import { createSignal } from "solid-js";
import {
  MdCommanderCommand,
  CommanderEntry,
  CompletionItem,
} from "../types";
import { rollSimple } from "./useDiceRoller";

// ==================== 默认命令 ====================

export const defaultCommands: Record<string, MdCommanderCommand> = {
  help: {
    command: "help",
    description: "显示帮助信息或特定命令的帮助",
    parameters: [
      {
        name: "cmd",
        description: "要查询的命令名",
        type: "enum",
        values: [], // 运行时填充
        required: false,
      },
    ],
    handler: (args) => {
      const cmdName = args.params.cmd;
      if (cmdName) {
        return {
          message: `命令：${cmdName}\n描述：${defaultCommands[cmdName]?.description || "无描述"}`,
          type: "info",
        };
      }
      const cmdList = Object.keys(defaultCommands).join(", ");
      return {
        message: `可用命令：${cmdList}`,
        type: "info",
      };
    },
  },
  clear: {
    command: "clear",
    description: "清空命令历史",
    handler: () => ({
      message: "命令历史已清空",
      type: "success",
    }),
  },
  roll: {
    command: "roll",
    description: "掷骰子 - 支持骰池、修饰符和组合",
    parameters: [
      {
        name: "formula",
        description: "骰子公式，如 3d6+{d4,d8}kh2-5",
        type: "string",
        required: true,
      },
    ],
    handler: (args) => {
      const formula = args.params.formula || "1d6";
      const result = rollSimple(formula);
      return {
        message: result.text,
        isHtml: result.isHtml,
        type: result.text.startsWith("错误") ? "error" : "success",
      };
    },
  },
};

// ==================== 工具函数 ====================

export function parseInput(input: string, commands?: Record<string, MdCommanderCommand>): {
  command?: string;
  params: Record<string, string>;
  options: Record<string, string>;
  incompleteParam?: { index: number; value: string };
} {
  const result: {
    command?: string;
    params: Record<string, string>;
    options: Record<string, string>;
    incompleteParam?: { index: number; value: string };
  } = {
    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("--")) {
      // 选项 --key=value 或 --key value
      const eqIndex = part.indexOf("=");
      if (eqIndex !== -1) {
        const key = part.slice(2, eqIndex);
        const value = part.slice(eqIndex + 1);
        result.options[key] = value;
      } else {
        const key = part.slice(2);
        if (i + 1 < parts.length && !parts[i + 1].startsWith("-")) {
          result.options[key] = parts[i + 1];
          i++;
        } else {
          // 未完成的选项
        }
      }
    } else if (part.startsWith("-") && part.length === 2) {
      // 短选项 -k value
      const key = part.slice(1);
      if (i + 1 < parts.length && !parts[i + 1].startsWith("-")) {
        result.options[key] = parts[i + 1];
        i++;
      }
    } else {
      // 位置参数
      if (paramIndex < paramDefs.length) {
        const paramDef = paramDefs[paramIndex];
        result.params[paramDef.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("-")) {
      result.incompleteParam = {
        index: paramIndex,
        value: lastPart,
      };
    }
  }

  return result;
}

export function getCompletions(
  input: string,
  commands: Record<string, MdCommanderCommand>,
): CompletionItem[] {
  const trimmed = input.trim();

  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);

  if (!parsed.command || !commands[parsed.command]) {
    const commandCompletions = Object.values(commands)
      .filter((cmd) => cmd.command.startsWith(parsed.command || ""))
      .map((cmd) => ({
        label: cmd.command,
        type: "command" as "command",
        description: cmd.description,
        insertText: cmd.command,
      }));
    if (commandCompletions.length > 0) {
      return commandCompletions;
    }
  }

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

  // 检查是否需要参数补全
  const paramDefs = cmd.parameters || [];
  const usedParams = Object.keys(parsed.params);
  
  // 如果还有未填的参数，提供参数值补全
  if (paramDefs.length > usedParams.length) {
    const paramDef = paramDefs[usedParams.length];
    if (paramDef.type === "enum" && paramDef.values) {
      const currentValue = parsed.incompleteParam?.value || "";
      return paramDef.values
        .filter((v) => v.startsWith(currentValue))
        .map((v) => ({
          label: v,
          type: "value",
          description: paramDef.description,
          insertText: v,
        }));
    }
    // 其他类型的参数，显示提示
    if (parsed.incompleteParam) {
      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" ? "" : ""}`,
    }));
}

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";
    case "info":
    default:
      return "text-blue-600";
  }
}

