/*
 * This file is part of Baritone.
 *
 * Baritone is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Baritone is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Baritone.  If not, see <https://www.gnu.org/licenses/>.
 */

package baritone.pathing.movement;

import baritone.Baritone;
import baritone.api.BaritoneAPI;
import baritone.api.IBaritone;
import baritone.api.pathing.movement.ActionCosts;
import baritone.api.pathing.movement.MovementStatus;
import baritone.api.utils.*;
import baritone.api.utils.input.Input;
import baritone.pathing.movement.MovementState.MovementTarget;
import baritone.utils.BlockStateInterface;
import baritone.utils.ToolSet;
import net.minecraft.block.*;
import net.minecraft.block.properties.PropertyBool;
import net.minecraft.block.state.IBlockState;
import net.minecraft.init.Blocks;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.RayTraceResult;
import net.minecraft.util.math.Vec3d;
import net.minecraft.world.IBlockAccess;

import java.util.Optional;

import static baritone.pathing.movement.Movement.HORIZONTALS_BUT_ALSO_DOWN_____SO_EVERY_DIRECTION_EXCEPT_UP;

/**
 * Static helpers for cost calculation
 *
 * @author leijurv
 */
public interface MovementHelper extends ActionCosts, Helper {

    static boolean avoidBreaking(BlockStateInterface bsi, int x, int y, int z, IBlockState state) {
        Block b = state.getBlock();
        return b == Blocks.ICE // ice becomes water, and water can mess up the path
                || b instanceof BlockSilverfish // obvious reasons
                // call context.get directly with x,y,z. no need to make 5 new BlockPos for no reason
                || avoidAdjacentBreaking(bsi, x, y + 1, z, true)
                || avoidAdjacentBreaking(bsi, x + 1, y, z, false)
                || avoidAdjacentBreaking(bsi, x - 1, y, z, false)
                || avoidAdjacentBreaking(bsi, x, y, z + 1, false)
                || avoidAdjacentBreaking(bsi, x, y, z - 1, false);
    }

    static boolean avoidAdjacentBreaking(BlockStateInterface bsi, int x, int y, int z, boolean directlyAbove) {
        // returns true if you should avoid breaking a block that's adjacent to this one (e.g. lava that will start flowing if you give it a path)
        // this is only called for north, south, east, west, and up. this is NOT called for down.
        // we assume that it's ALWAYS okay to break the block thats ABOVE liquid
        IBlockState state = bsi.get0(x, y, z);
        Block block = state.getBlock();
        if (!directlyAbove // it is fine to mine a block that has a falling block directly above, this (the cost of breaking the stacked fallings) is included in cost calculations
                // therefore if directlyAbove is true, we will actually ignore if this is falling
                && block instanceof BlockFalling // obviously, this check is only valid for falling blocks
                && Baritone.settings().avoidUpdatingFallingBlocks.value // and if the setting is enabled
                && BlockFalling.canFallThrough(bsi.get0(x, y - 1, z))) { // and if it would fall (i.e. it's unsupported)
            return true; // dont break a block that is adjacent to unsupported gravel because it can cause really weird stuff
        }
        return block instanceof BlockLiquid;
    }

    static boolean canWalkThrough(IPlayerContext ctx, BetterBlockPos pos) {
        return canWalkThrough(new BlockStateInterface(ctx), pos.x, pos.y, pos.z);
    }

    static boolean canWalkThrough(BlockStateInterface bsi, int x, int y, int z) {
        return canWalkThrough(bsi, x, y, z, bsi.get0(x, y, z));
    }

