// Migration workflow: options modal → progress → results view

import { api } from './api.js';
import { state, setState } from './state.js';
import { escHtml, formatDateTime, downloadCsv, renderFieldIssues, bindFieldIssueToggles } from './utils.js';
import { navigate } from './router.js';
import { refreshTemplates } from './templates.js';

// ── Helpers ────────────────────────────────────────────────────────────────

const _RESULTS_STORAGE_KEY = 'migrator_last_batch_results';

function getSettings() {
  try { return JSON.parse(localStorage.getItem('migrator_settings')) || {}; }
  catch { return {}; }
}

function persistLastResults(results) {
  try {
    sessionStorage.setItem(_RESULTS_STORAGE_KEY, JSON.stringify(results));
  } catch {
    // Best-effort only.
  }
}

function loadPersistedResults() {
  try {
    const raw = sessionStorage.getItem(_RESULTS_STORAGE_KEY);
    return raw ? JSON.parse(raw) : null;
  } catch {
    return null;
  }
}

function buildResultsFromHistory(history) {
  if (!history || !history.length) return null;

  const sorted = [...history].sort((a, b) => String(b.timestamp || '').localeCompare(String(a.timestamp || '')));
  const newestTimestamp = sorted[0]?.timestamp;
  const recentBatch = sorted.filter(item => item.timestamp === newestTimestamp);
  if (!recentBatch.length) return null;

  return {
    status: 'completed',
    completed_at: newestTimestamp,
    results: recentBatch,
    summary: {
      total: recentBatch.length,
      success: recentBatch.filter(r => r.status === 'success').length,
      failed: recentBatch.filter(r => r.status === 'failed' || r.status === 'blocked').length,
      skipped: recentBatch.filter(r => r.status === 'skipped').length,
      dry_run: recentBatch.filter(r => r.status === 'dry_run').length,
    },
    recovered_from_history: true,
  };
}

// ── Options modal ──────────────────────────────────────────────────────────

export function showOptionsModal(ids) {
  if (!ids || !ids.length) return;
  const settings = getSettings();
  const names = ids.map(id => {
    const t = state.templates.find(t => t.adobe_id === id);
    return t ? t.name : id;
  });

  const existing = document.getElementById('migration-modal');
  if (existing) existing.remove();

  const wrapper = document.createElement('div');
  wrapper.id = 'migration-modal';
  wrapper.innerHTML = `
    <div class="modal-backdrop"></div>
    <div class="modal-box">
      <div class="modal-header">
        <span class="modal-title">Migration Options</span>
        <button class="modal-close" id="mm-close">✕</button>
      </div>
      <div class="modal-body">
        <div class="callout info" style="margin-bottom:16px">
          <span class="callout-icon">📋</span>
          <span>Migrating <strong>${ids.length}</strong> template${ids.length > 1 ? 's' : ''}:
            ${names.slice(0, 3).map(n => `<em>${escHtml(n)}</em>`).join(', ')}${names.length > 3 ? `… +${names.length - 3} more` : ''}</span>
        </div>

        <div class="options-panel">
          <div class="options-title">Options</div>

          <div class="option-row">
            <button class="toggle" id="opt-dry-run" role="switch" aria-checked="false"></button>
            <div class="option-body">
              <div class="option-label">Dry Run</div>
              <div class="option-desc">Validate and preview without creating Docusign templates</div>
            </div>
          </div>

          <div class="option-row">
            <button class="toggle" id="opt-overwrite" role="switch"
              aria-checked="${settings.defaultOverwrite ? 'true' : 'false'}"
              class="toggle ${settings.defaultOverwrite ? 'on' : ''}"></button>
            <div class="option-body">
              <div class="option-label">Overwrite Existing</div>
              <div class="option-desc">Update Docusign templates that already exist (default: skip)</div>
            </div>
          </div>

          <div class="option-row">
            <button class="toggle on" id="opt-include-docs" role="switch" aria-checked="true"></button>
            <div class="option-body">
              <div class="option-label">Include Documents</div>
              <div class="option-desc">Embed PDFs in the Docusign template payload</div>
            </div>
          </div>

          <div class="option-row" style="align-items:center">
            <div class="option-body">
              <div class="option-label">Target Folder <span class="form-label-sub">(optional)</span></div>
              <input type="text" class="form-input" id="opt-folder"
                     placeholder="e.g. Migrated Templates" style="margin-top:6px" />
            </div>
          </div>
        </div>
      </div>
      <div class="modal-footer">
        <button class="btn btn-secondary" id="mm-cancel">Cancel</button>
        <button class="btn btn-primary" id="mm-run">Run Migration →</button>
      </div>
    </div>
  `;
  document.body.appendChild(wrapper);

