// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;

import "cog/IGame.sol";
import "cog/IState.sol";
import "cog/IRule.sol";

import {Schema, Node, Kind} from "@ds/schema/Schema.sol";
import {Actions} from "@ds/actions/Actions.sol";
import {IZoneKind} from "@ds/ext/ZoneKind.sol";

using Schema for State;

contract ZoneRule is Rule {
    Game game;

    constructor(Game g) {
        game = g;
    }

    function reduce(State state, bytes calldata action, Context calldata ctx) public returns (State) {
        if (bytes4(action) == Actions.ZONE_USE.selector) {
            (bytes24 mobileUnitID, bytes memory payload) = abi.decode(action[4:], (bytes24, bytes));
            _useZone(state, mobileUnitID, payload, ctx);
        } else if (bytes4(action) == Actions.SET_DATA_ON_ZONE.selector) {
            (bytes24 zoneID, string memory key, bytes32 data) = abi.decode(action[4:], (bytes24, string, bytes32));
            _setDataOnZone(state, ctx, zoneID, key, data);
        }
        return state;
    }

    function _useZone(State state, bytes24 mobileUnit, bytes memory payload, Context calldata ctx) internal {
        // check player owns mobileUnit
        if (Node.Player(ctx.sender) != state.getOwner(mobileUnit)) {
            revert("MobileUnitNotOwnedByPlayer");
        }
        // get location
        bytes24 mobileUnitTile = state.getCurrentLocation(mobileUnit, ctx.clock);

        // get zone
        bytes24 zone = Node.Zone(state.getTileZone(mobileUnitTile));

        // get zone implementation
        IZoneKind zoneImplementation = IZoneKind(state.getImplementation(zone));
        // if no implementation set, then this is a no-op
        if (address(zoneImplementation) == address(0)) {
            return;
        }
        // call the implementation
        zoneImplementation.use(game, zone, mobileUnit, payload);
    }

    function _setDataOnZone(State state, Context calldata ctx, bytes24 zoneID, string memory key, bytes32 data)
        private
    {
        require(bytes4(zoneID) == Kind.Zone.selector, "invalid id");

        address zoneImplementation = state.getImplementation(zoneID);

        require(ctx.sender == zoneImplementation, "cannot set data on zone. Caller must be zone implemenation");

        state.setData(zoneID, key, data);
    }
}