/**
 * Inline sparkline embeds for QVAC chat from tool results / agent chart actions.
 */
import { drawChart, seriesColor } from '../charts.js'

/**
 * Extract chart ids from tool log for embedding.
 * @param {Array<{ name: string, args?: object, result?: any }>} toolLog
 * @returns {string[]}
 */
export function chartIdsFromToolLog(toolLog) {
  /** @type {string[]} */
  const ids = []
  const push = (id) => {
    const s = String(id || '').trim()
    if (s && !ids.includes(s)) ids.push(s)
  }
  for (const t of toolLog || []) {
    const n = t.name || ''
    const a = t.args || {}
    const r = t.result || {}
    if (
      n === 'show_charts' ||
      n === 'open_chart' ||
      n === 'pin_charts' ||
      n === 'set_chart_type' ||
      n === 'summarize_chart' ||
      n === 'query_metric' ||
      n === 'compare_chart_windows'
    ) {
      if (a.chart) push(a.chart)
      if (a.id) push(a.id)
      if (a.charts) {
        String(a.charts)
          .split(/[\s,]+/)
          .filter(Boolean)
          .forEach(push)
      }
      if (Array.isArray(r.charts)) r.charts.forEach(push)
      if (r.chart) push(r.chart)
      if (r.focus) push(r.focus)
    }
    if (n === 'hot_metrics' && Array.isArray(r.results)) {
      for (const row of r.results.slice(0, 4)) push(row.chart)
    }
    if (n === 'search_charts' && Array.isArray(r.results)) {
      for (const row of r.results.slice(0, 3)) push(row.id)
    }
  }
  return ids.slice(0, 6)
}

/**
 * Mount sparklines under a message element.
 * @param {HTMLElement} msgEl
 * @param {string[]} chartIds
 * @param {{
 *   request: (method: string, args?: object) => Promise<any>,
 *   catalog?: Record<string, object>,
 *   onOpen?: (id: string) => void,
 * }} deps
 */
export async function mountChartEmbeds(msgEl, chartIds, deps) {
  if (!msgEl || !chartIds?.length || !deps?.request) return
  let host = msgEl.querySelector('.qvac-chart-embeds')
  if (host) host.remove()
  host = document.createElement('div')
  host.className = 'qvac-chart-embeds'
  msgEl.appendChild(host)

  for (const id of chartIds) {
    const card = document.createElement('button')
    card.type = 'button'
    card.className = 'qvac-chart-embed'
    card.title = `Open ${id} on Charts wall`
    const title = deps.catalog?.[id]?.title || id
    card.innerHTML = `<header><span class="qvac-chart-embed-id">${escapeHtml(id)}</span><span class="muted">${escapeHtml(title)}</span></header><canvas width="320" height="72"></canvas><footer class="muted">Loading…</footer>`
    card.addEventListener('click', () => deps.onOpen?.(id))
    host.appendChild(card)
    const canvas = card.querySelector('canvas')
    const footer = card.querySelector('footer')
    try {
      const q = await deps.request('queryData', {
        chart: id,
        after: -180,
        points: 90,
        group: 'average',
      })
      const labels = (q.labels || []).filter((l) => l && l !== 'time')
      const data = Array.isArray(q.data) ? q.data : []
      if (!labels.length || !data.length) {
        if (footer) footer.textContent = 'No points'
        continue
      }
      // Prefer up to 3 interesting dims
      /** @type {Array<{ values: number[], color: string, label: string }>} */
      const lines = []
      for (let di = 0; di < Math.min(3, labels.length); di++) {
        const vals = data
          .map((row) => Number(row[di + 1]))
          .filter((v) => Number.isFinite(v))
        if (vals.length < 2) continue
        // Pad to full length with nulls as 0 for sparkline simplicity
        const full = data.map((row) => {
          const v = Number(row[di + 1])
          return Number.isFinite(v) ? v : 0
        })
        lines.push({
          values: full,
          color: seriesColor(di),
          label: labels[di],
        })
      }
      if (!lines.length) {
        if (footer) footer.textContent = 'No numeric dims'
        continue
      }
      if (canvas) {
        drawChart(canvas, lines, {
          maxPoints: 90,
          showYAxis: false,
          padLeft: 4,
          mode: 'area',
          emptyMessage: '',
        })
      }
      const last = lines[0].values[lines[0].values.length - 1]
      if (footer) {
        footer.textContent = `${lines.map((l) => l.label).join(', ')} · last ${formatNum(last)}`
      }
    } catch (err) {
      if (footer) footer.textContent = err?.message || 'query failed'
    }
  }
}

function formatNum(v) {
  const n = Number(v)
  if (!Number.isFinite(n)) return '—'
  if (Math.abs(n) >= 100) return n.toFixed(0)
  if (Math.abs(n) >= 10) return n.toFixed(1)
  return n.toFixed(2)
}

function escapeHtml(s) {
  return String(s || '')
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
}