package com.ruoyi.ft546.protocol;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public final class Ft546SrgvCommandEncoder {
    public Ft546EncodedCommand encode(Ft546SrgvCommandIntent intent,
                                      Ft546DeviceProfile profile,
                                      Set<String> capabilities) {
        if (intent == null) {
            throw new IllegalArgumentException("intent must not be null");
        }
        if (profile == null) {
            throw new IllegalArgumentException("profile must not be null");
        }
        if (capabilities == null) {
            throw new IllegalArgumentException(
                    "capabilities must not be null");
        }
        int[] route = route(intent.getPathPoints());
        Integer stage = intent.getTwoStageNumber();
        if (stage == null) {
            if (!capabilities.contains("POINT_TO_POINT_COMMAND")) {
                throw new IllegalStateException(
                        "POINT_TO_POINT_COMMAND is not enabled");
            }
            return main(intent, profile, route);
        }
        if (!capabilities.contains("TWO_STAGE_ATOMIC_TASK")) {
            throw new IllegalStateException(
                    "TWO_STAGE_ATOMIC_TASK is not enabled");
        }
        if (stage.intValue() == 1) {
            return secondStageOne(intent, profile, route);
        }
        if (stage.intValue() == 2) {
            return secondStageTwo(intent, profile, route);
        }
        throw new IllegalArgumentException("stage must be 1 or 2");
    }

    private static Ft546EncodedCommand main(Ft546SrgvCommandIntent intent,
                                             Ft546DeviceProfile profile,
                                             int[] route) {
        List<Ft546RegisterWrite> writes =
                new ArrayList<Ft546RegisterWrite>();
        add(writes, profile, "path", Ft546RegisterWrite.DataType.INT32,
                false, route);
        add(writes, profile, "taskNo", Ft546RegisterWrite.DataType.INT32,
                false, intent.getTaskNo());
        add(writes, profile, "taskType", Ft546RegisterWrite.DataType.INT16,
                false, intent.getTaskType());
        add(writes, profile, "trigger", Ft546RegisterWrite.DataType.INT16,
                true, 1);
        if (intent.getTaskType() == 8) {
            if (intent.getCrossFloorTarget() == null) {
                throw new IllegalArgumentException(
                        "crossFloorTarget is required");
            }
            add(writes, profile, "crossFloorFlag",
                    Ft546RegisterWrite.DataType.INT16, false, 1);
            add(writes, profile, "crossFloorTarget",
                    Ft546RegisterWrite.DataType.INT16, false,
                    intent.getCrossFloorTarget());
        }
        return new Ft546EncodedCommand(intent, writes, 1);
    }

    private static Ft546EncodedCommand secondStageOne(
            Ft546SrgvCommandIntent intent, Ft546DeviceProfile profile,
            int[] route) {
        List<Ft546RegisterWrite> writes =
                new ArrayList<Ft546RegisterWrite>();
        add(writes, profile, "secondPath",
                Ft546RegisterWrite.DataType.INT32, false, route);
        add(writes, profile, "secondStageFlag",
                Ft546RegisterWrite.DataType.INT16, true, 1);
        add(writes, profile, "secondTaskType",
                Ft546RegisterWrite.DataType.INT16, false,
                intent.getTaskType());
        add(writes, profile, "secondTaskNo",
                Ft546RegisterWrite.DataType.INT32, false,
                intent.getTaskNo());
        return new Ft546EncodedCommand(intent, writes, 1);
    }

    private static Ft546EncodedCommand secondStageTwo(
            Ft546SrgvCommandIntent intent, Ft546DeviceProfile profile,
            int[] route) {
        List<Ft546RegisterWrite> writes =
                new ArrayList<Ft546RegisterWrite>();
        add(writes, profile, "secondPath",
                Ft546RegisterWrite.DataType.INT32, false, route);
        add(writes, profile, "secondStageFlag",
                Ft546RegisterWrite.DataType.INT16, true, 2);
        add(writes, profile, "secondComplete",
                Ft546RegisterWrite.DataType.INT16, false, 99);
        add(writes, profile, "secondTaskType",
                Ft546RegisterWrite.DataType.INT16, false, 9);
        add(writes, profile, "secondTaskNo",
                Ft546RegisterWrite.DataType.INT32, false,
                intent.getTaskNo());
        return new Ft546EncodedCommand(intent, writes, 2);
    }

    private static void add(List<Ft546RegisterWrite> writes,
                            Ft546DeviceProfile profile, String register,
                            Ft546RegisterWrite.DataType dataType,
                            boolean trigger, int... values) {
        List<Integer> boxed = new ArrayList<Integer>(values.length);
        for (int value : values) {
            if (dataType == Ft546RegisterWrite.DataType.INT16
                    && (value < Short.MIN_VALUE || value > Short.MAX_VALUE)) {
                throw new IllegalArgumentException(
                        register + " value is not an int16");
            }
            boxed.add(value);
        }
        writes.add(new Ft546RegisterWrite(register(profile, register),
                dataType, boxed, writes.size() + 1, trigger));
    }

    private static int[] route(List<Integer> points) {
        if (points.size() < 2 || points.size() > 8) {
            throw new IllegalArgumentException(
                    "legacy route must contain between 2 and 8 command points");
        }
        int[] result = new int[8];
        for (int index = 0; index < points.size(); index++) {
            Integer point = points.get(index);
            if (point == null || point.intValue() <= 0) {
                throw new IllegalArgumentException(
                        "route node must be positive");
            }
            if (point.intValue() > 999999) {
                throw new IllegalArgumentException(
                        "route node exceeds six digits");
            }
            result[index] = point.intValue();
        }
        return result;
    }

    private static String register(Ft546DeviceProfile profile, String name) {
        String address = profile.getRegisters().get(name);
        if (address == null || address.trim().isEmpty()) {
            throw new IllegalArgumentException(
                    "profile register is missing: " + name);
        }
        return address.trim();
    }
}