using App.Core.Entities.Maintenance;
using App.Core.Services.Kpi;

namespace App.Core.Tests.Kpi;

public class KpiCalculatorTests
{
    [Fact]
    public void ComputeMtbfHours_LessThanTwoFailures_ReturnsNull()
    {
        var timestamps = new List<DateTime> { new(2026, 1, 1) };

        Assert.Null(KpiCalculator.ComputeMtbfHours(timestamps));
        Assert.Null(KpiCalculator.ComputeMtbfHours(new List<DateTime>()));
    }

    [Fact]
    public void ComputeMtbfHours_AveragesIntervalsBetweenFailures()
    {
        // Pannes le 1er, le 3 (48h après) et le 8 (120h après) -> moyenne (48+120)/2 = 84h.
        var timestamps = new List<DateTime>
        {
            new(2026, 1, 1),
            new(2026, 1, 3),
            new(2026, 1, 8),
        };

        var mtbf = KpiCalculator.ComputeMtbfHours(timestamps);

        Assert.Equal(84, mtbf);
    }

    [Fact]
    public void ComputeMttrHours_NoCompletedCorrective_ReturnsNull()
    {
        var workOrders = new List<WorkOrder>
        {
            new() { Type = WorkOrderType.Corrective, Status = WorkOrderStatus.InProgress, CreatedAtUtc = DateTime.UtcNow, MachineId = 1, ScheduledDate = DateOnly.FromDateTime(DateTime.UtcNow) },
        };

        Assert.Null(KpiCalculator.ComputeMttrHours(workOrders));
    }

    [Fact]
    public void ComputeMttrHours_AveragesRepairDuration()
    {
        var created = new DateTime(2026, 1, 1, 8, 0, 0, DateTimeKind.Utc);
        var workOrders = new List<WorkOrder>
        {
            new()
            {
                Type = WorkOrderType.Corrective,
                Status = WorkOrderStatus.Done,
                MachineId = 1,
                ScheduledDate = DateOnly.FromDateTime(created),
                CreatedAtUtc = created,
                CompletedAtUtc = created.AddHours(4),
            },
            new()
            {
                Type = WorkOrderType.Corrective,
                Status = WorkOrderStatus.Done,
                MachineId = 1,
                ScheduledDate = DateOnly.FromDateTime(created),
                CreatedAtUtc = created,
                CompletedAtUtc = created.AddHours(8),
            },
        };

        Assert.Equal(6, KpiCalculator.ComputeMttrHours(workOrders));
    }

    [Fact]
    public void ComputeAvailabilityPercent_NullInputs_ReturnsNull()
    {
        Assert.Null(KpiCalculator.ComputeAvailabilityPercent(null, 5));
        Assert.Null(KpiCalculator.ComputeAvailabilityPercent(5, null));
    }

    [Fact]
    public void ComputeAvailabilityPercent_ComputesClassicFormula()
    {
        // MTBF=90, MTTR=10 -> 90/(90+10) = 90%
        var availability = KpiCalculator.ComputeAvailabilityPercent(90, 10);

        Assert.Equal(90.0, availability);
    }

    [Fact]
    public void ComputeMaintenanceCost_SumsPartsAndLabor()
    {
        var parts = new List<(decimal UnitPrice, double Quantity)>
        {
            (10.00m, 3),  // 30
            (5.50m, 2),   // 11
        };

        var cost = KpiCalculator.ComputeMaintenanceCost(parts, laborCost: 100m);

        Assert.Equal(141.00m, cost);
    }

    [Fact]
    public void ComputePreventiveComplianceRatePercent_NoClosedOrders_ReturnsNull()
    {
        var workOrders = new List<WorkOrder>
        {
            new() { Type = WorkOrderType.Preventive, Status = WorkOrderStatus.ToDo, MachineId = 1, ScheduledDate = new DateOnly(2026, 1, 1), CreatedAtUtc = DateTime.UtcNow },
        };

        Assert.Null(KpiCalculator.ComputePreventiveComplianceRatePercent(workOrders));
    }

    [Fact]
    public void ComputePreventiveComplianceRatePercent_CountsOnTimeVsLate()
    {
        var workOrders = new List<WorkOrder>
        {
            // Clôturé avant échéance -> dans les temps
            new()
            {
                Type = WorkOrderType.Preventive, Status = WorkOrderStatus.Done, MachineId = 1,
                ScheduledDate = new DateOnly(2026, 1, 10), CreatedAtUtc = DateTime.UtcNow,
                CompletedAtUtc = new DateTime(2026, 1, 9),
            },
            // Clôturé après échéance -> en retard
            new()
            {
                Type = WorkOrderType.Preventive, Status = WorkOrderStatus.Done, MachineId = 1,
                ScheduledDate = new DateOnly(2026, 1, 10), CreatedAtUtc = DateTime.UtcNow,
                CompletedAtUtc = new DateTime(2026, 1, 15),
            },
            // Curatif : ignoré du calcul
            new()
            {
                Type = WorkOrderType.Corrective, Status = WorkOrderStatus.Done, MachineId = 1,
                ScheduledDate = new DateOnly(2026, 1, 10), CreatedAtUtc = DateTime.UtcNow,
                CompletedAtUtc = new DateTime(2026, 1, 20),
            },
        };

        var rate = KpiCalculator.ComputePreventiveComplianceRatePercent(workOrders);

        Assert.Equal(50.0, rate);
    }
}