import { describe, it, expect, vi, afterEach } from 'vitest';
import { cleanup, render } from 'vitest-browser-svelte';
import { page } from 'vitest/browser';
import TranscriptionEditView from './TranscriptionEditView.svelte';

afterEach(cleanup);

const block1 = {
	id: 'b1',
	annotationId: 'a1',
	documentId: 'doc-1',
	text: 'Block eins',
	label: null,
	sortOrder: 0,
	version: 0
};
const block2 = {
	id: 'b2',
	annotationId: 'a2',
	documentId: 'doc-1',
	text: 'Block zwei',
	label: null,
	sortOrder: 1,
	version: 0
};

function renderView(overrides: Record<string, unknown> = {}) {
	return render(TranscriptionEditView, {
		documentId: 'doc-1',
		blocks: [block1, block2],
		canComment: true,
		currentUserId: 'user-1',
		onBlockFocus: vi.fn(),
		onSaveBlock: vi.fn(),
		onDeleteBlock: vi.fn(),
		...overrides
	});
}

describe('TranscriptionEditView — rendering', () => {
	it('renders blocks in sort order', async () => {
		renderView();
		const textareas = page.getByRole('textbox').all();
		expect(textareas.length).toBeGreaterThanOrEqual(2);
	});

	it('shows next-block CTA after block list', async () => {
		renderView();
		await expect.element(page.getByText(/Block 3/)).toBeInTheDocument();
	});

	it('shows empty state when no blocks', async () => {
		renderView({ blocks: [] });
		await expect.element(page.getByText(/Markiere einen Bereich/)).toBeInTheDocument();
	});
});

describe('TranscriptionEditView — annotation sync', () => {
	it('activates block matching activeAnnotationId', async () => {
		renderView({ activeAnnotationId: 'a2' });
		// Block 2 (annotation a2) should have turquoise border
		const block = document.querySelector('[data-block-id="b2"]')!;
		expect(block.className).toContain('border-turquoise');
	});

	it('does not activate any block when activeAnnotationId is null', async () => {
		renderView({ activeAnnotationId: null });
		const block1 = document.querySelector('[data-block-id="b1"]')!;
		const block2 = document.querySelector('[data-block-id="b2"]')!;
		expect(block1.className).not.toContain('border-turquoise');
		expect(block2.className).not.toContain('border-turquoise');
	});
});

describe('TranscriptionEditView — reorder', () => {
	it('renders move-up button disabled on first block', async () => {
		renderView();
		const upButtons = page.getByRole('button', { name: 'Nach oben' }).all();
		// First block's up button should be disabled
		await expect.element(upButtons[0]).toBeDisabled();
	});

	it('renders move-down button disabled on last block', async () => {
		renderView();
		const downButtons = page.getByRole('button', { name: 'Nach unten' }).all();
		// Last block's down button should be disabled
		await expect.element(downButtons[downButtons.length - 1]).toBeDisabled();
	});

	it('has a drag handle on each block', async () => {
		renderView();
		const handles = document.querySelectorAll('[data-drag-handle]');
		expect(handles.length).toBe(2);
	});
});

// ─── Auto-save debounce ───────────────────────────────────────────────────────

describe('TranscriptionEditView — auto-save debounce', () => {
	it('calls onSaveBlock after 1500ms debounce when text changes', async () => {
		vi.useFakeTimers();
		const onSaveBlock = vi.fn().mockResolvedValue(undefined);
		renderView({ onSaveBlock });

		const textarea = page.getByRole('textbox').first();
		await textarea.fill('Neue Zeile');

		// Not called immediately
		expect(onSaveBlock).not.toHaveBeenCalled();

