package com.javispedro.vndroid;

import android.os.Bundle;
import android.util.Log;
import android.view.accessibility.AccessibilityNodeInfo;

import androidx.annotation.Nullable;

import com.javispedro.vndroid.keymaps.KeyActionHandler;
import com.javispedro.vndroid.keymaps.KeyHandler;

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

public class KeyEventOutput implements KeyActionHandler {
    private final String TAG = KeyEventOutput.class.getSimpleName();

    private final List<KeyHandler> handlers = new ArrayList<KeyHandler>();

    @Nullable
    private AccessibilityNodeInfo getFocusNode() {
        ControlService service = ControlService.getInstance();
        if (service != null) {
            return service.findFocus(AccessibilityNodeInfo.FOCUS_INPUT);
        }
        return null;
    }

    public void addHandler(KeyHandler handler) {
        handler.setActionHandler(this);
        handlers.add(handler);
    }

    public void postKeyEvent(int key, boolean state) {
        if (state) Log.d(TAG, "keysym pressed: " + Integer.toHexString(key));
        for (KeyHandler handler : handlers) {
            boolean handled;
            if (state) {
                handled = handler.keyDown(key);
            } else {
                handled = handler.keyUp(key);
            }
            if (handled) {
                break;
            }
        }
    }

    @Override
    public void postText(CharSequence text) {
        AccessibilityNodeInfo node = getFocusNode();
        if (node == null || !node.isEditable()) {
            Log.d(TAG, "no input focus or not editable");
            return;
        }

        final CharSequence curText = node.getText();
        final int curTextLen = curText != null ? curText.length() : 0;
        final int textLen = text.length();
        int selStart = node.getTextSelectionStart();
        int selEnd = node.getTextSelectionEnd();
        StringBuilder builder = new StringBuilder(curTextLen + textLen);

        Log.d(TAG, " cur text: " + curText + " start=" + selStart + " end=" + selEnd);

        if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
            // No selection, no cursor
            if (curTextLen > 0) builder.append(curText);
            builder.append(text);
        } else {
            builder.append(curText.subSequence(0, selStart));
            builder.append(text);
            builder.append(curText.subSequence(selEnd, curText.length()));

            selStart = selEnd + textLen;
            selEnd = selStart;
        }

        Log.d(TAG, " new text: " + builder.toString() + " start=" + selStart + " end=" + selEnd);

        Bundle args = new Bundle();
        args.putCharSequence(AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE,
                builder.toString());
        node.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, args);

        if (selStart != -1 && selEnd != -1 && selStart != builder.length()) {
            args = new Bundle();
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_START_INT, selStart);
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_END_INT, selEnd);
            node.performAction(AccessibilityNodeInfo.ACTION_SET_SELECTION, args);
        }
    }

    @Override
    public void postChar(char c) {
        AccessibilityNodeInfo node = getFocusNode();
        if (node == null || !node.isEditable()) {
            Log.d(TAG, "no input focus or not editable");
            return;
        }

        final CharSequence curText = node.getText();
        final int curTextLen = curText != null ? curText.length() : 0;
        int selStart = node.getTextSelectionStart();
        int selEnd = node.getTextSelectionEnd();
        StringBuilder builder = new StringBuilder(curTextLen + 1);

        Log.d(TAG, " cur text: " + curText + " start=" + selStart + " end=" + selEnd);

        if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
            // No selection, no cursor
            if (curTextLen > 0) builder.append(curText);
            builder.append(c);
        } else {
            builder.append(curText.subSequence(0, selStart));
            builder.append(c);
            builder.append(curText.subSequence(selEnd, curText.length()));

            selStart = selEnd + 1;
            selEnd = selStart;
        }

        Log.d(TAG, " new text: " + builder.toString() + " start=" + selStart + " end=" + selEnd);

        Bundle args = new Bundle();
        args.putCharSequence(AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE,
                builder.toString());
        node.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, args);

        if (selStart != -1 && selEnd != -1 && selStart != builder.length()) {
            args = new Bundle();
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_START_INT, selStart);
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_END_INT, selEnd);
            node.performAction(AccessibilityNodeInfo.ACTION_SET_SELECTION, args);
        }
    }