    static boolean canWalkThrough(BlockStateInterface bsi, int x, int y, int z, IBlockState state) {
        Block block = state.getBlock();
        if (block == Blocks.AIR) { // early return for most common case
            return true;
        }
        if (block == Blocks.FIRE || block == Blocks.TRIPWIRE || block == Blocks.WEB || block == Blocks.END_PORTAL || block == Blocks.COCOA || block instanceof BlockSkull || block instanceof BlockTrapDoor) {
            return false;
        }
        if (Baritone.settings().blocksToAvoid.value.contains(block)) {
            return false;
        }
        if (block instanceof BlockDoor || block instanceof BlockFenceGate) {
            // Because there's no nice method in vanilla to check if a door is openable or not, we just have to assume
            // that anything that isn't an iron door isn't openable, ignoring that some doors introduced in mods can't
            // be opened by just interacting.
            return block != Blocks.IRON_DOOR;
        }
        if (block == Blocks.CARPET) {
            return canWalkOn(bsi, x, y - 1, z);
        }
        if (block instanceof BlockSnow) {
            // we've already checked doors and fence gates
            // so the only remaining dynamic isPassables are snow and trapdoor
            // if they're cached as a top block, we don't know their metadata
            // default to true (mostly because it would otherwise make long distance pathing through snowy biomes impossible)
            if (!bsi.worldContainsLoadedChunk(x, z)) {
                return true;
            }
            // the check in BlockSnow.isPassable is layers < 5
            // while actually, we want < 3 because 3 or greater makes it impassable in a 2 high ceiling
            if (state.getValue(BlockSnow.LAYERS) >= 3) {
                return false;
            }
            // ok, it's low enough we could walk through it, but is it supported?
            return canWalkOn(bsi, x, y - 1, z);
        }
        if (isFlowing(x, y, z, state, bsi)) {
            return false; // Don't walk through flowing liquids
        }
        if (block instanceof BlockLiquid) {
            if (Baritone.settings().assumeWalkOnWater.value) {
                return false;
            }
            IBlockState up = bsi.get0(x, y + 1, z);
            if (up.getBlock() instanceof BlockLiquid || up.getBlock() instanceof BlockLilyPad) {
                return false;
            }
            return block == Blocks.WATER || block == Blocks.FLOWING_WATER;
        }

        return block.isPassable(bsi.access, bsi.isPassableBlockPos.setPos(x, y, z));
    }

    /**
     * canWalkThrough but also won't impede movement at all. so not including doors or fence gates (we'd have to right click),
     * not including water, and not including ladders or vines or cobwebs (they slow us down)
     *
     * @param context Calculation context to provide block state lookup
     * @param x       The block's x position
     * @param y       The block's y position
     * @param z       The block's z position
     * @return Whether or not the block at the specified position
     */
    static boolean fullyPassable(CalculationContext context, int x, int y, int z) {
        return fullyPassable(
                context.bsi.access,
                context.bsi.isPassableBlockPos.setPos(x, y, z),
                context.bsi.get0(x, y, z)
        );
    }

    static boolean fullyPassable(IPlayerContext ctx, BlockPos pos) {
        return fullyPassable(ctx.world(), pos, ctx.world().getBlockState(pos));
    }

    static boolean fullyPassable(IBlockAccess access, BlockPos pos, IBlockState state) {
        Block block = state.getBlock();
        if (block == Blocks.AIR) { // early return for most common case
            return true;
        }
        // exceptions - blocks that are isPassable true, but we can't actually jump through
        if (block == Blocks.FIRE
                || block == Blocks.TRIPWIRE
                || block == Blocks.WEB
                || block == Blocks.VINE
                || block == Blocks.LADDER
                || block == Blocks.COCOA
                || block instanceof BlockDoor
                || block instanceof BlockFenceGate
                || block instanceof BlockSnow
                || block instanceof BlockLiquid
                || block instanceof BlockTrapDoor
                || block instanceof BlockEndPortal
                || block instanceof BlockSkull) {
            return false;
        }
        // door, fence gate, liquid, trapdoor have been accounted for, nothing else uses the world or pos parameters
        return block.isPassable(access, pos);
    }