		// Advance past debounce
		vi.advanceTimersByTime(1500);
		await vi.runAllTimersAsync();

		expect(onSaveBlock).toHaveBeenCalledWith('b1', 'Neue Zeile');
		vi.useRealTimers();
	});

	it('resets debounce timer on rapid successive changes', async () => {
		vi.useFakeTimers();
		const onSaveBlock = vi.fn().mockResolvedValue(undefined);
		renderView({ onSaveBlock });

		const textarea = page.getByRole('textbox').first();
		await textarea.fill('First');
		vi.advanceTimersByTime(500);

		await textarea.fill('Second');
		vi.advanceTimersByTime(500);

		// 1000ms elapsed since first change — should not have saved yet
		expect(onSaveBlock).not.toHaveBeenCalled();

		vi.advanceTimersByTime(1000);
		await vi.runAllTimersAsync();

		// Only one save with the final value
		expect(onSaveBlock).toHaveBeenCalledTimes(1);
		expect(onSaveBlock).toHaveBeenCalledWith('b1', 'Second');
		vi.useRealTimers();
	});
});

// ─── Save state transitions ───────────────────────────────────────────────────

describe('TranscriptionEditView — save state indicators', () => {
	it('shows saving indicator while onSaveBlock is in-flight', async () => {
		vi.useFakeTimers();
		let resolveSave!: () => void;
		const onSaveBlock = vi.fn().mockReturnValue(new Promise<void>((r) => (resolveSave = r)));
		renderView({ onSaveBlock });

		await page.getByRole('textbox').first().fill('Hello');
		vi.advanceTimersByTime(1500);
		await vi.runAllTimersAsync();

		await expect.element(page.getByText('Speichere...')).toBeInTheDocument();

		resolveSave();
		vi.useRealTimers();
	});

	it('shows error state when onSaveBlock rejects', async () => {
		vi.useFakeTimers();
		const onSaveBlock = vi.fn().mockRejectedValue(new Error('network'));
		renderView({ onSaveBlock });

		await page.getByRole('textbox').first().fill('Fails');
		vi.advanceTimersByTime(1500);
		await vi.runAllTimersAsync();

		await expect.element(page.getByText('Nicht gespeichert')).toBeInTheDocument();
		await expect.element(page.getByText('Erneut versuchen')).toBeInTheDocument();
		vi.useRealTimers();
	});
});

// ─── Flush on blur ────────────────────────────────────────────────────────────

describe('TranscriptionEditView — flush on blur', () => {
	it('flushes pending save immediately on textarea blur before debounce expires', async () => {
		vi.useFakeTimers();
		const onSaveBlock = vi.fn().mockResolvedValue(undefined);
		renderView({ onSaveBlock });

		const textarea = page.getByRole('textbox').first();
		await textarea.fill('Blur text');

		// Blur before 1500ms debounce fires
		await textarea.blur();

		await vi.runAllTimersAsync();
		expect(onSaveBlock).toHaveBeenCalledWith('b1', 'Blur text');
		vi.useRealTimers();
	});
});

// ─── onDeleteBlock callback ───────────────────────────────────────────────────

describe('TranscriptionEditView — delete block', () => {
	it('calls onDeleteBlock with correct blockId when delete is confirmed', async () => {
		const onDeleteBlock = vi.fn().mockResolvedValue(undefined);
		vi.spyOn(window, 'confirm').mockReturnValue(true);
		renderView({ onDeleteBlock });

		const deleteBtn = page.getByRole('button', { name: 'Löschen' }).first();
		await deleteBtn.click();

		expect(onDeleteBlock).toHaveBeenCalledWith('b1');
		vi.restoreAllMocks();
	});

	it('does not call onDeleteBlock when deletion is cancelled', async () => {
		const onDeleteBlock = vi.fn();
		vi.spyOn(window, 'confirm').mockReturnValue(false);
		renderView({ onDeleteBlock });

		const deleteBtn = page.getByRole('button', { name: 'Löschen' }).first();
		await deleteBtn.click();

		expect(onDeleteBlock).not.toHaveBeenCalled();
		vi.restoreAllMocks();
	});
});