/**
 * Report rendering. Pure string building so the output format is testable and
 * the CLI stays a thin shell.
 */

import type { AuditReport, FlatNode } from './types';

function ruleSummary(
  nodes: FlatNode[]
): Array<{ rule: string; impact: string; count: number; helpUrl: string; help: string }> {
  const byRule = new Map<
    string,
    { rule: string; impact: string; count: number; helpUrl: string; help: string }
  >();
  for (const node of nodes) {
    const existing = byRule.get(node.rule);
    if (existing) existing.count += 1;
    else
      byRule.set(node.rule, {
        rule: node.rule,
        impact: node.impact,
        count: 1,
        helpUrl: node.helpUrl,
        help: node.help,
      });
  }
  return [...byRule.values()].sort((a, b) => b.count - a.count || a.rule.localeCompare(b.rule));
}

/** Human-readable console report. */
export function renderConsole(report: AuditReport): string {
  const lines: string[] = [];
  lines.push('');
  lines.push(`  a11y-audit — ${report.name}`);
  lines.push(
    `  axe-core ${report.axeVersion} · tags: ${report.standard.join(', ')} · failing on: ${report.failOn.join(', ')}`
  );
  lines.push(
    `  base URL: ${report.baseUrl}` +
      (report.blockExternalRequests ? ' (external requests blocked)' : '')
  );
  lines.push('');

  for (const route of report.routes) {
    const status = route.blocking.length === 0 ? 'PASS' : 'FAIL';
    const redirect = route.finalUrl.endsWith(route.route) ? '' : `  ->  ${route.finalUrl}`;
    lines.push(
      `  [${status}] ${route.routeName} @ ${route.viewport}${redirect}` +
        `\n         ${route.blocking.length} blocking · ${route.allowed.length} allowlisted · ` +
        `${route.advisory.length} advisory · ${route.passCount} checks passed · ` +
        `${route.incompleteCount} needs review · ${route.renderedTextLength} chars rendered` +
        `${route.domSettled ? '' : ' (DOM never went quiet)'}`
    );
    for (const entry of ruleSummary(route.blocking)) {
      lines.push(`           x ${entry.rule} (${entry.impact}) x${entry.count} — ${entry.help}`);
      for (const node of route.blocking.filter((n) => n.rule === entry.rule).slice(0, 5)) {
        lines.push(`               ${node.target.join(' , ')}`);
      }
      const hidden = route.blocking.filter((n) => n.rule === entry.rule).length - 5;
      if (hidden > 0) lines.push(`               ... and ${hidden} more node(s)`);
      lines.push(`               ${entry.helpUrl}`);
    }
    for (const node of route.allowed) {
      lines.push(
        `           ~ ${node.rule} (${node.impact}) allowlisted [#${node.allowlistIndex}` +
          `${node.allowlistTicket ? ` ${node.allowlistTicket}` : ''}]: ${node.allowlistReason}`
      );
    }
  }

  lines.push('');
  lines.push(
    `  TOTAL: ${report.totals.blocking} blocking · ${report.totals.allowed} allowlisted · ` +
      `${report.totals.advisory} advisory across ${report.totals.routesAudited} route/viewport runs`
  );

  if (report.expiredAllowlistEntries.length > 0) {
    lines.push('');
    lines.push('  EXPIRED allowlist entries (they no longer suppress anything):');
    for (const entry of report.expiredAllowlistEntries) {
      lines.push(`    - allowlist[${entry.index}] ${entry.rule} expired ${entry.expires}`);
    }
  }

  if (report.staleAllowlistEntries.length > 0) {
    lines.push('');
    lines.push('  STALE allowlist entries (matched nothing this run — delete them):');
    for (const entry of report.staleAllowlistEntries) {
      lines.push(`    - allowlist[${entry.index}] ${entry.rule}: ${entry.reason}`);
    }
  }

  lines.push('');
  return lines.join('\n');
}

/** GitHub step-summary flavoured markdown. */
export function renderMarkdown(report: AuditReport): string {
  const lines: string[] = [];
  const verdict = report.totals.blocking === 0 ? 'PASS' : 'FAIL';
  lines.push(`## Accessibility (WCAG 2.1 AA) — ${report.name}: ${verdict}`);
  lines.push('');
  lines.push(
    `axe-core \`${report.axeVersion}\`, tags \`${report.standard.join(', ')}\`, failing on ` +
      `\`${report.failOn.join(', ')}\`.`
  );
  lines.push('');
  lines.push('| Route | Viewport | Blocking | Allowlisted | Advisory |');
  lines.push('| --- | --- | ---: | ---: | ---: |');
  for (const route of report.routes) {
    lines.push(
      `| \`${route.routeName}\` | ${route.viewport} | ${route.blocking.length} | ` +
        `${route.allowed.length} | ${route.advisory.length} |`
    );
  }

  const allBlocking = report.routes.flatMap((r) => r.blocking);
  if (allBlocking.length > 0) {
    lines.push('');
    lines.push('### Blocking violations');
    lines.push('');
    lines.push('| Rule | Impact | Nodes | Help |');
    lines.push('| --- | --- | ---: | --- |');
    for (const entry of ruleSummary(allBlocking)) {
      lines.push(
        `| \`${entry.rule}\` | ${entry.impact} | ${entry.count} | [${entry.help}](${entry.helpUrl}) |`
      );
    }
  }

  if (report.staleAllowlistEntries.length > 0 || report.expiredAllowlistEntries.length > 0) {
    lines.push('');
    lines.push('### Allowlist hygiene');
    for (const entry of report.expiredAllowlistEntries) {
      lines.push(`- expired: \`allowlist[${entry.index}]\` \`${entry.rule}\` (${entry.expires})`);
    }
    for (const entry of report.staleAllowlistEntries) {
      lines.push(`- stale: \`allowlist[${entry.index}]\` \`${entry.rule}\` matched nothing`);
    }
  }

  lines.push('');
  return lines.join('\n');
}