/**
 * VCD 文件处理模块
 * 功能：VCD 文件信息获取和信号解析
 * 依赖：vscode, fs
 * 使用场景：波形查看器相关功能
 */
import * as vscode from "vscode";

export async function getVCDFileInfo(
  panel: vscode.WebviewPanel,
  vcdFilePath: string,
  containerId: string,
) {
  try {
    const fs = require("fs");

    if (!fs.existsSync(vcdFilePath)) {
      panel.webview.postMessage({
        command: "vcdInfo",
        containerId: containerId,
        vcdInfo: {
          signalCount: "N/A",
          timeRange: "N/A",
          fileSize: "N/A",
          error: "文件不存在",
        },
      });
      return;
    }

    const stats = fs.statSync(vcdFilePath);
    const fileSizeKB = stats.size / 1024;
    const fileSize =
      fileSizeKB < 1024
        ? `${fileSizeKB.toFixed(2)} KB`
        : `${(fileSizeKB / 1024).toFixed(2)} MB`;

    const content = fs.readFileSync(vcdFilePath, "utf-8");
    const varMatches = content.match(/\$var/g);
    const signalCount = varMatches ? varMatches.length : 0;

    let timeRange = "N/A";
    const timeMatch = content.match(/#(\d+)/g);
    if (timeMatch && timeMatch.length > 0) {
      const times = timeMatch.map((t: string) => parseInt(t.substring(1)));
      const minTime = Math.min(...times);
      const maxTime = Math.max(...times);
      timeRange = `${minTime} - ${maxTime}`;
    }

    const signals = parseVCDSignals(content, 3);

    panel.webview.postMessage({
      command: "vcdInfo",
      containerId: containerId,
      vcdInfo: {
        signalCount: signalCount.toString(),
        timeRange: timeRange,
        fileSize: fileSize,
        signals: signals,
      },
    });
  } catch (error) {
    console.error("获取 VCD 文件信息失败:", error);
    panel.webview.postMessage({
      command: "vcdInfo",
      containerId: containerId,
      vcdInfo: {
        signalCount: "N/A",
        timeRange: "N/A",
        fileSize: "N/A",
        error: error instanceof Error ? error.message : "未知错误",
      },
    });
  }
}

function parseVCDSignals(content: string, maxSignals: number = 3) {
  const signals: Array<{
    name: string;
    identifier: string;
    width: number;
    values: Array<{ time: number; value: string }>;
  }> = [];

  try {
    const varRegex = /\$var\s+(\w+)\s+(\d+)\s+(\S+)\s+([^\$]+?)\s+\$end/g;
    let match;
    const signalDefs: Array<{
      name: string;
      identifier: string;
      width: number;
    }> = [];

    while (
      (match = varRegex.exec(content)) !== null &&
      signalDefs.length < maxSignals
    ) {
      const width = parseInt(match[2]);
      const identifier = match[3];
      const name = match[4].trim();
      signalDefs.push({ name, identifier, width });
    }

    const dumpvarsIndex = content.indexOf("$dumpvars");
    if (dumpvarsIndex === -1) {
      return signals;
    }

    const dataSection = content.substring(dumpvarsIndex);

    for (const signalDef of signalDefs) {
      const values: Array<{ time: number; value: string }> = [];
      let currentTime = 0;
      const lines = dataSection.split("\n");

      for (const line of lines) {
        const trimmedLine = line.trim();

        if (trimmedLine.startsWith("#")) {
          currentTime = parseInt(trimmedLine.substring(1));
          continue;
        }

        if (signalDef.width === 1) {
          const singleBitMatch = trimmedLine.match(
            new RegExp(`^([01xz])${signalDef.identifier}$`),
          );
          if (singleBitMatch) {
            values.push({ time: currentTime, value: singleBitMatch[1] });
          }
        } else {
          const multiBitMatch = trimmedLine.match(
            new RegExp(`^b([01xz]+)\\s+${signalDef.identifier}$`),
          );
          if (multiBitMatch) {
            values.push({ time: currentTime, value: multiBitMatch[1] });
          }
        }

        if (values.length >= 50) {
          break;
        }
      }

      signals.push({
        name: signalDef.name,
        identifier: signalDef.identifier,
        width: signalDef.width,
        values: values,
      });
    }
  } catch (error) {
    console.error("解析 VCD 信号数据失败:", error);
  }

  return signals;
}