class CopilotAction {
  constructor($UD, context) {
    this.$UD = $UD;
    this.context = context;
    this.config = {
      url: '',
      refreshRate: '4',
    };
    this.refreshTimer = null;
    this.debounceTimer = 0;
  }

  setActive() {}

  onClear() {
    if (this.refreshTimer) {
      clearInterval(this.refreshTimer);
      this.refreshTimer = null;
    }
    if (this.debounceTimer) {
      clearTimeout(this.debounceTimer);
      this.debounceTimer = 0;
    }
  }

  setParams(jsn) {
    this.config = Object.assign(this.config, (jsn && jsn.param) || {});
    this.start();
  }

  onRun() {
    this.fetchData();
  }

  start() {
    this.onClear();
    this.fetchData();
    const duration = this.getRefreshDuration();
    if (duration > 0) {
      this.refreshTimer = setInterval(() => this.fetchData(), duration * 60 * 1000);
    }
  }

  async fetchData() {
    if (this.debounceTimer) clearTimeout(this.debounceTimer);
    this.debounceTimer = setTimeout(async () => {
      if (!this.config.url) {
        this.renderGauge(null);
        return;
      }
      try {
        const response = await fetch(this.config.url);
        const text = await response.text();
        const value = this.parsePrometheus(text);
        this.renderGauge(value !== null ? parseFloat(value) : null);
      } catch (e) {
        this.renderGauge(null);
      }
    }, 300);
  }

  parsePrometheus(text) {
    for (const line of text.split('\n')) {
      const trimmed = line.trim();
      if (!trimmed || trimmed.startsWith('#')) continue;
      if (trimmed.startsWith('github_copilot_usage_percentage')) {
        const closingBrace = trimmed.indexOf('}');
        if (closingBrace !== -1) return trimmed.slice(closingBrace + 1).trim();
        // no labels
        const parts = trimmed.split(/\s+/);
        if (parts.length >= 2) return parts[1];
      }
    }
    return null;
  }

  renderGauge(value) {
    const canvas = document.createElement('canvas');
    canvas.width = 196;
    canvas.height = 196;
    const ctx = canvas.getContext('2d');

    ctx.fillStyle = '#000000';
    ctx.fillRect(0, 0, 196, 196);

    const cx = 98, cy = 100;
    const r = 68;
    const lineWidth = 14;

    // Gauge runs from 225° to 315° clockwise (270° sweep)
    const startAngle = 135 * Math.PI / 180;
    const totalSweep = 270 * Math.PI / 180;
    const greenEnd  = startAngle + 0.50 * totalSweep;  // 50%
    const yellowEnd = startAngle + 0.80 * totalSweep;  // 80%
    const endAngle  = startAngle + totalSweep;          // 100%

    // Background track
    ctx.beginPath();
    ctx.arc(cx, cy, r, startAngle, endAngle, false);
    ctx.strokeStyle = '#333333';
    ctx.lineWidth = lineWidth;
    ctx.lineCap = 'round';
    ctx.stroke();

    if (value !== null) {
      const pct = Math.max(0, Math.min(100, value)) / 100;
      const valueAngle = startAngle + pct * totalSweep;

      // Green segment (0–50%)
      if (pct > 0) {
        ctx.beginPath();
        ctx.arc(cx, cy, r, startAngle, Math.min(valueAngle, greenEnd), false);
        ctx.strokeStyle = '#4caf50';
        ctx.lineWidth = lineWidth;
        ctx.lineCap = 'round';
        ctx.stroke();
      }

      // Yellow segment (50–80%)
      if (pct > 0.5) {
        ctx.beginPath();
        ctx.arc(cx, cy, r, greenEnd, Math.min(valueAngle, yellowEnd), false);
        ctx.strokeStyle = '#ffeb3b';
        ctx.lineWidth = lineWidth;
        ctx.lineCap = 'butt';
        ctx.stroke();
      }

      // Red segment (80–100%)
      if (pct > 0.8) {
        ctx.beginPath();
        ctx.arc(cx, cy, r, yellowEnd, valueAngle, false);
        ctx.strokeStyle = '#f44336';
        ctx.lineWidth = lineWidth;
        ctx.lineCap = 'butt';
        ctx.stroke();
      }

      // Value text — centered, colored
      const color = pct <= 0.5 ? '#4caf50' : pct <= 0.8 ? '#ffeb3b' : '#f44336';
      const displayText = value.toFixed(1) + '%';
      const fSize = displayText.length > 6 ? 28 : 34;
      ctx.fillStyle = color;
      ctx.font = `bold ${fSize}px "Source Han Sans SC"`;
      ctx.textBaseline = 'middle';
      ctx.textAlign = 'center';
      ctx.fillText(displayText, cx, cy + 8);
    } else {
      ctx.fillStyle = '#666666';
      ctx.font = 'bold 28px "Source Han Sans SC"';
      ctx.textBaseline = 'middle';
      ctx.textAlign = 'center';
      ctx.fillText('N/A', cx, cy + 8);
    }

    // Label — bottom
    ctx.fillStyle = '#7ec8e3';
    ctx.font = 'bold 20px "Source Han Sans SC"';
    ctx.fillText('Copilot', cx, 165);

    this.$UD.setBaseDataIcon(this.context, canvas.toDataURL('image/png'));
  }

  getRefreshDuration() {
    switch (this.config.refreshRate) {
      case '1': return 1;
      case '2': return 2;
      case '3': return 5;
      case '4': return 10;
      case '5': return 30;
      case '6': return 60;
      default:  return 0;
    }
  }
}