<?php

namespace App\Gui;

use JumPHP\Gui\Pointer;
use JumPHP\Gui\Theme;
use JumPHP\Renderer\Renderer;

/**
 * A table with a header (the Storage, Networking, Snapshots, Search, Events lists): columns [['title' => 'Name', 'width' => 3,
 * 'align' => 'right'], ...] (widths share the room), rows [['id' => 'OpaqueRef:...', 'cells' => [...], 'icon' => 'vm-running',
 * 'muted' => bool]]. A cell is a text, or ['bar' => 0.42, 'text' => '42%', 'color' => '#...'] (a usage bar), or ['icon' => .., 'text' => ..].
 * A click on a header sorts by it. Events: change (?string $id), activate (string $id), contextmenu (x, y).
 *
 * @property string $empty
 */
final class DataGrid extends Canvas
{
    public const DEFAULTS = ['height' => 'fill', 'width' => 'fill', 'background' => '#ffffff', 'border' => true, 'empty' => ''];

    /** @var list<array<string, mixed>> */
    public array $columns = [];
    /** @var list<array<string, mixed>> */
    public array $rows = [];
    public ?string $selected = null;
    public int $sortColumn = -1;
    public bool $sortDescending = false;

    public static function events(): array
    {
        return ['change', 'activate', 'contextmenu', 'click'];
    }

    public function focusable(): bool
    {
        return true;
    }

    /** @param list<array<string, mixed>> $columns @param list<array<string, mixed>> $rows */
    public function set(array $columns, array $rows): void
    {
        if (array_column($columns, 'title') !== array_column($this->columns, 'title')) {
            $this->sortColumn = -1;
            $this->scrollY = 0;
        }
        $this->columns = $columns;
        $this->rows = $rows;
        $this->sort();
        if ($this->selected !== null && !in_array($this->selected, array_column($this->rows, 'id'), true)) {
            $this->selected = null;
        }
        $this->form?->invalidate();
    }

    public function selectedRow(): ?array
    {
        foreach ($this->rows as $row) {
            if (($row['id'] ?? null) === $this->selected) {
                return $row;
            }
        }
        return null;
    }

    public function select(?string $id): void
    {
        if ($id !== $this->selected) {
            $this->selected = $id;
            $this->emit('change', $id);
        }
    }

    private function sort(): void
    {
        if ($this->sortColumn < 0) {
            return;
        }
        $c = $this->sortColumn;
        $key = function (array $row) use ($c): mixed {
            $cell = $row['sort'][$c] ?? $row['cells'][$c] ?? '';
            return is_array($cell) ? ($cell['sort'] ?? $cell['bar'] ?? $cell['text'] ?? '') : $cell;
        };
        // numbers as numbers (0.42 < 0.5, sizes over 2 GiB), the rest as natural text
        $compare = fn (mixed $a, mixed $b): int => is_numeric($a) && is_numeric($b) ? ((float)$a <=> (float)$b) : strnatcasecmp((string)$a, (string)$b);
        usort($this->rows, fn ($a, $b) => ($this->sortDescending ? -1 : 1) * $compare($key($a), $key($b)));
    }

    private function headerHeight(Theme $t): float
    {
        return $t->px(32);
    }

    public function rowHeight(Theme $t): float
    {
        return $t->px(30);
    }

    protected function scrollTop(Theme $t): float
    {
        return $this->headerHeight($t);
    }

    protected function contentHeight(Theme $t): float
    {
        return count($this->rows) * $this->rowHeight($t) + $t->px(2);
    }

