using System;
using System.Collections.Generic;
using System.Linq;
using ExperionCrawler.Core.Application.Feedforward;
using ExperionCrawler.Infrastructure.Control;
using Xunit;

namespace ExperionCrawler.Tests;

public class FeedforwardRecoveryTests
{
    private static ColumnConfig Cfg(bool autoArm) => new()
    {
        Id = 1, Name = "C-REC", Enabled = true, FeedTag = "f", ProductKey = "P",
        ScanSec = 2, BiasMaWindowSec = 4,
        RecoveryEnabled = true, RecoveryAutoArm = autoArm,
        ImbalanceTriggerFrac = 0.10, ImbalanceTriggerSec = 4,
        RecoverySettleSec = 4, ReturnRampSec = 4, FeedRecoverySp = 0,
        Streams = new[]
        {
            new StreamConfig { Key="P", FlowTag="p", Role=StreamRole.Commanded,   Grade=Confidence.A, TargetCoeff=0.95, SpMax=950 },
            new StreamConfig { Key="R", FlowTag="r", Role=StreamRole.Commanded,   Grade=Confidence.A, TargetCoeff=0.80, SpMax=1100, RefluxFromProduct=true },
            new StreamConfig { Key="D", FlowTag="d", Role=StreamRole.LevelDriven, Grade=Confidence.B, TargetCoeff=0.02, SpMax=60 },
            new StreamConfig { Key="B", FlowTag="b", Role=StreamRole.LevelDriven, Grade=Confidence.B, TargetCoeff=0.03, SpMax=80 },
        }
    };

    private static PvSnapshot Imbalanced() => new(
        new TagSample("f", 100, true, DateTime.UtcNow), null, Array.Empty<TagSample>(),
        new Dictionary<string, TagSample> {
            ["P"]=new("p",30,true,DateTime.UtcNow), ["R"]=new("r",50,true,DateTime.UtcNow),
            ["D"]=new("d",2,true,DateTime.UtcNow),  ["B"]=new("b",3,true,DateTime.UtcNow) });

    private static PvSnapshot Balanced() => new(
        new TagSample("f", 100, true, DateTime.UtcNow), null, Array.Empty<TagSample>(),
        new Dictionary<string, TagSample> {
            ["P"]=new("p",95,true,DateTime.UtcNow), ["R"]=new("r",760,true,DateTime.UtcNow),
            ["D"]=new("d",2,true,DateTime.UtcNow),  ["B"]=new("b",3,true,DateTime.UtcNow) });

    [Fact]
    public void AutoArm_enters_recovering_on_sustained_imbalance()
    {
        var engine = new FeedforwardEngine(); var st = new ColumnState();
        AdvisoryResult res = engine.Tick(Cfg(autoArm:true), Imbalanced(), st, DateTime.UtcNow);
        for (int i = 0; i < 6; i++) res = engine.Tick(Cfg(autoArm:true), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Recovering, res.Mode);
        Assert.Equal(0.0, res.FeedRecommendedSp);
        var r = res.Streams.First(s => s.Key == "R");
        var p = res.Streams.First(s => s.Key == "P");
        Assert.Equal(1100.0, r.RecommendedSp);
        Assert.Equal(0.0, p.RecommendedSp);
        Assert.False(p.Valid);
    }

    [Fact]
    public void ManualArm_required_when_autoArm_false()
    {
        var engine = new FeedforwardEngine(); var st = new ColumnState();
        for (int i = 0; i < 6; i++) engine.Tick(Cfg(autoArm:false), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Normal, st.Mode);
        st.OperatorArmed = true;
        var res = engine.Tick(Cfg(autoArm:false), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Recovering, res.Mode);
    }

    [Fact]
    public void Recovers_then_returns_to_normal()
    {
        var engine = new FeedforwardEngine(); var st = new ColumnState();
        for (int i = 0; i < 6; i++) engine.Tick(Cfg(autoArm:true), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Recovering, st.Mode);
        AdvisoryResult res = null!;
        for (int i = 0; i < 10; i++) res = engine.Tick(Cfg(autoArm:true), Balanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Normal, res.Mode);
    }

    [Fact]
    public void Cancel_returns_to_normal_immediately()
    {
        var engine = new FeedforwardEngine(); var st = new ColumnState();
        for (int i = 0; i < 6; i++) engine.Tick(Cfg(autoArm:true), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Recovering, st.Mode);
        st.OperatorCancel = true;
        var res = engine.Tick(Cfg(autoArm:true), Imbalanced(), st, DateTime.UtcNow);
        Assert.Equal(ColumnMode.Normal, res.Mode);
    }
}