  // Wire toggles
  wrapper.querySelectorAll('.toggle').forEach(btn => {
    if (settings.defaultOverwrite && btn.id === 'opt-overwrite') btn.classList.add('on');
    btn.addEventListener('click', () => {
      btn.classList.toggle('on');
      btn.setAttribute('aria-checked', btn.classList.contains('on'));
    });
  });

  document.getElementById('mm-close').onclick  = () => wrapper.remove();
  document.getElementById('mm-cancel').onclick = () => wrapper.remove();
  document.getElementById('mm-run').onclick    = () => _startMigration(ids, wrapper);
}

// ── Start migration ────────────────────────────────────────────────────────

async function _startMigration(ids, wrapper) {
  const dryRun      = document.getElementById('opt-dry-run')?.classList.contains('on') || false;
  const overwrite   = document.getElementById('opt-overwrite')?.classList.contains('on') || false;
  const includeDocs = !(document.getElementById('opt-include-docs')?.classList.contains('on') === false);
  const folder      = document.getElementById('opt-folder')?.value.trim() || undefined;

  // Replace modal body with progress view
  const body   = wrapper.querySelector('.modal-body');
  const footer = wrapper.querySelector('.modal-footer');
  wrapper.querySelector('.modal-title').textContent = dryRun ? 'Dry Run' : 'Migrating…';
  footer.innerHTML = ''; // hide footer during migration

  const names = ids.map(id => {
    const t = state.templates.find(t => t.adobe_id === id);
    return { id, name: t ? t.name : id };
  });

  body.innerHTML = `
    <div class="migration-progress">
      <div class="progress-wrap">
        <div class="progress-label">
          <span id="prog-label">Starting…</span>
          <span id="prog-count">0 / ${ids.length}</span>
        </div>
        <div class="progress-bar"><div class="progress-fill" id="prog-bar" style="width:0%"></div></div>
      </div>
      <div class="progress-template-list" id="prog-list">
        ${names.map(n => `
          <div class="progress-template-row" id="prog-row-${escHtml(n.id)}">
            <div class="progress-template-name">${escHtml(n.name)}</div>
            <span class="progress-template-status spinner spinner-sm"></span>
          </div>`).join('')}
      </div>
    </div>
  `;

  try {
    const jobData = await api.migrate.batch({
      source_template_ids: ids,
      target_folder: folder,
      options: { dry_run: dryRun, overwrite_if_exists: overwrite, include_documents: includeDocs },
    });

    const jobId = jobData.job_id;
    await pollJob(jobId, (progress) => {
      const { completed, total } = progress.progress || { completed: 0, total: ids.length };
      const pct = total > 0 ? Math.round(completed / total * 100) : 0;
      document.getElementById('prog-bar')  && (document.getElementById('prog-bar').style.width = pct + '%');
      document.getElementById('prog-count')&& (document.getElementById('prog-count').textContent = `${completed} / ${total}`);
      document.getElementById('prog-label')&& (document.getElementById('prog-label').textContent = `Migrating… ${pct}%`);

      // Update per-template icons as results come in
      (progress.results || []).forEach(r => {
        const row = document.getElementById(`prog-row-${r.adobe_template_id}`);
        if (!row) return;
        const statusEl = row.querySelector('.progress-template-status');
        if (!statusEl) return;
        statusEl.className = 'progress-template-status';
        if (r.status === 'success')      statusEl.textContent = r.action === 'created' ? '✅' : r.action === 'dry_run' ? '🔍' : '✏️';
        else if (r.status === 'skipped') statusEl.textContent = '⏭';
        else if (r.status === 'blocked') statusEl.textContent = '🚫';
        else                             statusEl.textContent = '❌';

        if (r.status === 'blocked' || r.status === 'error' || r.status === 'failed') {
          const msg = r.error || (r.blockers||[])[0] || 'Migration failed';
          let hint = row.querySelector('.progress-template-error');
          if (!hint) {
            hint = document.createElement('div');
            hint.className = 'progress-template-error';
            row.appendChild(hint);
          }
          hint.textContent = msg;
        }
      });
    });

