import { describe, expect, it, vi } from 'vitest';
import { selectGameFolder } from '../../src/lib/ui/game-folder.js';

function selectedFile(path: string, size = 10) {
    const read = vi.fn(() => {
        throw new Error('Folder selection must not read file bodies.');
    });
    const file = {
        name: path.split('/').at(-1),
        webkitRelativePath: path,
        size,
        lastModified: 1_700_000_000_000,
        arrayBuffer: read,
        text: read,
        stream: read,
        slice: read
    } as unknown as File;
    return { file, read };
}

describe('game folder selection', () => {
    it('removes the selected root exactly once while preserving nested game paths', () => {
        const first = selectedFile('T6/T6/zone/english/base.ff', 20);
        const second = selectedFile('T6/main/iw_00.iwd', 30);
        const result = selectGameFolder([first.file, second.file]);
        expect(result.name).toBe('T6');
        expect(result.size).toBe(50);
        expect(result.files).toEqual([
            { path: 'T6/zone/english/base.ff', file: first.file },
            { path: 'main/iw_00.iwd', file: second.file }
        ]);
        expect(first.read).not.toHaveBeenCalled();
        expect(second.read).not.toHaveBeenCalled();
    });

    it('prepares multi-gigabyte and empty files using metadata alone', () => {
        const large = selectedFile('Game/zone/base.ff', 7 * 1024 ** 3);
        const empty = selectedFile('Game/empty.txt', 0);
        const result = selectGameFolder([large.file, empty.file]);
        expect(result.size).toBe(7 * 1024 ** 3);
        expect(result.files.map((item) => item.path)).toEqual(['empty.txt', 'zone/base.ff']);
        expect(result.files[1].file).toBe(large.file);
        expect(large.read).not.toHaveBeenCalled();
        expect(empty.read).not.toHaveBeenCalled();
    });

    it('rejects case-insensitive duplicate file names', () => {
        expect(() =>
            selectGameFolder([
                selectedFile('Game/Zone/base.ff').file,
                selectedFile('Game/zone/BASE.ff').file
            ])
        ).toThrow('duplicate game paths');
    });

    it('rejects a path used as both a file and a directory regardless of case', () => {
        expect(() =>
            selectGameFolder([
                selectedFile('Game/zone/english/base.ff').file,
                selectedFile('Game/ZONE').file
            ])
        ).toThrow('same game path for a file and a directory');
    });

    it.each(['../base.ff', './base.ff', '/Game/base.ff', 'base.ff'])(
        'rejects an absent or parent root in %s',
        (path) => {
            expect(() => selectGameFolder([selectedFile(path).file])).toThrow('one game folder');
        }
    );

    it.each(['Game/../base.ff', 'Game/zone/./base.ff', 'Game/zone//base.ff', 'Game/zone\\base.ff'])(
        'rejects traversal and non-normalized content paths in %s',
        (path) => {
            expect(() => selectGameFolder([selectedFile(path).file])).toThrow(
                'unsupported game path'
            );
        }
    );

    it('rejects files from multiple selected roots', () => {
        expect(() =>
            selectGameFolder([
                selectedFile('T5/main/base.ff').file,
                selectedFile('T6/main/base.ff').file
            ])
        ).toThrow('one game folder');
    });

    it('rejects empty selections', () => {
        expect(() => selectGameFolder([])).toThrow('contains no files');
    });
});