import type { MdCommanderCommandMap, CompletionItem } from "../types";

export interface ParsedCommand {
  command?: string;
  params: Record<string, string>;
  options: Record<string, string>;
  incompleteParam?: { index: number; value: string };
}

/**
 * 解析命令行输入
 */
export function parseInput(input: string, commands?: MdCommanderCommandMap): ParsedCommand {
  const result: ParsedCommand = { params: {}, options: {} };
  const trimmed = input.trim();
  if (!trimmed) return result;

  const parts = trimmed.split(/\s+/);
  let i = 0;

  // 获取命令
  if (parts[0] && !parts[0].startsWith("-")) {
    result.command = parts[0];
    i = 1;
  }

  // 获取命令的参数定义
  const cmd = result.command ? commands?.[result.command] : undefined;
  const paramDefs = cmd?.parameters || [];
  let paramIndex = 0;

  // 解析参数和选项
  while (i < parts.length) {
    const part = parts[i];

    if (part.startsWith("--")) {
      const eqIndex = part.indexOf("=");
      if (eqIndex !== -1) {
        result.options[part.slice(2, eqIndex)] = part.slice(eqIndex + 1);
      } else {
        const key = part.slice(2);
        if (i + 1 < parts.length && !parts[i + 1].startsWith("-")) {
          result.options[key] = parts[i + 1];
          i++;
        }
      }
    } else if (part.startsWith("-") && part.length === 2) {
      const key = part.slice(1);
      if (i + 1 < parts.length && !parts[i + 1].startsWith("-")) {
        result.options[key] = parts[i + 1];
        i++;
      }
    } else if (paramIndex < paramDefs.length) {
      result.params[paramDefs[paramIndex].name] = part;
      paramIndex++;
    }
    i++;
  }

  // 检查是否有未完成的位置参数
  if (paramIndex < paramDefs.length) {
    const lastPart = parts[parts.length - 1];
    if (lastPart && !lastPart.startsWith("-") && parts.length > 1) {
      result.incompleteParam = { index: paramIndex, value: lastPart };
    }
  }

  return result;
}

/**
 * 获取自动补全建议
 */
export function getCompletions(input: string, commands: MdCommanderCommandMap): CompletionItem[] {
  const trimmed = input.trim();

  // 空输入时返回所有命令
  if (!trimmed || /^\s*$/.test(trimmed)) {
    return Object.values(commands).map((cmd) => ({
      label: cmd.command,
      type: "command",
      description: cmd.description,
      insertText: cmd.command,
    }));
  }

  const parsed = parseInput(trimmed, commands);

  // 命令补全
  if (!parsed.command || !commands[parsed.command]) {
    return Object.values(commands)
      .filter((cmd) => cmd.command.startsWith(parsed.command || ""))
      .map((cmd) => ({
        label: cmd.command,
        type: "command",
        description: cmd.description,
        insertText: cmd.command,
      }));
  }

  const cmd = commands[parsed.command];
  if (!cmd) return [];

  const paramDefs = cmd.parameters || [];
  const usedParams = Object.keys(parsed.params);

  // 判断是否正在输入最后一个参数
  const isTypingLastParam = paramDefs.length === usedParams.length &&
    trimmed.length > 0 &&
    !trimmed.endsWith(" ") &&
    !trimmed.split(/\s+/)[trimmed.split(/\s+/).length - 1].startsWith("-");

  // 参数补全
  if (paramDefs.length > usedParams.length || parsed.incompleteParam || isTypingLastParam) {
    let paramIndex = parsed.incompleteParam?.index ?? (isTypingLastParam ? paramDefs.length - 1 : usedParams.length);
    const paramDef = paramDefs[paramIndex];
    if (!paramDef) return [];

    let currentValue = parsed.incompleteParam?.value || "";
    if (isTypingLastParam && !parsed.incompleteParam) {
      const parts = trimmed.split(/\s+/);
      currentValue = parts[parts.length - 1] || "";
    }

    // 模板补全
    if (paramDef.templates) {
      return paramDef.templates
        .filter((t) => t.label.toLowerCase().includes(currentValue.toLowerCase()))
        .map((t) => ({
          label: t.label,
          type: "value",
          description: t.description,
          insertText: t.insertText,
        }));
    }

    // 枚举补全
    if (paramDef.type === "enum" && paramDef.values) {
      return paramDef.values
        .filter((v) => v.startsWith(currentValue))
        .map((v) => ({
          label: v,
          type: "value",
          description: paramDef.description,
          insertText: v,
        }));
    }

    // 其他类型显示提示
    return [{
      label: `<${paramDef.name}>`,
      type: "value",
      description: `${paramDef.type}${paramDef.required !== false ? " (必填)" : ""}: ${paramDef.description || ""}`,
      insertText: "",
    }];
  }

  // 选项补全
  if (!cmd.options) return [];

  const usedOptions = Object.keys(parsed.options);
  return Object.values(cmd.options)
    .filter((opt) => !usedOptions.includes(opt.option))
    .map((opt) => ({
      label: `--${opt.option}`,
      type: "option",
      description: opt.description,
      insertText: `--${opt.option}=${opt.type === "boolean" ? "" : ""}`,
    }));
}

/**
 * 根据结果类型获取 CSS 类名
 */
export function getResultClass(type?: "success" | "error" | "warning" | "info"): string {
  switch (type) {
    case "success": return "text-green-600";
    case "error": return "text-red-600";
    case "warning": return "text-yellow-600";
    default: return "text-blue-600";
  }
}