    /** @return list<array{0: float, 1: float}> x and width of each column */
    private function columnBoxes(Theme $t): array
    {
        $total = 0;
        foreach ($this->columns as $col) {
            $total += (float)($col['width'] ?? 1);
        }
        $room = $this->w - $t->px(12);
        $x = $this->x;
        $out = [];
        foreach ($this->columns as $col) {
            $w = $room * (float)($col['width'] ?? 1) / max(0.01, $total);
            $out[] = [$x, $w];
            $x += $w;
        }
        return $out;
    }

    protected function paint(Renderer $r, Theme $t): void
    {
        $font = $t->font();
        $boxes = $this->columnBoxes($t);
        $hh = $this->headerHeight($t);
        $rh = $this->rowHeight($t);
        $pad = $t->px(10);
        $top = $this->y + $hh;
        $first = max(0, (int)floor($this->scrollY / $rh));
        $last = min(count($this->rows) - 1, (int)ceil(($this->scrollY + $this->h) / $rh));
        for ($i = $first; $i <= $last; $i++) {
            $row = $this->rows[$i];
            $y = $top + $i * $rh - $this->scrollY;
            $selected = ($row['id'] ?? null) === $this->selected && $this->selected !== null;
            if ($selected) {
                $r->fillRect($this->x + 1, $y, $this->w - 2, $rh, $this->focused ? '#dce8fb' : '#ebf1fb');
            }
            $r->fillRect($this->x + $t->px(6), $y + $rh - 1, $this->w - $t->px(12), 1, '#eef0f3');
            foreach ($boxes as $c => [$x, $w]) {
                $cell = $row['cells'][$c] ?? '';
                $cx = $x + $pad;
                $cw = $w - 2 * $pad;
                if ($c === 0 && !empty($row['icon'])) {
                    Icons::draw($r, (string)$row['icon'], $cx, $y + ($rh - $t->px(16)) / 2, $t->px(16));
                    $cx += $t->px(22);
                    $cw -= $t->px(22);
                }
                $color = !empty($row['muted']) ? '#8a8a8a' : (string)($row['color'] ?? '#1a1a1a');
                if (is_array($cell) && isset($cell['icon'])) {
                    Icons::draw($r, (string)$cell['icon'], $cx, $y + ($rh - $t->px(16)) / 2, $t->px(16));
                    $cx += $t->px(22);
                    $cw -= $t->px(22);
                }
                if (is_array($cell) && isset($cell['bar'])) {
                    $ratio = max(0.0, min(1.0, (float)$cell['bar']));
                    $bh = $rh - $t->px(12);
                    $by = $y + $t->px(6);
                    $t->box($r, $cx, $by, $cw, $bh, '#e9edf2', $t->px(4));
                    if ($ratio > 0) {
                        $t->box($r, $cx, $by, max($t->px(8), $cw * $ratio), $bh, (string)($cell['color'] ?? ($ratio > 0.9 ? '#e5735f' : '#7cc47f')), $t->px(4));
                    }
                    $text = (string)($cell['text'] ?? '');
                    $font->draw($r, self::fit($font, $text, $cw), $cx + $cw / 2, $y + ($rh - $font->height()) / 2, 1, '#1a1a1a', 'center');
                    continue;
                }
                $text = self::oneLine(is_array($cell) ? (string)($cell['text'] ?? '') : (string)$cell);
                $text = self::fit($font, $text, $cw);
                $align = (string)($this->columns[$c]['align'] ?? 'left');
                $font->draw($r, $text, $align === 'right' ? $cx + $cw : $cx, $y + ($rh - $font->height()) / 2, 1, is_array($cell) && isset($cell['color']) ? (string)$cell['color'] : $color, $align);
            }
        }
        if ($this->rows === [] && $this->props['empty'] !== '') {
            $t->font(null)->draw($r, \JumPHP\Util\Lang::t((string)$this->props['empty']), $this->x + $this->w / 2, $top + $t->px(18), 1, '#8a8a8a', 'center');
        }
        // the header stays on top
        $r->fillRect($this->x, $this->y, $this->w, $hh, '#f7f8fa');
        $r->fillRect($this->x, $this->y + $hh - 1, $this->w, 1, '#e1e5eb');
        $font = $t->font($t->fontSize * 0.95, true);
        foreach ($boxes as $c => [$x, $w]) {
            $title = \JumPHP\Util\Lang::t((string)$this->columns[$c]['title']);
            $align = (string)($this->columns[$c]['align'] ?? 'left');
            $font->draw($r, self::fit($font, $title, $w - 2 * $pad - $t->px(10)), $align === 'right' ? $x + $w - $pad : $x + $pad, $this->y + ($hh - $font->height()) / 2, 1, '#57606a', $align);
            if ($c > 0) {
                $r->fillRect($x, $this->y + $t->px(9), 1, $hh - $t->px(18), '#dde2e8');
            }
            if ($c === $this->sortColumn) {
                $ax = $align === 'right' ? $x + $t->px(8) : $x + $w - $t->px(12);
                for ($k = 0; $k < 4; $k++) {
                    $ay = $this->sortDescending ? $this->y + $hh / 2 - $t->px(2) + $k : $this->y + $hh / 2 + $t->px(2) - $k;
                    $r->fillRect($ax + $k * $t->scale, $ay, max(1, $t->px(7) - 2 * $k * $t->scale), 1, '#606060');
                }
            }
        }
    }