    @Override
    public void postLocalAction(int action) {
        AccessibilityNodeInfo node = getFocusNode();
        if (node == null || !node.isEditable()) {
            Log.d(TAG, "no input focus or not editable");
            return;
        }

        final CharSequence curText = node.getText();
        final int curTextLen = curText != null ? curText.length() : 0;
        int selStart = node.getTextSelectionStart();
        int selEnd = node.getTextSelectionEnd();
        StringBuilder builder = null;

        Log.d(TAG, " cur text: " + curText + " start=" + selStart + " end=" + selEnd);

        switch (action) {
            case KeyActionHandler.ACTION_BACKSPACE:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                builder = new StringBuilder(curTextLen - 1);
                if (selStart == selEnd && selStart > 0) {
                    builder.append(curText.subSequence(0, selStart - 1));
                    builder.append(curText.subSequence(selEnd, curTextLen));
                    selStart = selStart - 1;
                    selEnd = selStart;
                } else if (selStart != selEnd) {
                    builder.append(curText.subSequence(0, selStart));
                    builder.append(curText.subSequence(selEnd, curTextLen));
                    selEnd = selStart;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_DEL:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                builder = new StringBuilder(curTextLen - 1);
                if (selStart == selEnd && selStart < curTextLen) {
                    builder.append(curText.subSequence(0, selStart));
                    builder.append(curText.subSequence(selEnd + 1, curTextLen));
                    selStart = selStart;
                    selEnd = selStart;
                } else if (selStart != selEnd) {
                    builder.append(curText.subSequence(0, selStart));
                    builder.append(curText.subSequence(selEnd, curTextLen));
                    selEnd = selStart;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_MOVE_LEFT:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                if (selStart > 0) {
                    selStart = selStart - 1;
                    selEnd = selStart;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_MOVE_RIGHT:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                if (selEnd < curTextLen) {
                    selStart = selEnd + 1;
                    selEnd = selStart;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_MOVE_LEFTMOST:
                selStart = 0;
                selEnd = 0;
                break;
            case KeyActionHandler.ACTION_MOVE_RIGHTMOST:
                if (curTextLen == 0) {
                    return;
                }
                selStart = curTextLen;
                selEnd = curTextLen;
                break;
            case KeyActionHandler.ACTION_SELECT_LEFT:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                if (selStart > 0) {
                    selStart = selStart - 1;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_SELECT_RIGHT:
                if (selStart == -1 || selEnd == -1 || curTextLen == 0) {
                    return;
                }
                if (selEnd < curTextLen) {
                    selEnd = selEnd + 1;
                } else {
                    return;
                }
                break;
            case KeyActionHandler.ACTION_SELECT_LEFTMOST:
                selStart = 0;
                break;
            case KeyActionHandler.ACTION_SELECT_RIGHTMOST:
                if (curTextLen == 0) {
                    return;
                }
                selEnd = curTextLen;
                break;
            default:
                return;
        }

        if (builder != null) {
            Log.d(TAG, " new text: " + builder.toString() + " start=" + selStart + " end=" + selEnd);
        } else {
            Log.d(TAG, " new  start=" + selStart + " end=" + selEnd);
        }

        if (builder != null && builder.toString() != curText) {
            Bundle args = new Bundle();
            args.putCharSequence(AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE,
                    builder.toString());
            node.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, args);
        }

        if (selStart != -1 && selEnd != -1 && (builder == null || selStart != builder.length())) {
            Bundle args = new Bundle();
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_START_INT, selStart);
            args.putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_END_INT, selEnd);
            node.performAction(AccessibilityNodeInfo.ACTION_SET_SELECTION, args);
        }
    }

    @Override
    public void postGlobalAction(int action) {
        ControlService service = ControlService.getInstance();
        if (service != null) {
            if (!service.performGlobalAction(action)) {
                Log.e(TAG, "could not perform global action: " + action);
            }
        }
    }
}