import { logger } from '../util/logger.js';
import type { PostAction } from '../types.js';

const ROWS = 5;
const COLS = 12;

export interface PlacedItem {
  row: number;
  col: number;
  w: number;
  h: number;
  postAction: PostAction;
}

export class InventoryTracker {
  private grid: boolean[][];
  private items: PlacedItem[] = [];

  constructor() {
    this.grid = Array.from({ length: ROWS }, () => Array(COLS).fill(false));
  }

  /** Initialize from a grid scan result (occupied cells + detected items). */
  initFromScan(
    cells: boolean[][],
    items: { row: number; col: number; w: number; h: number }[],
    defaultAction: PostAction = 'stash',
  ): void {
    // Reset
    for (let r = 0; r < ROWS; r++) {
      this.grid[r].fill(false);
    }
    this.items = [];

    // Mark occupied cells from scan
    for (let r = 0; r < Math.min(cells.length, ROWS); r++) {
      for (let c = 0; c < Math.min(cells[r].length, COLS); c++) {
        this.grid[r][c] = cells[r][c];
      }
    }

    // Record detected items, filtering out impossibly large ones (max POE2 item = 2×4)
    for (const item of items) {
      if (item.w > 2 || item.h > 4) {
        logger.warn({ row: item.row, col: item.col, w: item.w, h: item.h }, 'Ignoring oversized item (false positive)');
        continue;
      }
      this.items.push({ row: item.row, col: item.col, w: item.w, h: item.h, postAction: defaultAction });
    }

    logger.info({ occupied: ROWS * COLS - this.freeCells, items: this.items.length, free: this.freeCells }, 'Inventory initialized from scan');
  }

  /** Try to place an item of size w×h. Column-first to match game's left-priority placement. */
  tryPlace(w: number, h: number, postAction: PostAction = 'stash'): { row: number; col: number } | null {
    for (let col = 0; col <= COLS - w; col++) {
      for (let row = 0; row <= ROWS - h; row++) {
        if (this.fits(row, col, w, h)) {
          this.place(row, col, w, h, postAction);
          logger.info({ row, col, w, h, postAction, free: this.freeCells }, 'Item placed in inventory');
          return { row, col };
        }
      }
    }
    return null;
  }

  /** Check if an item of size w×h can fit anywhere. */
  canFit(w: number, h: number): boolean {
    for (let col = 0; col <= COLS - w; col++) {
      for (let row = 0; row <= ROWS - h; row++) {
        if (this.fits(row, col, w, h)) return true;
      }
    }
    return false;
  }

  /** Get all placed items. */
  getItems(): PlacedItem[] {
    return [...this.items];
  }

  /** Get items with a specific postAction. */
  getItemsByAction(action: PostAction): PlacedItem[] {
    return this.items.filter(i => i.postAction === action);
  }

  /** Check if any items have a specific postAction. */
  hasItemsWithAction(action: PostAction): boolean {
    return this.items.some(i => i.postAction === action);
  }

  /** Remove a specific item from tracking and unmark its grid cells. */
  removeItem(item: PlacedItem): void {
    const idx = this.items.indexOf(item);
    if (idx === -1) return;
    // Unmark grid cells
    for (let r = item.row; r < item.row + item.h; r++) {
      for (let c = item.col; c < item.col + item.w; c++) {
        this.grid[r][c] = false;
      }
    }
    this.items.splice(idx, 1);
  }

  /** Remove all items with a specific postAction. */
  removeItemsByAction(action: PostAction): void {
    const toRemove = this.items.filter(i => i.postAction === action);
    for (const item of toRemove) {
      this.removeItem(item);
    }
    logger.info({ action, removed: toRemove.length, remaining: this.items.length }, 'Removed items by action');
  }

  /** Get a copy of the occupancy grid. */
  getGrid(): boolean[][] {
    return this.grid.map(row => [...row]);
  }

  /** Clear entire grid. */
  clear(): void {
    for (let r = 0; r < ROWS; r++) {
      this.grid[r].fill(false);
    }
    this.items = [];
    logger.info('Inventory cleared');
  }

  /** Get remaining free cells count. */
  get freeCells(): number {
    let count = 0;
    for (let r = 0; r < ROWS; r++) {
      for (let c = 0; c < COLS; c++) {
        if (!this.grid[r][c]) count++;
      }
    }
    return count;
  }

  private fits(row: number, col: number, w: number, h: number): boolean {
    for (let r = row; r < row + h; r++) {
      for (let c = col; c < col + w; c++) {
        if (this.grid[r][c]) return false;
      }
    }
    return true;
  }

  private place(row: number, col: number, w: number, h: number, postAction: PostAction): void {
    for (let r = row; r < row + h; r++) {
      for (let c = col; c < col + w; c++) {
        this.grid[r][c] = true;
      }
    }
    this.items.push({ row, col, w, h, postAction });
  }
}