    /** A cell is one line: line breaks and tabs (XAPI's message bodies have them) become spaces, else the text runs over the rows below. */
    public static function oneLine(string $text): string
    {
        return trim((string)preg_replace('/\s+/u', ' ', $text));
    }

    private function rowAt(float $py): ?int
    {
        $t = $this->form?->theme;
        if ($t === null || $py < $this->y + $this->headerHeight($t)) {
            return null;
        }
        $index = (int)floor(($py - $this->y - $this->headerHeight($t) + $this->scrollY) / $this->rowHeight($t));
        return isset($this->rows[$index]) ? $index : null;
    }

    protected function contextAt(float $x, float $y): void
    {
        $index = $this->rowAt($y);
        $this->select($index === null ? null : (string)($this->rows[$index]['id'] ?? ''));
    }

    public function pointerUp(Pointer $p, bool $inside): void
    {
        if ($this->popupUp($p) || $this->barUp() || !$inside || $this->form === null) {
            return;
        }
        $t = $this->form->theme;
        if ($p->y < $this->y + $this->headerHeight($t)) {
            foreach ($this->columnBoxes($t) as $c => [$x, $w]) {
                if ($p->x >= $x && $p->x < $x + $w) {
                    $this->sortDescending = $this->sortColumn === $c && !$this->sortDescending;
                    $this->sortColumn = $c;
                    $this->sort();
                }
            }
            return;
        }
        $index = $this->rowAt($p->y);
        $this->select($index === null ? null : (string)($this->rows[$index]['id'] ?? ''));
        if ($index !== null && $p->double) {
            $this->emit('activate', (string)($this->rows[$index]['id'] ?? ''));
        }
        $this->emit('click');
    }

    public function keys(Pointer $p): bool
    {
        if ($this->popup !== null) {
            if ($p->pressed(Pointer::ESCAPE)) {
                $this->close();
            }
            return true;           // the keys do not move the selection under an open menu
        }
        if ($this->popupKeys($p)) {
            return true;
        }
        $ids = array_map(fn ($row) => (string)($row['id'] ?? ''), $this->rows);
        if ($ids === []) {
            return false;
        }
        $at = $this->selected === null ? -1 : (int)array_search($this->selected, $ids, true);
        foreach ($p->keys as $key) {
            if ($key === Pointer::UP) {
                $at = max(0, $at - 1);
            } elseif ($key === Pointer::DOWN) {
                $at = min(count($ids) - 1, $at + 1);
            } elseif (($key === Pointer::RETURN || $key === Pointer::KP_ENTER) && $this->selected !== null) {
                $this->emit('activate', $this->selected);
                return true;
            } else {
                continue;
            }
            $this->select($ids[$at]);
            $t = $this->form?->theme;
            if ($t !== null) {
                $rh = $this->rowHeight($t);
                $this->scrollY = max(min($this->scrollY, $at * $rh), ($at + 1) * $rh - $this->viewHeight($t) + $t->px(2));
            }
            return true;
        }
        return false;
    }
}