<script lang="ts">
	import MdiIcon from './MdiIcon.svelte';
	import { t } from '$lib/i18n';
	import { portal } from '$lib/portal';

	export interface MultiEntityItem {
		value: string;
		label: string;
		icon?: string;
		desc?: string;
	}

	let {
		items = [],
		values = $bindable<string[]>(),
		placeholder = 'Select...',
		size = 'default',
		onchange,
	}: {
		items: MultiEntityItem[];
		values: string[];
		placeholder?: string;
		size?: 'sm' | 'default';
		onchange?: (values: string[]) => void;
	} = $props();

	let open = $state(false);
	let query = $state('');
	let highlightIdx = $state(0);
	let inputEl = $state<HTMLInputElement | undefined>();
	let listEl = $state<HTMLDivElement | undefined>();

	const selectedItems = $derived(items.filter(i => (values || []).includes(i.value)));

	const filtered = $derived.by(() => {
		const q = query.toLowerCase().trim();
		return q
			? items.filter(i => i.label.toLowerCase().includes(q) || (i.desc || '').toLowerCase().includes(q))
			: items;
	});

	function openPalette() {
		open = true;
		query = '';
		highlightIdx = 0;
		requestAnimationFrame(() => inputEl?.focus());
	}

	function closePalette() {
		open = false;
		query = '';
	}

	function toggleItem(item: MultiEntityItem) {
		const current = values || [];
		if (current.includes(item.value)) {
			values = current.filter(v => v !== item.value);
		} else {
			values = [...current, item.value];
		}
		onchange?.(values);
	}

	function removeItem(value: string) {
		values = (values || []).filter(v => v !== value);
		onchange?.(values);
	}

	function handleKeydown(e: KeyboardEvent) {
		if (e.key === 'Escape') { closePalette(); return; }
		if (e.key === 'ArrowDown') {
			e.preventDefault();
			highlightIdx = Math.min(highlightIdx + 1, filtered.length - 1);
			scrollToHighlight();
		} else if (e.key === 'ArrowUp') {
			e.preventDefault();
			highlightIdx = Math.max(highlightIdx - 1, 0);
			scrollToHighlight();
		} else if (e.key === 'Enter') {
			e.preventDefault();
			if (filtered[highlightIdx]) toggleItem(filtered[highlightIdx]);
		}
	}

	function scrollToHighlight() {
		requestAnimationFrame(() => {
			listEl?.querySelector('.mes-highlight')?.scrollIntoView({ block: 'nearest' });
		});
	}

	$effect(() => { query; highlightIdx = 0; });
</script>

<!-- Trigger: chips + button -->
<div class="mes-trigger-wrap" class:mes-sm={size === 'sm'}>
	{#if selectedItems.length > 0}
		<div class="mes-chips">
			{#each selectedItems as item}
				<span class="mes-chip">
					{#if item.icon}<span class="mes-chip-icon"><MdiIcon name={item.icon} size={12} /></span>{/if}
					<span class="mes-chip-label">{item.label}</span>
					<button type="button" class="mes-chip-remove" onclick={() => removeItem(item.value)}>&times;</button>
				</span>
			{/each}
		</div>
	{/if}
	<button type="button" class="mes-trigger" onclick={openPalette}>
		<MdiIcon name="mdiPlus" size={14} />
		<span>{(values || []).length === 0 ? placeholder : t('common.nSelected').replace('{0}', String((values || []).length))}</span>
		<span class="mes-trigger-arrow"><MdiIcon name="mdiChevronDown" size={14} /></span>
	</button>
</div>

<!-- Palette overlay — portalled to <body> to escape backdrop-filter ancestors -->
{#if open}
	<div use:portal class="mes-portal-root">
		<div class="mes-overlay" onclick={closePalette} role="presentation"></div>

		<div class="mes-container">
			<div class="mes-search-row">
				<MdiIcon name="mdiMagnify" size={18} />
				<input
					bind:this={inputEl}
					bind:value={query}
					placeholder={t('common.search')}
					class="mes-input"
					type="text"
					autocomplete="off"
					spellcheck="false"
					onkeydown={handleKeydown}
				/>
				<span class="mes-count">{(values || []).length}/{items.length}</span>
				<kbd class="mes-kbd">ESC</kbd>
			</div>

			<div class="mes-list" bind:this={listEl} role="listbox">
				{#if filtered.length === 0}
					<div class="mes-empty">{t('common.noMatches')}</div>
				{:else}
					{#each filtered as item, i}
						{@const checked = (values || []).includes(item.value)}
						<button
							class="mes-item"
							class:mes-highlight={i === highlightIdx}
							class:mes-checked={checked}
							role="option"
							aria-selected={checked}
							onclick={() => toggleItem(item)}
							onmouseenter={() => highlightIdx = i}
							type="button"
						>
							<span class="mes-item-check">
								<MdiIcon name={checked ? 'mdiCheckboxMarked' : 'mdiCheckboxBlankOutline'} size={16} />
							</span>
							{#if item.icon}
								<span class="mes-item-icon"><MdiIcon name={item.icon} size={18} /></span>
							{/if}
							<span class="mes-item-label">{item.label}</span>
							{#if item.desc}
								<span class="mes-item-desc">{item.desc}</span>
							{/if}
						</button>
					{/each}
				{/if}
			</div>
		</div>
	</div>
{/if}

