<?php

declare(strict_types=1);

require_once __DIR__ . '/../vendor/autoload.php';

use PHPNative\Framework\Application;
use PHPNative\Ui\Widget\Button;
use PHPNative\Ui\Widget\Container;
use PHPNative\Ui\Widget\Label;
use PHPNative\Ui\Widget\TextInput;
use PHPNative\Ui\Window;

final class KanbanTaskCard extends Container
{
    public function __construct(
        private readonly string $boardId,
        private readonly array $task,
        private KanbanBoardView $boardView,
    ) {
        parent::__construct('bg-white border border-gray-200 rounded shadow px-3 py-2 cursor-pointer');

        $title = new Label($task['title'], 'text-sm text-black');
        $this->addComponent($title);
        if (!empty($task['note'] ?? '')) {
            $this->addComponent(new Label($task['note'], 'text-xs text-gray-500'));
        }
    }

    public function handleMouseClick(float $mouseX, float $mouseY, int $button): bool
    {
        if ($button !== 1) {
            return false;
        }

        $this->boardView->beginDrag($this->boardId, $this->task);
        return true;
    }
}

final class KanbanBoardView extends Container
{
    private array $boards;
    private array $boardViews = [];
    private null|array $dragState = null;
    private null|string $hoverBoardId = null;

    public function __construct(
        private readonly string $storagePath,
        array $initialBoards,
        private readonly Label $statusLabel,
    ) {
        parent::__construct('flex flex-row gap-4 flex-1');
        $this->boards = $initialBoards;

        $this->renderBoards();
    }

    public function addBoard(string $title): void
    {
        $title = trim($title);
        if ($title === '') {
            $this->statusLabel->setText('Board-Namen eingeben, um es hinzuzufügen.');
            return;
        }

        $this->boards[] = [
            'id' => uniqid('board_', true),
            'title' => $title,
            'tasks' => [],
        ];

        $this->saveBoards();
        $this->renderBoards();
        $this->statusLabel->setText('Board hinzugefügt: ' . $title);
    }

    public function addTask(string $boardId, string $title): void
    {
        $title = trim($title);
        if ($title === '') {
            $this->statusLabel->setText('Bitte einen Aufgabentitel eingeben.');
            return;
        }

        foreach ($this->boards as &$board) {
            if ($board['id'] === $boardId) {
                $board['tasks'][] = [
                    'id' => uniqid('task_', true),
                    'title' => $title,
                    'note' => '',
                ];
                $this->saveBoards();
                $this->renderBoards();
                $this->statusLabel->setText(sprintf('Aufgabe "%s" zu "%s" hinzugefügt.', $title, $board['title']));
                return;
            }
        }

        $this->statusLabel->setText('Board nicht gefunden.');
    }

    public function beginDrag(string $boardId, array $task): void
    {
        $this->dragState = [
            'fromBoardId' => $boardId,
            'taskId' => $task['id'],
            'taskData' => $task,
        ];
        $this->statusLabel->setText('Verschiebe: ' . $task['title']);
    }

    public function handleMouseMove(float $mouseX, float $mouseY): void
    {
        parent::handleMouseMove($mouseX, $mouseY);

        if ($this->dragState === null) {
            return;
        }

        $target = $this->findBoardAt($mouseX, $mouseY);
        if ($target !== $this->hoverBoardId) {
            if ($this->hoverBoardId !== null) {
                $this->setBoardHighlight($this->hoverBoardId, false);
            }
            if ($target !== null) {
                $this->setBoardHighlight($target, true);
            }
            $this->hoverBoardId = $target;
        }
    }

    public function handleMouseRelease(float $mouseX, float $mouseY, int $button): void
    {
        parent::handleMouseRelease($mouseX, $mouseY, $button);

        if ($this->dragState === null || $button !== 1) {
            return;
        }

        $dropTarget = $this->findBoardAt($mouseX, $mouseY);
        $this->completeDrag($dropTarget);
    }

    private function renderBoards(): void
    {
        $this->clearChildren();
        $this->boardViews = [];

        foreach ($this->boards as $board) {
            $style = 'flex flex-col w-[260] flex-none bg-white border border-black rounded-lg p-3 gap-2';

            $column = new Container($style);
            $column->addComponent(new Label('Board: ' . $board['title'], 'text-lg font-bold text-black'));

            $taskTitles = array_map(static fn($t) => $t['title'], $board['tasks']);
            $tasksText = empty($taskTitles) ? '(keine Aufgaben)' : implode(', ', $taskTitles);
            $column->addComponent(new Label('Tasks: ' . $tasksText, 'text-xs text-black'));

            if (!empty($board['tasks'])) {
                $taskList = new Container('flex flex-col gap-2 mt-2');
                foreach ($board['tasks'] as $task) {
                    $card = new Container('bg-white border-2 border-gray-400 rounded px-2 py-1 shadow-md');
                    $card->addComponent(new Label($task['title'], 'text-sm text-black'));
                    $taskList->addComponent($card);
                }
                $column->addComponent($taskList);
            }

