import { randomUUID } from "node:crypto";

import { createDatabase, CharacterGardenDatabase } from "./db";
import type { Entity } from "./contracts/entity";
import type { Turn } from "./contracts/turn";
import type { WorldState } from "./contracts/world";
import { processTurn, ProcessTurnResponse } from "./turns/processTurn";

export interface AppSnapshot {
  worldState: WorldState;
  turns: Turn[];
}

export interface CharacterGardenApp {
  db: CharacterGardenDatabase;
  getSnapshot(): AppSnapshot;
  processTurn(rawText: string): ProcessTurnResponse;
  reset(): AppSnapshot;
}

function createSeedWorldState(): WorldState {
  const now = Date.now();

  const entities: Record<string, Entity> = {
    room_start: {
      id: "room_start",
      name: "Start Room",
      type: "room",
      attributes: {
        description: "A plain room with a locked door.",
      },
    },
    room_exit: {
      id: "room_exit",
      name: "Exit Room",
      type: "room",
      attributes: {
        description: "A simple room beyond the door.",
      },
    },
    player: {
      id: "player",
      name: "Player",
      type: "character",
      attributes: {
        location: "room_start",
        has_key_1: false,
      },
    },
    door_1: {
      id: "door_1",
      name: "Old Door",
      type: "door",
      attributes: {
        location: "room_start",
        openable: true,
        locked: true,
        requiredKey: "key_1",
        open: false,
      },
    },
    key_1: {
      id: "key_1",
      name: "Brass Key",
      type: "item",
      attributes: {
        location: "room_start",
        takeable: true,
      },
    },
  };

  return {
    id: randomUUID(),
    entities,
    metadata: {
      domain: "door_key_mvp",
      version: 1,
    },
    createdAt: now,
  };
}

function ensureSeedState(db: CharacterGardenDatabase): WorldState {
  db.init();

  const latest = db.getLatestWorldState();
  if (latest) {
    return latest;
  }

  const seed = createSeedWorldState();
  db.upsertEntities(Object.values(seed.entities));
  db.insertWorldState(null, seed);
  return seed;
}

export function createCharacterGardenApp(dbPath: string): CharacterGardenApp {
  const db = createDatabase({ dbPath });
  let worldState = ensureSeedState(db);

  return {
    db,

    getSnapshot() {
      return {
        worldState,
        turns: db.listTurns(),
      };
    },

    processTurn(rawText: string) {
      const result = processTurn(rawText, worldState, db);
      worldState = result.worldState;
      return result;
    },

    reset() {
      db.wipe();
      worldState = ensureSeedState(db);
      return {
        worldState,
        turns: db.listTurns(),
      };
    },
  };
}