = { ...thread };
    if (req.query.format === 'text') body.text = formatter.formatSlateThread(thread);
    return res.set(MISSION_HEADER).json(body);
  } catch (err) {
    console.error(`[content/slate/${sport}]`, err.message);
    return res.status(500).set(MISSION_HEADER).json({ error: 'Content generation failed' });
  }
});

router.get('/potd/:sport', async (req, res) => {
  const sport = guard(req, res);
  if (!sport) return undefined;
  try {
    const data = await template.collectSlateData(sport);
    const potd = template.generatePOTD(sport, data);
    const body = { ...potd };
    if (req.query.format === 'text') body.text = formatter.formatPOTD(potd);
    return res.set(MISSION_HEADER).json(body);
  } catch (err) {
    console.error(`[content/potd/${sport}]`, err.message);
    return res.status(500).set(MISSION_HEADER).json({ error: 'Content generation failed' });
  }
});

router.get('/recap/:sport', async (req, res) => {
  const sport = guard(req, res);
  if (!sport) return undefined;
  try {
    // Resolved grades land in a daily cache when the grading flow settles.
    const utc = new Date().toISOString().split('T')[0];
    const cache = (await cacheGet(`results:${sport}:${utc}`)) ?? (await cacheGet(`results:${sport}`));
    const resolved = Array.isArray(cache) ? cache : Array.isArray(cache?.grades) ? cache.grades : [];
    const recap = template.generateResultsRecap(sport, resolved);
    const body = { ...recap };
    if (req.query.format === 'text') body.text = formatter.formatRecap(recap);
    return res.set(MISSION_HEADER).json(body);
  } catch (err) {
    console.error(`[content/recap/${sport}]`, err.message);
    return res.status(500).set(MISSION_HEADER).json({ error: 'Content generation failed' });
  }
});

router.get('/preview/:sport/:gameId', async (req, res) => {
  const sport = guard(req, res);
  if (!sport) return undefined;
  const { gameId } = req.params;
  try {
    const data = await template.collectSlateData(sport);
    const game = (data.schedule || []).find((g) => String(g.id) === String(gameId));
    if (!game) {
      return res.status(404).set(MISSION_HEADER).json({ error: 'Game not on today\'s schedule.' });
    }
    const lines = template.__internals.findGameLinesFor(game, data.gameLines);
    const preview = template.generateMatchupPreview(game, lines, data.streaks);
    return res.set(MISSION_HEADER).json(preview);
  } catch (err) {
    console.error(`[content/preview/${sport}]`, err.message);
    return res.status(500).set(MISSION_HEADER).json({ error: 'Content generation failed' });
  }
});

module.exports = router;