            $this->addComponent($column);
            $this->boardViews[$board['id']] = [
                'column' => $column,
                'defaultStyle' => $style,
                'highlightStyle' => $style,
            ];
        }
    }

    private function findBoardAt(float $mouseX, float $mouseY): null|string
    {
        foreach ($this->boardViews as $boardId => $info) {
            $viewport = $info['column']->getViewport();
            if (
                $mouseX >= $viewport->x &&
                    $mouseX <= ($viewport->x + $viewport->width) &&
                    $mouseY >= $viewport->y &&
                    $mouseY <= ($viewport->y + $viewport->height)
            ) {
                return $boardId;
            }
        }

        return null;
    }

    private function setBoardHighlight(string $boardId, bool $active): void
    {
        if (!isset($this->boardViews[$boardId])) {
            return;
        }

        $column = $this->boardViews[$boardId]['column'];
        $style = $active ? $this->boardViews[$boardId]['highlightStyle'] : $this->boardViews[$boardId]['defaultStyle'];
        $column->setStyle($style);
    }

    private function completeDrag(null|string $targetBoardId): void
    {
        $state = $this->dragState;
        $this->dragState = null;

        if ($this->hoverBoardId !== null) {
            $this->setBoardHighlight($this->hoverBoardId, false);
            $this->hoverBoardId = null;
        }

        if (!$state) {
            return;
        }

        if ($targetBoardId === null) {
            $this->statusLabel->setText('Ziehen abgebrochen.');
            return;
        }

        if ($targetBoardId === $state['fromBoardId']) {
            $this->statusLabel->setText('Aufgabe blieb im gleichen Board.');
            return;
        }

        $movedTask = null;
        foreach ($this->boards as &$board) {
            if ($board['id'] === $state['fromBoardId']) {
                foreach ($board['tasks'] as $index => $task) {
                    if ($task['id'] === $state['taskId']) {
                        $movedTask = $task;
                        array_splice($board['tasks'], $index, 1);
                        break 2;
                    }
                }
            }
        }

        if ($movedTask === null) {
            $this->statusLabel->setText('Aufgabe konnte nicht verschoben werden.');
            return;
        }

        foreach ($this->boards as &$board) {
            if ($board['id'] === $targetBoardId) {
                $board['tasks'][] = $movedTask;
                break;
            }
        }

        $this->saveBoards();
        $this->renderBoards();

        $this->statusLabel->setText(sprintf(
            '"%s" nach "%s" verschoben.',
            $movedTask['title'],
            $this->getBoardTitle($targetBoardId),
        ));
    }

    private function getBoardTitle(string $boardId): string
    {
        foreach ($this->boards as $board) {
            if ($board['id'] === $boardId) {
                return $board['title'];
            }
        }

        return $boardId;
    }

    private function saveBoards(): void
    {
        file_put_contents(
            $this->storagePath,
            json_encode($this->boards, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE),
            LOCK_EX,
        );
    }
}

$storagePath = __DIR__ . '/kanban_data.json';

$boards = [];
if (is_file($storagePath)) {
    $raw = file_get_contents($storagePath);
    $decoded = json_decode($raw ?: '[]', true);
    if (is_array($decoded)) {
        $boards = $decoded;
    }
}

if (empty($boards)) {
    $boards = [
        [
            'id' => uniqid('board_', true),
            'title' => 'Backlog',
            'tasks' => [
                ['id' => uniqid('task_', true), 'title' => 'Idee sammeln', 'note' => ''],
                ['id' => uniqid('task_', true), 'title' => 'Mockups skizzieren', 'note' => ''],
            ],
        ],
        [
            'id' => uniqid('board_', true),
            'title' => 'In Arbeit',
            'tasks' => [
                ['id' => uniqid('task_', true), 'title' => 'API anbinden', 'note' => ''],
            ],
        ],
        [
            'id' => uniqid('board_', true),
            'title' => 'Erledigt',
            'tasks' => [
                ['id' => uniqid('task_', true), 'title' => 'UI Grundlayout', 'note' => ''],
            ],
        ],
    ];
    file_put_contents($storagePath, json_encode($boards, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE), LOCK_EX);
}

$app = new Application();
$window = new Window('Kanban Beispiel', 1200, 800);

$root = new Container('flex flex-col h-full w-full bg-gray-100 gap-4 p-4');

$title = new Label('Kanban Board', 'text-3xl font-bold text-black');
$subTitle = new Label(
    'Boards hinzufügen, Aufgaben erstellen und per Drag & Drop verschieben.',
    'text-base text-gray-700',
);
$root->addComponent($title);
$root->addComponent($subTitle);

$statusLabel = new Label('Bereit.', 'text-sm text-gray-600');
$kanbanView = new KanbanBoardView($storagePath, $boards, $statusLabel);

$boardInput = new TextInput('Neues Board', 'flex-1 border border-gray-300 rounded px-3 py-2 bg-white text-black');
$boardAddButton = new Button('Board hinzufügen', 'px-4 py-2 bg-blue-600 text-white rounded hover:bg-blue-700');
$boardAddButton->setOnClick(function () use ($kanbanView, $boardInput, $statusLabel): void {
    $kanbanView->addBoard($boardInput->getValue());
    $boardInput->setValue('');
});
$boardRow = new Container('flex flex-row gap-3 items-center');
$boardRow->addComponent($boardInput);
$boardRow->addComponent($boardAddButton);
$root->addComponent($boardRow);

$root->addComponent($kanbanView);
$root->addComponent($statusLabel);

$window->setRoot($root);
$app->addWindow($window);
$app->run();