// ==================== Commander Hook ====================

export interface UseCommanderReturn {
  inputValue: () => string;
  entries: () => CommanderEntry[];
  showCompletions: () => boolean;
  completions: () => CompletionItem[];
  selectedCompletion: () => number;
  isFocused: () => boolean;
  setInputValue: (v: string) => void;
  setEntries: (updater: (prev: CommanderEntry[]) => CommanderEntry[]) => void;
  setShowCompletions: (v: boolean) => void;
  setSelectedCompletion: (v: number | ((prev: number) => number)) => void;
  setIsFocused: (v: boolean) => void;
  handleCommand: () => void;
  updateCompletions: () => void;
  acceptCompletion: () => void;
  commands: Record<string, MdCommanderCommand>;
  historyIndex: () => number;
  setHistoryIndex: (v: number) => void;
  commandHistory: () => string[];
  navigateHistory: (direction: 'up' | 'down') => void;
}

export function useCommander(
  customCommands?: Record<string, MdCommanderCommand>,
): UseCommanderReturn {
  const [inputValue, setInputValue] = createSignal("");
  const [entries, setEntries] = createSignal<CommanderEntry[]>([]);
  const [showCompletions, setShowCompletions] = createSignal(false);
  const [completions, setCompletions] = createSignal<CompletionItem[]>([]);
  const [selectedCompletion, setSelectedCompletion] = createSignal(0);
  const [isFocused, setIsFocused] = createSignal(false);
  
  // 命令历史
  const [commandHistory, setCommandHistory] = createSignal<string[]>([]);
  const [historyIndex, setHistoryIndex] = createSignal(-1);

  const commands = { ...defaultCommands, ...customCommands };

  // 更新 help 命令的参数值
  if (commands.help?.parameters?.[0]) {
    commands.help.parameters[0].values = Object.keys(commands).filter(
      (k) => k !== "help",
    );
  }

  const handleCommand = () => {
    const input = inputValue().trim();
    if (!input) return;

    const parsed = parseInput(input, commands);
    const commandName = parsed.command;
    const cmd = commands[commandName!];

    let result: { message: string; type?: "success" | "error" | "warning" | "info"; isHtml?: boolean };

    if (!cmd) {
      result = { message: `未知命令：${commandName}`, type: "error" };
    } else if (cmd.handler) {
      try {
        result = cmd.handler({ params: parsed.params, options: parsed.options });
      } catch (e) {
        result = {
          message: `执行错误：${e instanceof Error ? e.message : String(e)}`,
          type: "error",
        };
      }
    } else {
      result = { message: `命令 ${commandName} 已执行（无处理器）`, type: "info" };
    }

    const newEntry: CommanderEntry = {
      id: Date.now().toString() + Math.random().toString(36).slice(2),
      command: input,
      args: parsed.options,
      result,
      timestamp: new Date(),
    };

    setEntries((prev) => [...prev, newEntry]);
    
    // 添加到命令历史
    setCommandHistory((prev) => [...prev, input]);
    setHistoryIndex(-1); // 重置历史索引
    
    setInputValue("");
    setShowCompletions(false);

    if (commandName === "clear") {
      setEntries([]);
    }
  };

  const updateCompletions = () => {
    const input = inputValue();
    const comps = getCompletions(input, commands);
    setCompletions(comps);
    setShowCompletions(comps.length > 0 && isFocused());
    setSelectedCompletion(0);
  };

  const acceptCompletion = () => {
    const idx = selectedCompletion();
    const comp = completions()[idx];
    if (!comp) return;

    const input = inputValue();
    const parsed = parseInput(input, commands);

    let newValue: string;
    if (comp.type === "command") {
      newValue = comp.insertText + " ";
    } else if (comp.type === "option") {
      const base = parsed.command || "";
      const existingOptions = Object.entries(parsed.options)
        .map(([k, v]) => `--${k}=${v}`)
        .join(" ");
      newValue = `${base} ${existingOptions}${existingOptions ? " " : ""}${comp.insertText}`;
    } else if (comp.type === "value") {
      // 参数值补全
      const cmd = parsed.command ? commands[parsed.command] : null;
      const paramDefs = cmd?.parameters || [];
      const usedParams = Object.keys(parsed.params);
      
      if (paramDefs.length > usedParams.length) {
        // 当前参数的补全
        const base = parsed.command || "";
        const existingParams = Object.values(parsed.params).join(" ");
        const existingOptions = Object.entries(parsed.options)
          .map(([k, v]) => `--${k}=${v}`)
          .join(" ");
        newValue = `${base} ${existingParams}${existingParams ? " " : ""}${comp.insertText}${existingOptions ? " " + existingOptions : ""}`;
      } else {
        newValue = input;
      }
    } else {
      newValue = input;
    }

    setInputValue(newValue.trim());
    setShowCompletions(false);
  };

  const navigateHistory = (direction: 'up' | 'down') => {
    const history = commandHistory();
    if (history.length === 0) return;

    let newIndex = historyIndex();
    if (direction === 'up') {
      // 向上浏览历史（更早的命令）
      if (newIndex < history.length - 1) {
        newIndex++;
      }
    } else {
      // 向下浏览历史（更新的命令）
      if (newIndex > 0) {
        newIndex--;
      } else {
        // 回到当前输入
        setInputValue("");
        setHistoryIndex(-1);
        return;
      }
    }

    setHistoryIndex(newIndex);
    // 从历史末尾获取命令（最新的在前）
    setInputValue(history[history.length - 1 - newIndex]);
  };

  return {
    inputValue,
    entries,
    showCompletions,
    completions,
    selectedCompletion,
    isFocused,
    setInputValue,
    setEntries,
    setShowCompletions,
    setSelectedCompletion,
    setIsFocused,
    handleCommand,
    updateCompletions,
    acceptCompletion,
    commands,
    historyIndex,
    setHistoryIndex,
    commandHistory,
    navigateHistory,
  };
}