package dev.lumareth.improvedAerodynamics.flight;

import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.entity.BlockEntity;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.properties.DirectionProperty;
import net.minecraft.world.level.block.state.properties.Property;

/**
 * The frame cursor aim steers in, in ship coordinates: forward is the boresight (what Warium's gun reticle points
 * along, from the HUD block in front of the seat, else the way the seat faces), up is the ship's up axis and right
 * completes it. Server and client both build it from the same block data, so a cursor sent as components in this
 * frame means the same on both.
 *
 * @param nodePos the Vehicle Control Node the seat is linked to
 */
public record AimBasis(BlockPos seatPos, BlockPos nodePos, double[] forward, double[] right, double[] up) {

    /**
     * @param entityPos block position of the seat entity. Warium's control seat block is at that position or just
     *                  below it.
     * @return null if there is no seat block linked to a control node there
     */
    public static AimBasis of(Level level, BlockPos entityPos) {
        for (BlockPos pos : new BlockPos[]{entityPos, entityPos.below()}) {
            BlockEntity seat = level.getBlockEntity(pos);
            if (seat == null || !seat.getPersistentData().contains("ControlX")) {
                continue;
            }
            CompoundTag tag = seat.getPersistentData();
            BlockPos nodePos = BlockPos.containing(tag.getDouble("ControlX"), tag.getDouble("ControlY"), tag.getDouble("ControlZ"));
            return new AimBasis(pos, nodePos, null, null, null).withAxes(level, pos, nodePos);
        }
        return null;
    }

    private AimBasis withAxes(Level level, BlockPos seatPos, BlockPos nodePos) {
        BlockState state = level.getBlockState(seatPos);
        Direction facing = Direction.NORTH;
        Property<?> property = state.getBlock().getStateDefinition().getProperty("facing");
        if (property instanceof DirectionProperty directionProperty) {
            facing = state.getValue(directionProperty);
        }
        double fx = facing.getStepX();
        double fy = facing.getStepY();
        double fz = facing.getStepZ();

        // Warium's gun reticle: the HUD block in front of the seat holds the aim vector of its guns
        BlockEntity hud = level.getBlockEntity(seatPos.relative(facing));
        if (hud != null && hud.getPersistentData().contains("Pitch")) {
            CompoundTag hudTag = hud.getPersistentData();
            double bx = hudTag.getDouble("X") + facing.getStepX();
            double by = hudTag.getDouble("Pitch");
            double bz = hudTag.getDouble("Z") + facing.getStepZ();
            if (bx * bx + by * by + bz * bz > 1.0E-6) {
                fx = bx;
                fy = by;
                fz = bz;
            }
        }
        double length = Math.sqrt(fx * fx + fy * fy + fz * fz);
        if (length < 1.0E-6) {
            fx = 0.0;
            fy = 0.0;
            fz = -1.0;
            length = 1.0;
        }
        fx /= length;
        fy /= length;
        fz /= length;

        // right = forward x up(0,1,0)
        double rx = -fz;
        double ry = 0.0;
        double rz = fx;
        double rl = Math.sqrt(rx * rx + rz * rz);
        if (rl < 1.0E-6) {
            rx = 1.0;
            rz = 0.0;
            rl = 1.0;
        }
        rx /= rl;
        rz /= rl;
        // up = right x forward
        double ux = ry * fz - rz * fy;
        double uy = rz * fx - rx * fz;
        double uz = rx * fy - ry * fx;
        return new AimBasis(seatPos, nodePos, new double[]{fx, fy, fz}, new double[]{rx, ry, rz}, new double[]{ux, uy, uz});
    }

    /** Ship-space direction of a cursor given by its components along forward, right and up. */
    public double[] toShip(double cf, double cr, double cu) {
        return new double[]{
                forward[0] * cf + right[0] * cr + up[0] * cu,
                forward[1] * cf + right[1] * cr + up[1] * cu,
                forward[2] * cf + right[2] * cr + up[2] * cu};
    }
}