    static boolean isReplaceable(int x, int y, int z, IBlockState state, BlockStateInterface bsi) {
        // for MovementTraverse and MovementAscend
        // block double plant defaults to true when the block doesn't match, so don't need to check that case
        // all other overrides just return true or false
        // the only case to deal with is snow
        /*
         *  public boolean isReplaceable(IBlockAccess worldIn, BlockPos pos)
         *     {
         *         return ((Integer)worldIn.getBlockState(pos).getValue(LAYERS)).intValue() == 1;
         *     }
         */
        Block block = state.getBlock();
        if (block == Blocks.AIR || isWater(block)) {
            // early return for common cases hehe
            return true;
        }
        if (block instanceof BlockSnow) {
            // as before, default to true (mostly because it would otherwise make long distance pathing through snowy biomes impossible)
            if (!bsi.worldContainsLoadedChunk(x, z)) {
                return true;
            }
            return state.getValue(BlockSnow.LAYERS) == 1;
        }
        if (block instanceof BlockDoublePlant) {
            BlockDoublePlant.EnumPlantType kek = state.getValue(BlockDoublePlant.VARIANT);
            return kek == BlockDoublePlant.EnumPlantType.FERN || kek == BlockDoublePlant.EnumPlantType.GRASS;
        }
        return state.getMaterial().isReplaceable();
    }

    @Deprecated
    static boolean isReplacable(int x, int y, int z, IBlockState state, BlockStateInterface bsi) {
        return isReplaceable(x, y, z, state, bsi);
    }

    static boolean isDoorPassable(IPlayerContext ctx, BlockPos doorPos, BlockPos playerPos) {
        if (playerPos.equals(doorPos)) {
            return false;
        }

        IBlockState state = BlockStateInterface.get(ctx, doorPos);
        if (!(state.getBlock() instanceof BlockDoor)) {
            return true;
        }

        return isHorizontalBlockPassable(doorPos, state, playerPos, BlockDoor.OPEN);
    }

    static boolean isGatePassable(IPlayerContext ctx, BlockPos gatePos, BlockPos playerPos) {
        if (playerPos.equals(gatePos)) {
            return false;
        }

        IBlockState state = BlockStateInterface.get(ctx, gatePos);
        if (!(state.getBlock() instanceof BlockFenceGate)) {
            return true;
        }

        return state.getValue(BlockFenceGate.OPEN);
    }

    static boolean isHorizontalBlockPassable(BlockPos blockPos, IBlockState blockState, BlockPos playerPos, PropertyBool propertyOpen) {
        if (playerPos.equals(blockPos)) {
            return false;
        }

        EnumFacing.Axis facing = blockState.getValue(BlockHorizontal.FACING).getAxis();
        boolean open = blockState.getValue(propertyOpen);

        EnumFacing.Axis playerFacing;
        if (playerPos.north().equals(blockPos) || playerPos.south().equals(blockPos)) {
            playerFacing = EnumFacing.Axis.Z;
        } else if (playerPos.east().equals(blockPos) || playerPos.west().equals(blockPos)) {
            playerFacing = EnumFacing.Axis.X;
        } else {
            return true;
        }

        return (facing == playerFacing) == open;
    }

    static boolean avoidWalkingInto(Block block) {
        return block instanceof BlockLiquid
                || block == Blocks.MAGMA
                || block == Blocks.CACTUS
                || block == Blocks.FIRE
                || block == Blocks.END_PORTAL
                || block == Blocks.WEB;
    }

