import Component from '@/ecs/component.js';

class ItemProxy {
  constructor(Component, instance, slot) {
    this.Component = Component;
    this.instance = instance;
    this.slot = slot;
  }
  async load(source) {
    const {ecs} = this.Component;
    const json = await ecs.readJson(source);
    const scripts = {};
    if (json.projectionCheck) {
      scripts.projectionCheckInstance = await ecs.readScript(json.projectionCheck);
    }
    if (json.start) {
      scripts.startInstance = await ecs.readScript(json.start);
    }
    if (json.stop) {
      scripts.stopInstance = await ecs.readScript(json.stop);
    }
    this.json = json;
    this.scripts = scripts;
  }
  project(position, direction) {
    const {TileLayers} = this.Component.ecs.get(1);
    const layer = TileLayers.layer(0);
    const {projection} = this;
    if (!projection) {
      return undefined;
    }
    let startX = position.x;
    let startY = position.y;
    switch (direction) {
      case 0:
        startX += projection.distance[0];
        startY += projection.distance[1];
        break;
      case 1:
        startX -= projection.distance[1];
        startY += projection.distance[0];
        break;
      case 2:
        startX -= projection.distance[0];
        startY -= projection.distance[1];
        break;
      case 3:
        startX += projection.distance[1];
        startY -= projection.distance[0];
        break;
    }
    const projected = [];
    for (const row in projection.grid) {
      const columns = projection.grid[row];
      for (const column in columns) {
        const targeted = projection.grid[row][column];
        if (targeted) {
          let axe;
          switch (direction) {
            case 0:
              axe = [-row, column];
              break;
            case 1:
              axe = [-column, -row];
              break;
            case 2:
              axe = [row, -column];
              break;
            case 3:
              axe = [column, row];
              break;
          }
          const x = startX + parseInt(axe[0]);
          const y = startY + parseInt(axe[1]);
          if (x < 0 || y < 0 || x >= layer.area.x || y >= layer.area.y) {
            continue;
          }
          projected.push({x, y});
        }
      }
    }
    if (this.scripts.projectionCheckInstance) {
      this.scripts.projectionCheckInstance.context.ecs = this.Component.ecs;
      this.scripts.projectionCheckInstance.context.projected = projected;
      return this.scripts.projectionCheckInstance.evaluate();
    }
    else {
      return projected;
    }
  }
  get icon() {
    return this.json.icon;
  }
  get label() {
    return this.json.label;
  }
  get projection() {
    return this.json.projection;
  }
  get qty() {
    return this.instance.slots[this.slot].qty;
  }
  set qty(qty) {
    const {instance} = this;
    if (qty <= 0) {
      this.Component.markChange(instance.entity, 'cleared', {[this.slot]: true});
      delete instance.slots[this.slot];
      delete instance.$$items[this.slot];
    }
    else {
      instance.slots[this.slot].qty = qty;
      this.Component.markChange(instance.entity, 'qtyUpdated', {[this.slot]: qty});
    }
  }
}

export default class Inventory extends Component {
  async updateMany(entities) {
    for (const [id, {cleared, given, qtyUpdated, swapped}] of entities) {
      const instance = this.get(id);
      const {$$items, slots} = instance;
      if (cleared) {
        for (const slot in cleared) {
          delete slots[slot];
        }
      }
      if (given) {
        for (const slot in given) {
          $$items[slot] = new ItemProxy(this, instance, slot);
          await $$items[slot].load(given[slot].source);
          slots[slot] = given[slot];
        }
      }
      if (qtyUpdated) {
        for (const slot in qtyUpdated) {
          slots[slot].qty = qtyUpdated[slot];
        }
      }
      if (swapped) {
        for (const [l, otherEntityId, r] of swapped) {
          const otherInstance = this.get(otherEntityId);
          const {$$items: $$otherItems, slots: otherSlots} = otherInstance;
          const tmp = [$$items[l], slots[l]];
          [$$items[l], slots[l]] = [$$otherItems[r], otherSlots[r]];
          [$$otherItems[r], otherSlots[r]] = tmp;
          if ($$otherItems[r]) {
            $$otherItems[r].slot = r;
          }
          if ($$items[l]) {
            $$items[l].slot = l;
          }
        }
      }
    }
    await super.updateMany(entities);
    for (const [id, {slots}] of entities) {
      if (slots) {
        const instance = this.get(id);
        instance.$$items = {};
        for (const slot in slots) {
          instance.$$items[slot] = new ItemProxy(this, instance, slot);
          await instance.$$items[slot].load(instance.slots[slot].source);
        }
      }
    }
  }
  instanceFromSchema() {
    const Instance = super.instanceFromSchema();
    const Component = this;
    return class InventoryInstance extends Instance {
      $$items = {};
      item(slot) {
        return this.$$items[slot];
      }
      async give(stack) {
        const {slots} = this;
        for (let slot = 1; slot < 11; ++slot) {
          if (slots[slot]?.source === stack.source) {
            slots[slot].qty += stack.qty;
            Component.markChange(this.entity, 'qtyUpdated', {[slot]: slots[slot].qty});
            return;
          }
        }
        for (let slot = 1; slot < 11; ++slot) {
          if (!slots[slot]) {
            slots[slot] = stack;
            this.$$items[slot] = new ItemProxy(Component, this, slot);
            await this.$$items[slot].load();
            Component.markChange(this.entity, 'given', {[slot]: slots[slot]});
            return;
          }
        }
      }
      swapSlots(l, OtherInventory, r) {
        const {$$items, slots} = this;
        const {$$items: $$otherItems, slots: otherSlots} = OtherInventory;
        const tmp = [$$items[l], slots[l]];
        [$$items[l], slots[l]] = [$$otherItems[r], otherSlots[r]];
        [$$otherItems[r], otherSlots[r]] = tmp;
        if (undefined === slots[l]) {
          delete slots[l];
        }
        if (undefined === otherSlots[r]) {
          delete otherSlots[r];
        }
        Component.markChange(this.entity, 'swapped', [[l, OtherInventory.entity, r]]);
        Component.markChange(OtherInventory.entity, 'swapped', [[r, this.entity, l]]);
      }
      toNet(recipient, data) {
        if (recipient.id !== this.entity && this !== recipient.Player.openInventory) {
          return {};
        }
        return super.toNet(data);
      }
    }
  }
  async load(instance) {
    for (const slot in instance.slots) {
      instance.$$items[slot] = new ItemProxy(this, instance, slot);
      await instance.$$items[slot].load(instance.slots[slot].source);
    }
  }
  mergeDiff(original, update) {
    const merged = {
      ...original,
      qtyUpdated: {
        ...original.qtyUpdated,
        ...update.qtyUpdated,
      },
      cleared: {
        ...original.cleared,
        ...update.cleared,
      },
      given: {
        ...original.given,
        ...update.given,
      },
      swapped: [
        ...(original.swapped || []),
        ...(update.swapped || []),
      ],
    };
    return merged;
  }
  static properties = {
    slots: {
      type: 'map',
      value: {
        type: 'object',
        properties: {
          quantity: {type: 'uint16'},
          source: {type: 'string'},
        },
      },
    },
  };
}