    // Migration done — show "View Results" button
    const allResults = (jobData.results || []);
    const failCount  = allResults.filter(r => r.status === 'blocked' || r.status === 'error' || r.status === 'failed').length;
    document.getElementById('prog-label') && (document.getElementById('prog-label').textContent = 'Done!');

    if (failCount > 0) {
      const hint = document.createElement('div');
      hint.style.cssText = 'font-size:12px;color:var(--text-muted);margin-top:10px;text-align:center';
      hint.textContent = `${failCount} template${failCount > 1 ? 's' : ''} had issues — select View Results for details.`;
      body.appendChild(hint);
    }

    footer.innerHTML = `
      <button class="btn btn-secondary" id="mm-close-done">Close</button>
      <button class="btn btn-primary" id="mm-view-results">View Results →</button>
    `;
    document.getElementById('mm-close-done').onclick   = () => wrapper.remove();
    document.getElementById('mm-view-results').onclick = () => {
      wrapper.remove();
      navigate('#/results');
    };

    // Refresh template list
    await refreshTemplates();
    state.selectedIds.clear();

  } catch (err) {
    body.innerHTML += `<div class="callout error" style="margin-top:12px">
      <span class="callout-icon">❌</span> Migration failed: ${escHtml(err.message)}
    </div>`;
    footer.innerHTML = `<button class="btn btn-secondary" id="mm-err-close">Close</button>`;
    document.getElementById('mm-err-close').onclick = () => wrapper.remove();
  }
}

// ── Poll batch job ─────────────────────────────────────────────────────────

export async function pollJob(jobId, onProgress) {
  const POLL_MS = 2000;
  const MAX_WAIT = 300000; // 5 minutes
  const started = Date.now();

  return new Promise((resolve, reject) => {
    const tick = async () => {
      try {
        const data = await api.migrate.batchStatus(jobId);
        if (onProgress) onProgress(data);

        if (data.status === 'done' || data.status === 'complete' || data.status === 'completed') {
          setState('lastMigrationResults', data);
          persistLastResults(data);
          resolve(data);
        } else if (data.status === 'failed') {
          reject(new Error('Migration job failed'));
        } else if (Date.now() - started > MAX_WAIT) {
          reject(new Error('Migration timed out'));
        } else {
          setTimeout(tick, POLL_MS);
        }
      } catch (e) {
        reject(e);
      }
    };
    tick();
  });
}

// ── Results view ───────────────────────────────────────────────────────────

export async function renderResults() {
  const outlet = document.getElementById('router-outlet');
  let results = state.lastMigrationResults || loadPersistedResults();

  if (!results) {
    try {
      const data = await api.migrate.history();
      results = buildResultsFromHistory(data.history || []);
    } catch {
      results = null;
    }
  }

  if (results) {
    setState('lastMigrationResults', results);
    persistLastResults(results);
  }

  if (!results) {
    outlet.innerHTML = `
      <div class="empty-state">
        <div class="empty-state-icon">📊</div>
        <div class="empty-state-title">No migration results yet</div>
        <div class="empty-state-sub">Run a migration from the <a href="#/templates" style="color:var(--cobalt)">Templates</a> view to see results here. If templates already exist in DocuSign, use History &amp; Audit to review older runs.</div>
      </div>`;
    return;
  }

  const templateResults = results.results || [];
  const summary = {
    created:  templateResults.filter(r => r.action === 'created').length,
    updated:  templateResults.filter(r => r.action === 'updated').length,
    skipped:  templateResults.filter(r => r.status === 'skipped').length,
    blocked:  templateResults.filter(r => r.status === 'blocked').length,
    errors:   templateResults.filter(r => r.status === 'error').length,
    dry_run:  templateResults.filter(r => r.status === 'dry_run').length,
  };

  const migratedIds = templateResults
    .filter(r => r.status === 'success')
    .map(r => r.adobe_template_id);

  outlet.innerHTML = `
    <div class="page-header">
      <div>
        <div class="page-title">Migration Results</div>
        <div class="page-subtitle">${formatDateTime(results.completed_at || new Date().toISOString())}</div>
      </div>
      <div class="page-actions">
        <button class="btn btn-secondary btn-sm" id="btn-export-results">⬇ Export CSV</button>
        ${migratedIds.length ? `<button class="btn btn-primary btn-sm" id="btn-verify-results">Verify Templates →</button>` : ''}
      </div>
    </div>

    ${results.recovered_from_history ? `
      <div class="callout info">
        <span class="callout-icon">ℹ️</span>
        These results were recovered from recent migration history after the page state was reset.
      </div>
    ` : ''}

