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

// ==================== 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",
    options: {
      cmd: {
        option: "cmd",
        description: "要查询的命令名",
        type: "enum",
        values: [], // 运行时填充
      },
    },
    handler: (args) => {
      if (args.cmd) {
        return {
          message: `命令：${args.cmd}\n描述：${defaultCommands[args.cmd]?.description || "无描述"}`,
          type: "info",
        };
      }
      const cmdList = Object.keys(defaultCommands).join(", ");
      return {
        message: `可用命令：${cmdList}`,
        type: "info",
      };
    },
  },
  clear: {
    command: "clear",
    description: "清空命令历史",
    handler: () => ({
      message: "命令历史已清空",
      type: "success",
    }),
  },
  roll: {
    command: "roll",
    description: "掷骰子",
    options: {
      formula: {
        option: "formula",
        description: "骰子公式，如 2d6+3",
        type: "string",
        required: true,
      },
    },
    handler: (args) => {
      const formula = args.formula || "1d6";
      const match = formula.match(/^(\d+)?d(\d+)([+-]\d+)?$/i);
      if (!match) {
        return { message: `无效的骰子公式：${formula}`, type: "error" };
      }
      const count = parseInt(match[1] || "1");
      const sides = parseInt(match[2]);
      const modifier = parseInt(match[3] || "0");
      const rolls: number[] = [];
      for (let i = 0; i < count; i++) {
        rolls.push(Math.floor(Math.random() * sides) + 1);
      }
      const total = rolls.reduce((a, b) => a + b, 0) + modifier;
      return {
        message: `${formula} = [${rolls.join(", ")}]${modifier !== 0 ? (modifier > 0 ? `+${modifier}` : modifier) : ""} = ${total}`,
        type: "success",
      };
    },
  },
};

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

export function parseInput(input: string): {
  command?: string;
  options: Record<string, string>;
  incompleteOption?: string;
} {
  const result: {
    command?: string;
    options: Record<string, string>;
    incompleteOption?: string;
  } = {
    options: {},
  };

  const trimmed = input.trim();
  if (!trimmed) return result;

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

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

  while (i < parts.length) {
    const part = parts[i];
    if (part.startsWith("--")) {
      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 {
          result.incompleteOption = key;
        }
      }
    }
    i++;
  }

  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);

  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",
        description: cmd.description,
        insertText: cmd.command,
      }));
    if (commandCompletions.length > 0) {
      return commandCompletions;
    }
  }

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

  if (parsed.incompleteOption) {
    const option = cmd.options[parsed.incompleteOption];
    if (option?.type === "enum" && option.values) {
      return option.values
        .filter((v) => v.startsWith(parsed.incompleteOption))
        .map((v) => ({
          label: v,
          type: "value",
          insertText: v,
        }));
    }
  }

  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>;
}

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);

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

  // 更新 help 命令的选项值
  if (commands.help?.options?.cmd) {
    commands.help.options.cmd.values = Object.keys(commands).filter(
      (k) => k !== "help",
    );
  }

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

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

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

    if (!cmd) {
      result = { message: `未知命令：${commandName}`, type: "error" };
    } else if (cmd.handler) {
      try {
        result = cmd.handler(parsed.options);
      } catch (e) {
        result = {
          message: `执行错误：${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]);
    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);

    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 ? " " : ""}${comp.insertText}`;
    } else {
      const optKey = parsed.incompleteOption;
      if (optKey) {
        const base = parsed.command || "";
        const otherOptions = Object.entries(parsed.options)
          .filter(([k]) => k !== optKey)
          .map(([k, v]) => `--${k}=${v}`)
          .join(" ");
        newValue = `${base} --${optKey}=${comp.insertText}${otherOptions ? " " + otherOptions : ""}`;
      } else {
        newValue = input;
      }
    }

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

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