/**
 * Command parser — parse a raw input string into a typed ParsedInput.
 *
 * Pure function with no component dependencies, so it can live in its own
 * module and keep JournalInput small.
 */

import type { IconTypes } from "solid-icons";

export interface CompletionItem {
  label: string;
  kind: "command" | "value" | "no-results";
  insertText: string;
  /** Optional icon rendered before the label in the completions dropdown. */
  icon?: IconTypes;
}

export interface ParsedInput {
  type: "chat" | "roll" | "link" | "set" | "rolltag";
  payload: Record<string, unknown>;
  error?: string;
}

export function parseInput(raw: string): ParsedInput {
  if (raw.startsWith("/roll ")) {
    const arg = raw.slice("/roll ".length).trim();
    if (!arg)
      return { type: "roll", payload: {}, error: "需要骰子表达式或种子表键名" };
    return { type: "roll", payload: { arg } };
  }

  if (raw.startsWith("/link ")) {
    const arg = raw.slice("/link ".length).trim();
    if (!arg) return { type: "link", payload: {}, error: "需要路径" };
    const hashIdx = arg.indexOf("#");
    const path = hashIdx === -1 ? arg : arg.slice(0, hashIdx);
    const section =
      hashIdx === -1 ? undefined : arg.slice(hashIdx + 1) || undefined;
    return { type: "link", payload: { path, section } };
  }

  if (raw.startsWith("/set ")) {
    const rest = raw.slice("/set ".length).trim();
    if (!rest)
      return { type: "set", payload: {}, error: "格式: /set $key expression" };

    // Split on first space to get key and expression
    const spaceIdx = rest.indexOf(" ");
    if (spaceIdx === -1)
      return { type: "set", payload: {}, error: "格式: /set $key expression" };

    const key = rest.slice(0, spaceIdx).trim();
    const expr = rest.slice(spaceIdx + 1).trim();

    if (!key || !expr)
      return { type: "set", payload: {}, error: "key 和 expression 不能为空" };

    if (!key.startsWith("$"))
      return { type: "set", payload: {}, error: "key 必须以 $ 开头" };

    // Check if expr is a rolltag (e.g. #w|#d|#s)
    if (expr.includes("|") && expr.split("|").every((t) => t.trim().startsWith("#"))) {
      const tags = expr.split("|").map((t) => t.trim());
      return { type: "rolltag", payload: { key, tags } };
    }

    return { type: "set", payload: { key, expr } };
  }

  if (raw === "/roll" || raw === "/link" || raw === "/set") {
    return { type: "chat", payload: {}, error: "请补全命令" };
  }

  return { type: "chat", payload: { text: raw } };
}