<style>
	.mes-trigger-wrap {
		display: flex;
		flex-direction: column;
		gap: 0.375rem;
	}
	.mes-chips {
		display: flex;
		flex-wrap: wrap;
		gap: 0.25rem;
	}
	.mes-chip {
		display: inline-flex;
		align-items: center;
		gap: 0.25rem;
		font-size: 0.75rem;
		padding: 0.125rem 0.5rem;
		border-radius: 9999px;
		background: color-mix(in srgb, var(--color-primary) 10%, transparent);
		color: var(--color-primary);
		border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
	}
	.mes-chip-icon {
		display: flex;
		align-items: center;
	}
	.mes-chip-label {
		max-width: 12rem;
		overflow: hidden;
		text-overflow: ellipsis;
		white-space: nowrap;
	}
	.mes-chip-remove {
		cursor: pointer;
		font-size: 0.875rem;
		line-height: 1;
		opacity: 0.6;
		transition: opacity 0.1s;
	}
	.mes-chip-remove:hover {
		opacity: 1;
	}

	.mes-trigger {
		display: flex;
		align-items: center;
		gap: 0.375rem;
		width: 100%;
		padding: 0.375rem 0.625rem;
		border: 1px solid var(--color-border);
		border-radius: 0.375rem;
		font-size: 0.8rem;
		background: var(--color-background);
		color: var(--color-muted-foreground);
		cursor: pointer;
		transition: border-color 0.15s;
	}
	.mes-sm .mes-trigger {
		padding: 0.25rem 0.5rem;
		font-size: 0.75rem;
	}
	.mes-trigger:hover {
		border-color: var(--color-primary);
	}
	.mes-trigger-arrow {
		margin-left: auto;
		flex-shrink: 0;
	}

	/* Portal root */
	.mes-portal-root {
		position: fixed;
		inset: 0;
		z-index: 9998;
		pointer-events: none;
	}
	.mes-overlay {
		position: absolute;
		inset: 0;
		pointer-events: auto;
		background: rgba(0, 0, 0, 0.55);
		backdrop-filter: blur(8px) saturate(120%);
		-webkit-backdrop-filter: blur(8px) saturate(120%);
	}

	/* Palette container — solid background for legibility */
	.mes-container {
		pointer-events: auto;
		position: absolute;
		top: min(20vh, 120px);
		left: 50%;
		transform: translateX(-50%);
		z-index: 1;
		width: min(480px, 92vw);
		max-height: 60vh;
		background: var(--mes-solid-bg);
		border: 1px solid var(--color-rule-strong);
		border-radius: 16px;
		box-shadow: var(--shadow-card), 0 24px 48px -16px rgba(0, 0, 0, 0.55);
		display: flex;
		flex-direction: column;
		overflow: hidden;
		--mes-solid-bg: #131520;
	}
	:global([data-theme="light"]) .mes-container { --mes-solid-bg: #fafafe; }

	.mes-search-row {
		display: flex;
		align-items: center;
		gap: 0.5rem;
		padding: 0.625rem 0.875rem;
		border-bottom: 1px solid var(--color-border);
		color: var(--color-muted-foreground);
	}
	.mes-input {
		flex: 1;
		border: none;
		outline: none;
		background: transparent;
		font-size: 0.9rem;
		color: var(--color-foreground);
		padding: 0;
	}
	.mes-count {
		font-size: 0.7rem;
		color: var(--color-muted-foreground);
		white-space: nowrap;
	}
	.mes-kbd {
		font-size: 0.55rem;
		font-family: var(--font-mono);
		padding: 0.1rem 0.3rem;
		border-radius: 0.2rem;
		background: var(--color-muted);
		color: var(--color-muted-foreground);
		border: 1px solid var(--color-border);
	}

	.mes-list {
		overflow-y: auto;
		overscroll-behavior: contain;
		scrollbar-width: thin;
		padding: 0.25rem 0;
	}
	.mes-empty {
		padding: 1rem;
		text-align: center;
		color: var(--color-muted-foreground);
		font-size: 0.85rem;
	}

	.mes-item {
		display: flex;
		align-items: center;
		gap: 0.5rem;
		width: 100%;
		padding: 0.4rem 0.875rem;
		border: none;
		background: transparent;
		color: var(--color-foreground);
		font-size: 0.875rem;
		cursor: pointer;
		text-align: left;
		transition: background 0.1s;
	}
	.mes-item:hover, .mes-item.mes-highlight {
		background: rgba(255, 255, 255, 0.06);
	}
	:global([data-theme="light"]) .mes-item:hover,
	:global([data-theme="light"]) .mes-item.mes-highlight {
		background: rgba(20, 15, 60, 0.05);
	}
	.mes-item-check {
		flex-shrink: 0;
		display: flex;
		align-items: center;
		color: var(--color-muted-foreground);
	}
	.mes-item.mes-checked .mes-item-check {
		color: var(--color-primary);
	}
	.mes-item-icon {
		flex-shrink: 0;
		display: flex;
		align-items: center;
		color: var(--color-muted-foreground);
	}
	.mes-item-label {
		flex: 1;
		overflow: hidden;
		text-overflow: ellipsis;
		white-space: nowrap;
	}
	.mes-item-desc {
		font-size: 0.75rem;
		color: var(--color-muted-foreground);
		white-space: nowrap;
		overflow: hidden;
		text-overflow: ellipsis;
		max-width: 40%;
	}
</style>
