using Paca.Browser;

namespace Paca.Tests.Browser;

// T1-3 페이지 내 검색: FindSession 은 네이티브 Find API(IFindApi) 위의 상태 머신.
public class FindSessionTests
{
    private sealed class FakeFindApi : IFindApi
    {
        public string? LastTerm;
        public int StartCount, NextCount, PrevCount, StopCount;
        public int MatchCount { get; set; }
        public int ActiveIndex { get; set; }

        public event EventHandler<int>? MatchCountChanged;
        public event EventHandler<int>? ActiveMatchIndexChanged;

        public Task StartAsync(string term, bool caseSensitive, bool matchWord, bool highlightAll)
        {
            StartCount++; LastTerm = term; return Task.CompletedTask;
        }
        public void FindNext() => NextCount++;
        public void FindPrevious() => PrevCount++;
        public void Stop() => StopCount++;

        public void RaiseCount(int n) { MatchCount = n; MatchCountChanged?.Invoke(this, n); }
        public void RaiseActive(int n) { ActiveIndex = n; ActiveMatchIndexChanged?.Invoke(this, n); }
    }

    [Fact]
    public async Task Start는_API로_용어를_전달하고_카운트_이벤트를_구독_반영한다()
    {
        var api = new FakeFindApi();
        var session = new FindSession(api);

        await session.StartAsync("hello");
        api.RaiseCount(7);

        Assert.Equal(1, api.StartCount);
        Assert.Equal("hello", api.LastTerm);
        Assert.Equal(7, session.MatchCount);
    }

    [Fact]
    public async Task Next_Previous는_API에_위임한다()
    {
        var api = new FakeFindApi();
        var session = new FindSession(api);
        await session.StartAsync("x");

        session.Next();
        session.Previous();

        Assert.Equal(1, api.NextCount);
        Assert.Equal(1, api.PrevCount);
    }

    [Fact]
    public async Task ActiveMatchIndex_이벤트가_상태에_반영된다()
    {
        var api = new FakeFindApi();
        var session = new FindSession(api);
        await session.StartAsync("x");

        api.RaiseActive(3);
        Assert.Equal(3, session.ActiveMatchIndex);
    }

    [Fact]
    public async Task 빈_용어로_Start하면_Stop만_호출된다()
    {
        var api = new FakeFindApi();
        var session = new FindSession(api);

        await session.StartAsync("   ");

        Assert.Equal(0, api.StartCount);
        Assert.Equal(1, api.StopCount);
        Assert.Equal(0, session.MatchCount);
    }

    [Fact]
    public async Task Close는_Stop을_호출하고_상태를_초기화한다()
    {
        var api = new FakeFindApi();
        var session = new FindSession(api);
        await session.StartAsync("x");
        api.RaiseCount(5);
        api.RaiseActive(2);

        session.Close();

        Assert.Equal(1, api.StopCount);
        Assert.Equal(0, session.MatchCount);
        Assert.Equal(-1, session.ActiveMatchIndex); // -1 = 활성 매치 없음(Start 초기값과 동일 센티넬)
        Assert.Equal(string.Empty, session.Term);
    }
}