<?php

namespace Laravel\Prompts;

use Closure;

class MultiSearchPrompt extends Prompt
{
    use Concerns\Scrolling;
    use Concerns\Truncation;
    use Concerns\TypedValue;

    /**
     * The cached matches.
     *
     * @var array<int|string, string>|null
     */
    protected ?array $matches = null;

    /**
     * Whether the matches are initially a list.
     */
    protected bool $isList;

    /**
     * The selected values.
     *
     * @var array<int|string, string>
     */
    public array $values = [];

    /**
     * Create a new MultiSearchPrompt instance.
     *
     * @param  Closure(string): array<int|string, string>  $options
     */
    public function __construct(
        public string $label,
        public Closure $options,
        public string $placeholder = '',
        public int $scroll = 5,
        public bool|string $required = false,
        public mixed $validate = null,
        public string $hint = '',
        public ?Closure $transform = null,
    ) {
        $this->trackTypedValue(submit: false, ignore: fn ($key) => Key::oneOf([Key::SPACE, Key::HOME, Key::END, Key::CTRL_A, Key::CTRL_E], $key) && $this->highlighted !== null);

        $this->initializeScrolling(null);

        $this->on('key', fn ($key) => match ($key) {
            Key::UP, Key::UP_ARROW, Key::SHIFT_TAB => $this->highlightPrevious(count($this->matches), true),
            Key::DOWN, Key::DOWN_ARROW, Key::TAB => $this->highlightNext(count($this->matches), true),
            Key::oneOf(Key::HOME, $key) => $this->highlighted !== null ? $this->highlight(0) : null,
            Key::oneOf(Key::END, $key) => $this->highlighted !== null ? $this->highlight(count($this->matches()) - 1) : null,
            Key::SPACE => $this->highlighted !== null ? $this->toggleHighlighted() : null,
            Key::CTRL_A => $this->highlighted !== null ? $this->toggleAll() : null,
            Key::CTRL_E => null,
            Key::ENTER => $this->submit(),
            Key::LEFT, Key::LEFT_ARROW, Key::RIGHT, Key::RIGHT_ARROW => $this->highlighted = null,
            default => $this->search(),
        });
    }

    /**
     * Perform the search.
     */
    protected function search(): void
    {
        $this->state = 'searching';
        $this->highlighted = null;
        $this->render();
        $this->matches = null;
        $this->firstVisible = 0;
        $this->state = 'active';
    }

    /**
     * Get the entered value with a virtual cursor.
     */
    public function valueWithCursor(int $maxWidth): string
    {
        if ($this->highlighted !== null) {
            return $this->typedValue === ''
                ? $this->dim($this->truncate($this->placeholder, $maxWidth))
                : $this->truncate($this->typedValue, $maxWidth);
        }

        if ($this->typedValue === '') {
            return $this->dim($this->addCursor($this->placeholder, 0, $maxWidth));
        }

        return $this->addCursor($this->typedValue, $this->cursorPosition, $maxWidth);
    }

    /**
     * Get options that match the input.
     *
     * @return array<string>
     */
    public function matches(): array
    {
        if (is_array($this->matches)) {
            return $this->matches;
        }

        $matches = ($this->options)($this->typedValue);

        if (! isset($this->isList) && count($matches) > 0) {
            // This needs to be captured the first time we receive matches so
            // we know what we're dealing with later if matches is empty.
            $this->isList = array_is_list($matches);
        }

        if (! isset($this->isList)) {
            return $this->matches = [];
        }

        if (strlen($this->typedValue) > 0) {
            return $this->matches = $matches;
        }

        return $this->matches = $this->isList
            ? [...array_diff(array_values($this->values), $matches), ...$matches]
            : array_diff($this->values, $matches) + $matches;
    }

    /**
     * The currently visible matches
     *
     * @return array<string>
     */
    public function visible(): array
    {
        return array_slice($this->matches(), $this->firstVisible, $this->scroll, preserve_keys: true);
    }

    /**
     * Toggle all options.
     */
    protected function toggleAll(): void
    {
        $allMatchesSelected = collect($this->matches)->every(fn ($label, $key) => $this->isList()
            ? array_key_exists($label, $this->values)
            : array_key_exists($key, $this->values));

        if ($allMatchesSelected) {
            $this->values = array_filter($this->values, fn ($value) => $this->isList()
                ? ! in_array($value, $this->matches)
                : ! array_key_exists(array_search($value, $this->matches), $this->matches)
            );
        } else {
            $this->values = $this->isList()
                ? array_merge($this->values, array_combine(array_values($this->matches), array_values($this->matches)))
                : array_merge($this->values, array_combine(array_keys($this->matches), array_values($this->matches)));
        }
    }

    /**
     * Toggle the highlighted entry.
     */
    protected function toggleHighlighted(): void
    {
        if ($this->isList()) {
            $label = $this->matches[$this->highlighted];
            $key = $label;
        } else {
            $key = array_keys($this->matches)[$this->highlighted];
            $label = $this->matches[$key];
        }

        if (array_key_exists($key, $this->values)) {
            unset($this->values[$key]);
        } else {
            $this->values[$key] = $label;
        }
    }

    /**
     * Get the current search query.
     */
    public function searchValue(): string
    {
        return $this->typedValue;
    }

    /**
     * Get the selected value.
     *
     * @return array<int|string>
     */
    public function value(): array
    {
        return array_keys($this->values);
    }

    /**
     * Get the selected labels.
     *
     * @return array<string>
     */
    public function labels(): array
    {
        return array_values($this->values);
    }

    /**
     * Whether the matches are initially a list.
     */
    public function isList(): bool
    {
        return $this->isList;
    }
}
