import { AutocompleteInteraction } from "discord.js";
import { resolveUser } from "@systems/users";
import { getCharacters, getCharacterByName } from "@systems/characters";
import { getPersistentPreference, getSessionBorrow } from "@systems/borrow";
import { cfg } from "@systems/config";
import fs from "fs";
import path from "path";

// ─── Autocomplete subsets ─────────────────────────────────────────────────────

// Character names — own chars + shared chars accessible to this user
async function autocompleteCharNames(
  interaction: AutocompleteInteraction,
  focused: string
): Promise<void> {
  const member = await interaction.guild!.members.fetch(interaction.user.id);
  const user   = await resolveUser(member);
  if (!user.userKey) return interaction.respond([]);

  const ownChars = getCharacters(user.userKey).map((c) => ({
    name:  `${c.class} ${c.level} ${c.name}`,
    value: c.name,
  }));

  // Include shared chars (scan all users' sharedWith arrays)
  const sharedChars: { name: string; value: string }[] = [];
  try {
    const chars = JSON.parse(
      fs.readFileSync(path.join(__dirname, "../../data/characters.json"), "utf8")
    );
    for (const [ownerKey, data] of Object.entries(chars) as [string, any][]) {
      if (ownerKey === user.userKey) continue;
      for (const char of data.characters ?? []) {
        if (char.sharedWith?.includes(user.userKey)) {
          sharedChars.push({
            name:  `${char.class} ${char.level} ${char.name} (shared by ${ownerKey})`,
            value: char.name,
          });
        }
      }
    }
  } catch {}

  const all = [...ownChars, ...sharedChars]
    .filter((c) => c.name.toLowerCase().includes(focused.toLowerCase()))
    .slice(0, 25);

  await interaction.respond(all);
}

// Usermap keys — all registered users (officer commands)
async function autocompleteUserKeys(
  interaction: AutocompleteInteraction,
  focused: string
): Promise<void> {
  try {
    const usermap = JSON.parse(
      fs.readFileSync(path.join(__dirname, "../../data/usermap.json"), "utf8")
    );
    const choices = Object.entries(usermap)
      .map(([, entry]: [string, any]) => {
        const fileKey = typeof entry === "string" ? entry : entry.file;
        const alias   = typeof entry === "object" ? (entry.aliases?.[0] ?? fileKey) : fileKey;
        return { name: `${alias} (${fileKey})`, value: fileKey };
      })
      .filter((c) => c.name.toLowerCase().includes(focused.toLowerCase()))
      .slice(0, 25);
    await interaction.respond(choices);
  } catch {
    await interaction.respond([]);
  }
}

// TG slots — active slot hours
async function autocompleteSlots(
  interaction: AutocompleteInteraction,
  focused: string
): Promise<void> {
  const slots = cfg("slots")
    .filter((s) => s.active)
    .map((s) => ({ name: `${s.tgHour}:00`, value: String(s.tgHour) }))
    .filter((s) => s.name.includes(focused));
  await interaction.respond(slots);
}

// ─── Router ───────────────────────────────────────────────────────────────────

export async function handleAutocomplete(interaction: AutocompleteInteraction): Promise<void> {
  try {
    const focused     = interaction.options.getFocused(true);
    const optionName  = focused.name;
    const focusedValue = focused.value as string;

    // Route by option name
    if (optionName === "char_name") {
      return await autocompleteCharNames(interaction, focusedValue);
    }
    if (optionName === "name") {
      // Officer user key args
      return await autocompleteUserKeys(interaction, focusedValue);
    }
    if (optionName === "slot") {
      return await autocompleteSlots(interaction, focusedValue);
    }

    await interaction.respond([]);
  } catch (err) {
    console.error("[autocomplete] error:", err);
    try { await interaction.respond([]); } catch {}
  }
}