using System;
using System.Collections.Generic;
using System.Linq;
using Xunit;
using ytLive.Models;
using ytLive.Services;

namespace ytLive.Tests;

/// <summary>
/// TASK 3·20 — the session report is DERIVED from YouTube, never stored: no ledger, no migration, and the
/// published promise ("no viewer, member or donor information is retained after the session ends") stays
/// literally true.
/// <para>Two rules the creator set (2026-11-05): money is hidden unless asked for, and a creator who never
/// monetized is never shown a zero. Counts stay neutral so a normal session still has something to read.</para>
/// </summary>
public class SessionRewardReportTests
{
    private static readonly DateTime SessionStart = new(2026, 11, 5, 20, 0, 0, DateTimeKind.Utc);

    [Fact]
    public void ParsesBothRewardTypes_WithoutDroppingStickers()
    {
        const string json = """
        {
          "items": [
            {"id":"sc1","snippet":{"publishedAt":"2026-11-05T20:05:00Z","superChatDetails":
              {"amountMicros":5000000,"currency":"USD","amountDisplayString":"$5.00","userComment":"hi"}}},
            {"id":"ss1","snippet":{"publishedAt":"2026-11-05T20:07:00Z","superStickerDetails":
              {"amountMicros":2000000,"currency":"EUR","amountDisplayString":"€2.00"}}}
          ]
        }
        """;

        var events = SuperChatEventService.Parse(json);

        Assert.Equal(2, events.Count);
        Assert.Equal(ChatEventKind.SuperChat, events[0].Kind);
        Assert.Equal(5_000_000, events[0].AmountMicros);
        Assert.Equal("USD", events[0].Currency);
        Assert.Equal(ChatEventKind.SuperSticker, events[1].Kind);
        Assert.Equal("EUR", events[1].Currency);
    }

    [Fact]
    public void TheWindowMakesItASessionReport_NotAChannelReport()
    {
        var events = new[]
        {
            Event(ChatEventKind.SuperChat, 5_000_000, "USD", SessionStart.AddMinutes(-30)),  // before
            Event(ChatEventKind.SuperChat, 3_000_000, "USD", SessionStart.AddMinutes(10)),
            Event(ChatEventKind.SuperSticker, 2_000_000, "USD", SessionStart.AddMinutes(20)),
        };

        var summary = SessionRewardSummary.From(events, SessionStart);

        Assert.Equal(1, summary.SuperChatCount);
        Assert.Equal(1, summary.SuperStickerCount);
        Assert.Equal(5_000_000, summary.MicrosByCurrency["USD"]);
    }

    [Fact]
    public void CurrenciesAreNeverSummedTogether()
    {
        var events = new[]
        {
            Event(ChatEventKind.SuperChat, 5_000_000, "USD", SessionStart.AddMinutes(1)),
            Event(ChatEventKind.SuperChat, 5_000_000, "EUR", SessionStart.AddMinutes(2)),
        };

        var summary = SessionRewardSummary.From(events, SessionStart);

        Assert.Equal(5_000_000, summary.MicrosByCurrency["USD"]);
        Assert.Equal(5_000_000, summary.MicrosByCurrency["EUR"]);
        Assert.Equal(2, summary.MoneyLines().Count);
        Assert.Contains(summary.MoneyLines(), line => line.StartsWith("USD $5.00"));
        Assert.Contains(summary.MoneyLines(), line => line.StartsWith("EUR €5.00"));
    }

    [Fact]
    public void AnEmptySession_HasNoCountsAndNoMoney()
    {
        var summary = SessionRewardSummary.From(Array.Empty<SuperChatEvent>(), SessionStart);

        Assert.False(summary.HasEvents);
        Assert.Empty(summary.MoneyLines());
        Assert.Equal(0, summary.TotalEvents);
    }

    [Fact]
    public void AStickerOnlySession_StillCounts()
    {
        var summary = SessionRewardSummary.From(
            new[] { Event(ChatEventKind.SuperSticker, 1_000_000, "USD", SessionStart.AddMinutes(1)) },
            SessionStart);

        Assert.True(summary.HasEvents);
        Assert.Equal(0, summary.SuperChatCount);
        Assert.Equal(1, summary.SuperStickerCount);
    }

    private static SuperChatEvent Event(ChatEventKind kind, long micros, string currency, DateTime at)
        => new($"id-{Guid.NewGuid():N}", kind, micros, currency, null, at);
}