/**
 * @license
 * Copyright 2025 Qwen
 * SPDX-License-Identifier: Apache-2.0
 */

import { SubagentStatsSummary } from './subagent-statistics.js';

function fmtDuration(ms: number): string {
  if (ms < 1000) return `${Math.round(ms)}ms`;
  if (ms < 60000) return `${(ms / 1000).toFixed(1)}s`;
  if (ms < 3600000) {
    const m = Math.floor(ms / 60000);
    const s = Math.floor((ms % 60000) / 1000);
    return `${m}m ${s}s`;
  }
  const h = Math.floor(ms / 3600000);
  const m = Math.floor((ms % 3600000) / 60000);
  return `${h}h ${m}m`;
}

export function formatCompact(
  stats: SubagentStatsSummary,
  taskDesc: string,
): string {
  const sr =
    stats.totalToolCalls > 0
      ? (stats.successRate ??
        (stats.successfulToolCalls / stats.totalToolCalls) * 100)
      : 0;
  const lines = [
    `📋 Task Completed: ${taskDesc}`,
    `🔧 Tool Usage: ${stats.totalToolCalls} calls${stats.totalToolCalls ? `, ${sr.toFixed(1)}% success` : ''}`,
    `⏱️ Duration: ${fmtDuration(stats.totalDurationMs)} | 🔁 Rounds: ${stats.rounds}`,
  ];
  if (typeof stats.totalTokens === 'number') {
    lines.push(
      `🔢 Tokens: ${stats.totalTokens.toLocaleString()}${stats.inputTokens || stats.outputTokens ? ` (in ${stats.inputTokens ?? 0}, out ${stats.outputTokens ?? 0})` : ''}`,
    );
  }
  return lines.join('\n');
}

export function formatDetailed(
  stats: SubagentStatsSummary,
  taskDesc: string,
): string {
  const sr =
    stats.totalToolCalls > 0
      ? (stats.successRate ??
        (stats.successfulToolCalls / stats.totalToolCalls) * 100)
      : 0;
  const lines: string[] = [];
  lines.push(`📋 Task Completed: ${taskDesc}`);
  lines.push(
    `⏱️ Duration: ${fmtDuration(stats.totalDurationMs)} | 🔁 Rounds: ${stats.rounds}`,
  );
  // Quality indicator
  let quality = 'Poor execution';
  if (sr >= 95) quality = 'Excellent execution';
  else if (sr >= 85) quality = 'Good execution';
  else if (sr >= 70) quality = 'Fair execution';
  lines.push(`✅ Quality: ${quality} (${sr.toFixed(1)}% tool success)`);
  // Speed category
  const d = stats.totalDurationMs;
  let speed = 'Long execution - consider breaking down tasks';
  if (d < 10_000) speed = 'Fast completion - under 10 seconds';
  else if (d < 60_000) speed = 'Good speed - under a minute';
  else if (d < 300_000) speed = 'Moderate duration - a few minutes';
  lines.push(`🚀 Speed: ${speed}`);
  lines.push(
    `🔧 Tools: ${stats.totalToolCalls} calls, ${sr.toFixed(1)}% success (${stats.successfulToolCalls} ok, ${stats.failedToolCalls} failed)`,
  );
  if (typeof stats.totalTokens === 'number') {
    lines.push(
      `🔢 Tokens: ${stats.totalTokens.toLocaleString()} (in ${stats.inputTokens ?? 0}, out ${stats.outputTokens ?? 0})`,
    );
  }
  if (stats.toolUsage && stats.toolUsage.length) {
    const sorted = [...stats.toolUsage]
      .sort((a, b) => b.count - a.count)
      .slice(0, 5);
    lines.push('\nTop tools:');
    for (const t of sorted) {
      const avg =
        typeof t.averageDurationMs === 'number'
          ? `, avg ${fmtDuration(Math.round(t.averageDurationMs))}`
          : '';
      lines.push(
        ` - ${t.name}: ${t.count} calls (${t.success} ok, ${t.failure} fail${avg}${t.lastError ? `, last error: ${t.lastError}` : ''})`,
      );
    }
  }
  const tips = generatePerformanceTips(stats);
  if (tips.length) {
    lines.push('\n💡 Performance Insights:');
    for (const tip of tips.slice(0, 3)) lines.push(` - ${tip}`);
  }
  return lines.join('\n');
}

export function generatePerformanceTips(stats: SubagentStatsSummary): string[] {
  const tips: string[] = [];
  const totalCalls = stats.totalToolCalls;
  const sr =
    stats.totalToolCalls > 0
      ? (stats.successRate ??
        (stats.successfulToolCalls / stats.totalToolCalls) * 100)
      : 0;

  // High failure rate
  if (sr < 80)
    tips.push('Low tool success rate - review inputs and error messages');

  // Long duration
  if (stats.totalDurationMs > 60_000)
    tips.push('Long execution time - consider breaking down complex tasks');

  // Token usage
  if (typeof stats.totalTokens === 'number' && stats.totalTokens > 100_000) {
    tips.push(
      'High token usage - consider optimizing prompts or narrowing scope',
    );
  }
  if (typeof stats.totalTokens === 'number' && totalCalls > 0) {
    const avgTokPerCall = stats.totalTokens / totalCalls;
    if (avgTokPerCall > 5_000)
      tips.push(
        `High token usage per tool call (~${Math.round(avgTokPerCall)} tokens/call)`,
      );
  }

  // Network failures
  const isNetworkTool = (name: string) => /web|fetch|search/i.test(name);
  const hadNetworkFailure = (stats.toolUsage || []).some(
    (t) =>
      isNetworkTool(t.name) &&
      t.lastError &&
      /timeout|network/i.test(t.lastError),
  );
  if (hadNetworkFailure)
    tips.push(
      'Network operations had failures - consider increasing timeout or checking connectivity',
    );

  // Slow tools
  const slow = (stats.toolUsage || [])
    .filter((t) => (t.averageDurationMs ?? 0) > 10_000)
    .sort((a, b) => (b.averageDurationMs ?? 0) - (a.averageDurationMs ?? 0));
  if (slow.length)
    tips.push(
      `Consider optimizing ${slow[0].name} operations (avg ${fmtDuration(Math.round(slow[0].averageDurationMs!))})`,
    );

  return tips;
}