    /**
     * Can I walk on this block without anything weird happening like me falling
     * through? Includes water because we know that we automatically jump on
     * water
     *
     * @param bsi   Block state provider
     * @param x     The block's x position
     * @param y     The block's y position
     * @param z     The block's z position
     * @param state The state of the block at the specified location
     * @return Whether or not the specified block can be walked on
     */
    static boolean canWalkOn(BlockStateInterface bsi, int x, int y, int z, IBlockState state) {
        Block block = state.getBlock();
        if (block == Blocks.AIR || block == Blocks.MAGMA) {
            // early return for most common case (air)
            // plus magma, which is a normal cube but it hurts you
            return false;
        }
        if (state.isBlockNormalCube()) {
            return true;
        }
        if (block == Blocks.LADDER || (block == Blocks.VINE && Baritone.settings().allowVines.value)) { // TODO reconsider this
            return true;
        }
        if (block == Blocks.FARMLAND || block == Blocks.GRASS_PATH) {
            return true;
        }
        if (block == Blocks.ENDER_CHEST || block == Blocks.CHEST) {
            return true;
        }
        if (isWater(block)) {
            // since this is called literally millions of times per second, the benefit of not allocating millions of useless "pos.up()"
            // BlockPos s that we'd just garbage collect immediately is actually noticeable. I don't even think its a decrease in readability
            Block up = bsi.get0(x, y + 1, z).getBlock();
            if (up == Blocks.WATERLILY || up == Blocks.CARPET) {
                return true;
            }
            if (isFlowing(x, y, z, state, bsi) || block == Blocks.FLOWING_WATER) {
                // the only scenario in which we can walk on flowing water is if it's under still water with jesus off
                return isWater(up) && !Baritone.settings().assumeWalkOnWater.value;
            }
            // if assumeWalkOnWater is on, we can only walk on water if there isn't water above it
            // if assumeWalkOnWater is off, we can only walk on water if there is water above it
            return isWater(up) ^ Baritone.settings().assumeWalkOnWater.value;
        }
        if (Baritone.settings().assumeWalkOnLava.value && isLava(block) && !isFlowing(x, y, z, state, bsi)) {
            return true;
        }
        if (block == Blocks.GLASS || block == Blocks.STAINED_GLASS) {
            return true;
        }
        if (block instanceof BlockSlab) {
            if (!Baritone.settings().allowWalkOnBottomSlab.value) {
                if (((BlockSlab) block).isDouble()) {
                    return true;
                }
                return state.getValue(BlockSlab.HALF) != BlockSlab.EnumBlockHalf.BOTTOM;
            }
            return true;
        }
        return block instanceof BlockStairs;
    }

    static boolean canWalkOn(IPlayerContext ctx, BetterBlockPos pos, IBlockState state) {
        return canWalkOn(new BlockStateInterface(ctx), pos.x, pos.y, pos.z, state);
    }

    static boolean canWalkOn(IPlayerContext ctx, BlockPos pos) {
        return canWalkOn(new BlockStateInterface(ctx), pos.getX(), pos.getY(), pos.getZ());
    }

    static boolean canWalkOn(IPlayerContext ctx, BetterBlockPos pos) {
        return canWalkOn(new BlockStateInterface(ctx), pos.x, pos.y, pos.z);
    }

    static boolean canWalkOn(BlockStateInterface bsi, int x, int y, int z) {
        return canWalkOn(bsi, x, y, z, bsi.get0(x, y, z));
    }

    static boolean canPlaceAgainst(BlockStateInterface bsi, int x, int y, int z) {
        return canPlaceAgainst(bsi, x, y, z, bsi.get0(x, y, z));
    }

    static boolean canPlaceAgainst(BlockStateInterface bsi, BlockPos pos) {
        return canPlaceAgainst(bsi, pos.getX(), pos.getY(), pos.getZ());
    }

    static boolean canPlaceAgainst(IPlayerContext ctx, BlockPos pos) {
        return canPlaceAgainst(new BlockStateInterface(ctx), pos);
    }

    static boolean canPlaceAgainst(BlockStateInterface bsi, int x, int y, int z, IBlockState state) {
        // can we look at the center of a side face of this block and likely be able to place?
        // (thats how this check is used)
        // therefore dont include weird things that we technically could place against (like carpet) but practically can't
        return state.isBlockNormalCube() || state.isFullBlock() || state.getBlock() == Blocks.GLASS || state.getBlock() == Blocks.STAINED_GLASS;
    }

    static double getMiningDurationTicks(CalculationContext context, int x, int y, int z, boolean includeFalling) {
        return getMiningDurationTicks(context, x, y, z, context.get(x, y, z), includeFalling);
    }