    <!-- Summary stat cards -->
    <div class="stat-grid" style="grid-template-columns:repeat(${summary.dry_run ? 6 : 5},1fr)">
      <div class="stat-card green">
        <div class="stat-label">Created</div>
        <div class="stat-value">${summary.created}</div>
      </div>
      <div class="stat-card blue">
        <div class="stat-label">Updated</div>
        <div class="stat-value">${summary.updated}</div>
      </div>
      <div class="stat-card gray">
        <div class="stat-label">Skipped</div>
        <div class="stat-value">${summary.skipped}</div>
      </div>
      <div class="stat-card red">
        <div class="stat-label">Blocked</div>
        <div class="stat-value">${summary.blocked}</div>
      </div>
      <div class="stat-card red">
        <div class="stat-label">Errors</div>
        <div class="stat-value">${summary.errors}</div>
      </div>
      ${summary.dry_run ? `<div class="stat-card gray"><div class="stat-label">Dry Run</div><div class="stat-value">${summary.dry_run}</div></div>` : ''}
    </div>

    <!-- Per-template results -->
    <div class="card">
      <div class="card-header">
        <span class="card-title">Per-Template Results</span>
      </div>
      <div id="results-list" style="padding:8px 16px">
        ${templateResults.map(r => _resultRow(r)).join('')}
      </div>
    </div>

    <div style="display:flex;gap:8px;margin-top:8px">
      <a href="#/templates" class="btn btn-secondary btn-sm">← Back to Templates</a>
    </div>
  `;

  // Expand/collapse result rows
  document.querySelectorAll('.result-header').forEach(hdr => {
    hdr.addEventListener('click', () => {
      hdr.parentElement.classList.toggle('open');
    });
  });

  bindFieldIssueToggles();

  // Export CSV
  document.getElementById('btn-export-results')?.addEventListener('click', () => {
    downloadCsv('migration-results.csv', templateResults.map(r => ({
      name: r.adobe_template_name || r.adobe_template_id,
      adobe_id: r.adobe_template_id,
      docusign_id: r.docusign_template_id || '',
      status: r.status,
      action: r.action || '',
      warnings: (r.warnings || []).join('; '),
    })));
  });

  // Verify button
  document.getElementById('btn-verify-results')?.addEventListener('click', () => {
    import('./verification.js').then(m => {
      setState('verifyIds', migratedIds);
      navigate('#/verify');
    });
  });
}

function _resultRow(r) {
  const issues   = r.field_issues || [];
  const warnings = r.warnings || [];
  const hasDetail = warnings.length || r.error || issues.length;

  const icon = r.status === 'success'
    ? (issues.length ? '⚠️' : r.action === 'created' ? '✅' : r.action === 'dry_run' ? '🔍' : '✏️')
    : (r.status === 'skipped' ? '⏭' : r.status === 'blocked' ? '🚫' : '❌');

  const statusBadge = r.status === 'success'
    ? `<span class="badge badge-green">${r.action || 'success'}</span>${issues.length ? '<span class="badge badge-amber">partial</span>' : ''}`
    : `<span class="badge badge-${r.status === 'skipped' ? 'gray' : 'red'}">${r.status}</span>`;

  return `
    <div class="result-row">
      <div class="result-header">
        <span class="result-icon">${icon}</span>
        <span class="result-name">${escHtml(r.adobe_template_name || r.adobe_template_id)}</span>
        ${statusBadge}
        ${r.docusign_template_id ? `<span class="ds-pill" title="${escHtml(r.docusign_template_id)}">DS: ${escHtml(r.docusign_template_id.slice(0,8))}…</span>` : ''}
        ${issues.length ? `<span class="result-meta">⚠ ${issues.length} field issue${issues.length > 1 ? 's' : ''}</span>` : ''}
        ${warnings.length ? `<span class="result-meta">${warnings.length} warning${warnings.length > 1 ? 's' : ''}</span>` : ''}
      </div>
      ${hasDetail ? `
        <div class="result-body">
          ${warnings.map(w => `<div class="result-warn-item"><span class="ri">⚠</span>${escHtml(w)}</div>`).join('')}
          ${r.error ? `<div class="result-warn-item" style="color:var(--error)"><span class="ri">❌</span>${escHtml(r.error)}</div>` : ''}
          ${renderFieldIssues(issues)}
        </div>` : ''}
    </div>
  `;
}