import { createStore } from "solid-js/store";

export interface Pin {
  x: number;
  y: number;
  label: string;
}

interface PinsState {
  pins: Pin[];
  rawSrc: string;
  isFixed: boolean;
}

// 生成标签 A-Z, AA-ZZ, AAA-ZZZ ...
export function generateLabel(index: number): string {
  const labels: string[] = [];
  let num = index;

  do {
    const remainder = num % 26;
    labels.unshift(String.fromCharCode(65 + remainder));
    num = Math.floor(num / 26) - 1;
  } while (num >= 0);

  return labels.join('');
}

// 解析 pins 字符串 "A:30,40 B:10,30" -> Pin[]
export function parsePins(pinsStr: string): Pin[] {
  if (!pinsStr) return [];

  const pins: Pin[] = [];
  const regex = /([A-Z]+):(\d+),(\d+)/g;
  let match;

  while ((match = regex.exec(pinsStr)) !== null) {
    pins.push({
      label: match[1],
      x: parseInt(match[2]),
      y: parseInt(match[3])
    });
  }

  return pins;
}

// 格式化 pins 为字符串 "A:30,40 B:10,30"
export function formatPins(pins: Pin[]): string {
  return pins.map(pin => `${pin.label}:${pin.x},${pin.y}`).join(' ');
}

// 找到最早未使用的标签
export function findNextUnusedLabel(pins: Pin[]): string {
  const usedLabels = new Set(pins.map(p => p.label));

  let index = 0;
  while (true) {
    const label = generateLabel(index);
    if (!usedLabels.has(label)) {
      return label;
    }
    index++;
    if (index > 10000) break; // 安全限制
  }

  return generateLabel(pins.length);
}

// 创建 store 实例
export function createPinsStore(initialPinsStr: string = "", initialFixed: boolean = false) {
  const [state, setState] = createStore<PinsState>({
    pins: parsePins(initialPinsStr),
    rawSrc: "",
    isFixed: initialFixed
  });

  const setRawSrc = (src: string) => {
    setState("rawSrc", src);
  };

  const addPin = (x: number, y: number) => {
    const label = findNextUnusedLabel(state.pins);
    setState("pins", [...state.pins, { x, y, label }]);
  };

  const removePin = (index: number) => {
    setState("pins", state.pins.filter((_, i) => i !== index));
  };

  const formatCurrentPins = () => formatPins(state.pins);

  const getCopyText = () => {
    const pinsStr = formatCurrentPins();
    return `:md-pins[${state.rawSrc}]{pins="${pinsStr}" fixed}`;
  };

  return {
    state,
    setState,
    setRawSrc,
    addPin,
    removePin,
    formatCurrentPins,
    getCopyText
  };
}