    static double getMiningDurationTicks(CalculationContext context, int x, int y, int z, IBlockState state, boolean includeFalling) {
        Block block = state.getBlock();
        if (!canWalkThrough(context.bsi, x, y, z, state)) {
            if (block instanceof BlockLiquid) {
                return COST_INF;
            }
            double mult = context.breakCostMultiplierAt(x, y, z, state);
            if (mult >= COST_INF) {
                return COST_INF;
            }
            if (avoidBreaking(context.bsi, x, y, z, state)) {
                return COST_INF;
            }
            double strVsBlock = context.toolSet.getStrVsBlock(state);
            if (strVsBlock <= 0) {
                return COST_INF;
            }
            double result = 1 / strVsBlock;
            result += context.breakBlockAdditionalCost;
            result *= mult;
            if (includeFalling) {
                IBlockState above = context.get(x, y + 1, z);
                if (above.getBlock() instanceof BlockFalling) {
                    result += getMiningDurationTicks(context, x, y + 1, z, above, true);
                }
            }
            return result;
        }
        return 0; // we won't actually mine it, so don't check fallings above
    }

    static boolean isBottomSlab(IBlockState state) {
        return state.getBlock() instanceof BlockSlab
                && !((BlockSlab) state.getBlock()).isDouble()
                && state.getValue(BlockSlab.HALF) == BlockSlab.EnumBlockHalf.BOTTOM;
    }

    /**
     * AutoTool for a specific block
     *
     * @param ctx The player context
     * @param b   the blockstate to mine
     */
    static void switchToBestToolFor(IPlayerContext ctx, IBlockState b) {
        switchToBestToolFor(ctx, b, new ToolSet(ctx.player()), BaritoneAPI.getSettings().preferSilkTouch.value);
    }

    /**
     * AutoTool for a specific block with precomputed ToolSet data
     *
     * @param ctx The player context
     * @param b   the blockstate to mine
     * @param ts  previously calculated ToolSet
     */
    static void switchToBestToolFor(IPlayerContext ctx, IBlockState b, ToolSet ts, boolean preferSilkTouch) {
        ctx.player().inventory.currentItem = ts.getBestSlot(b.getBlock(), preferSilkTouch);
    }

    static void moveTowards(IPlayerContext ctx, MovementState state, BlockPos pos) {
        state.setTarget(new MovementTarget(
                new Rotation(RotationUtils.calcRotationFromVec3d(ctx.playerHead(),
                        VecUtils.getBlockPosCenter(pos),
                        ctx.playerRotations()).getYaw(), ctx.player().rotationPitch),
                false
        )).setInput(Input.MOVE_FORWARD, true);
    }

    /**
     * Returns whether or not the specified block is
     * water, regardless of whether or not it is flowing.
     *
     * @param b The block
     * @return Whether or not the block is water
     */
    static boolean isWater(Block b) {
        return b == Blocks.FLOWING_WATER || b == Blocks.WATER;
    }

    /**
     * Returns whether or not the block at the specified pos is
     * water, regardless of whether or not it is flowing.
     *
     * @param ctx The player context
     * @param bp  The block pos
     * @return Whether or not the block is water
     */
    static boolean isWater(IPlayerContext ctx, BlockPos bp) {
        return isWater(BlockStateInterface.getBlock(ctx, bp));
    }

    static boolean isLava(Block b) {
        return b == Blocks.FLOWING_LAVA || b == Blocks.LAVA;
    }

    /**
     * Returns whether or not the specified pos has a liquid
     *
     * @param ctx The player context
     * @param p   The pos
     * @return Whether or not the block is a liquid
     */
    static boolean isLiquid(IPlayerContext ctx, BlockPos p) {
        return BlockStateInterface.getBlock(ctx, p) instanceof BlockLiquid;
    }

    static boolean possiblyFlowing(IBlockState state) {
        // Will be IFluidState in 1.13
        return state.getBlock() instanceof BlockLiquid
                && state.getValue(BlockLiquid.LEVEL) != 0;
    }

    static boolean isFlowing(int x, int y, int z, IBlockState state, BlockStateInterface bsi) {
        if (!(state.getBlock() instanceof BlockLiquid)) {
            return false;
        }
        if (state.getValue(BlockLiquid.LEVEL) != 0) {
            return true;
        }
        return possiblyFlowing(bsi.get0(x + 1, y, z))
                || possiblyFlowing(bsi.get0(x - 1, y, z))
                || possiblyFlowing(bsi.get0(x, y, z + 1))
                || possiblyFlowing(bsi.get0(x, y, z - 1));
    }


    static PlaceResult attemptToPlaceABlock(MovementState state, IBaritone baritone, BlockPos placeAt, boolean preferDown) {
        IPlayerContext ctx = baritone.getPlayerContext();
        Optional<Rotation> direct = RotationUtils.reachable(ctx, placeAt); // we assume that if there is a block there, it must be replacable
        boolean found = false;
        if (direct.isPresent()) {
            state.setTarget(new MovementState.MovementTarget(direct.get(), true));
            found = true;
        }
        for (int i = 0; i < 5; i++) {
            BlockPos against1 = placeAt.offset(HORIZONTALS_BUT_ALSO_DOWN_____SO_EVERY_DIRECTION_EXCEPT_UP[i]);
            if (MovementHelper.canPlaceAgainst(ctx, against1)) {
                if (!((Baritone) baritone).getInventoryBehavior().selectThrowawayForLocation(false, placeAt.getX(), placeAt.getY(), placeAt.getZ())) { // get ready to place a throwaway block
                    Helper.HELPER.logDebug("bb pls get me some blocks. dirt, netherrack, cobble");
                    state.setStatus(MovementStatus.UNREACHABLE);
                    return PlaceResult.NO_OPTION;
                }
                double faceX = (placeAt.getX() + against1.getX() + 1.0D) * 0.5D;
                double faceY = (placeAt.getY() + against1.getY() + 0.5D) * 0.5D;
                double faceZ = (placeAt.getZ() + against1.getZ() + 1.0D) * 0.5D;
                Rotation place = RotationUtils.calcRotationFromVec3d(ctx.playerHead(), new Vec3d(faceX, faceY, faceZ), ctx.playerRotations());
                RayTraceResult res = RayTraceUtils.rayTraceTowards(ctx.player(), place, ctx.playerController().getBlockReachDistance());
                if (res != null && res.typeOfHit == RayTraceResult.Type.BLOCK && res.getBlockPos().equals(against1) && res.getBlockPos().offset(res.sideHit).equals(placeAt)) {
                    state.setTarget(new MovementState.MovementTarget(place, true));
                    found = true;

                    if (!preferDown) {
                        // if preferDown is true, we want the last option
                        // if preferDown is false, we want the first
                        break;
                    }
                }
            }
        }
        if (ctx.getSelectedBlock().isPresent()) {
            BlockPos selectedBlock = ctx.getSelectedBlock().get();
            EnumFacing side = ctx.objectMouseOver().sideHit;
            // only way for selectedBlock.equals(placeAt) to be true is if it's replacable
            if (selectedBlock.equals(placeAt) || (MovementHelper.canPlaceAgainst(ctx, selectedBlock) && selectedBlock.offset(side).equals(placeAt))) {
                ((Baritone) baritone).getInventoryBehavior().selectThrowawayForLocation(true, placeAt.getX(), placeAt.getY(), placeAt.getZ());
                return PlaceResult.READY_TO_PLACE;
            }
        }
        if (found) {
            ((Baritone) baritone).getInventoryBehavior().selectThrowawayForLocation(true, placeAt.getX(), placeAt.getY(), placeAt.getZ());
            return PlaceResult.ATTEMPTING;
        }
        return PlaceResult.NO_OPTION;
    }

    enum PlaceResult {
        READY_TO_PLACE, ATTEMPTING, NO_OPTION;
    }
}