using System.Globalization;
using MeterVault.Core.Analysis;
using MeterVault.Core.Analysis.Costing;
using MeterVault.Core.Analysis.Coverage;
using MeterVault.Core.Analysis.Totals;
using MeterVault.Core.Domain;
using MeterVault.Infrastructure.Analysis;

namespace MeterVault.Integration.Tests.Analysis;

/// <summary>
/// Builders for the pure tests of the shared analysis components: real buckets from the period resolver and the bucket
/// planner (Berlin, frozen clock), values, reader series, priced cost figures, and a culture scope — the machine running
/// the tests may be German, and the components format for the reader.
/// </summary>
internal static class AnalysisUiTestData
{
    public static readonly TimeZoneInfo Berlin = TimeZoneInfo.FindSystemTimeZoneById("Europe/Berlin");

    /// <summary>Long after every range the tests use, so custom ranges resolve as complete.</summary>
    public static readonly DateTimeOffset FarFuture = new(2040, 1, 1, 0, 0, 0, TimeSpan.Zero);

    /// <summary>19 September 2026, 14:37 Berlin.</summary>
    public static readonly DateTimeOffset Now = new DateTimeOffset(2026, 9, 19, 14, 37, 0, TimeSpan.FromHours(2)).ToUniversalTime();

    public static DateOnly D(int year, int month, int day) => new(year, month, day);

    public static ResolvedPeriod Range(DateOnly first, DateOnly last) =>
        PeriodResolver.Resolve(PeriodPreset.Custom, first, last, FarFuture, Berlin);

    public static IReadOnlyList<AnalysisBucket> Buckets(DateOnly first, DateOnly last, BucketSize size = BucketSize.Month) =>
        BucketPlanner.Plan(Range(first, last), size).Buckets;

    public static BucketValue Available(double value, Provenance provenance = Provenance.Measured) => BucketValue.Available(value, provenance);

    public static BucketValue Partial(double value) =>
        new(value, BucketStatus.Partial, Provenance.Measured, ValueIssue.PartialCoverage);

    public static BucketValue Missing() => BucketValue.Missing();

    /// <summary>A physical meter's series in kWh with its total and, optionally, a comparison.</summary>
    public static AnalysisSeries Series(
        int meterId,
        string name,
        IReadOnlyList<BucketValue> values,
        BucketValue? total = null,
        QuantityKind kind = QuantityKind.Consumption,
        SeriesComparison? comparison = null) =>
        new(SeriesKey.ForMeter(meterId, 1, "kWh"), name, SeriesBasis.Physical, kind, "kWh", values, total ?? Available(values.Sum(v => v.Value ?? 0)), IsAdditive: true)
        {
            Comparison = comparison,
        };

    public static SeriesComparison Comparison(IReadOnlyList<BucketValue> values, BucketValue total, Change change) =>
        new(values, total, MatchedCoverageResult.NotComparable, null, null, change);

    /// <summary>
    /// One energy type's bill line priced over <paramref name="buckets"/> at <paramref name="price"/> €/kWh from
    /// <paramref name="priceFrom"/> (no tariff at all when null), with <paramref name="amount"/> kWh per month.
    /// </summary>
    public static CostResult Priced(IReadOnlyList<AnalysisBucket> buckets, double amount, double? price, DateOnly? priceFrom = null)
    {
        Tariff[] tariffs = price is { } value
            ? [new Tariff
            {
                Id = 1,
                ScopeType = TariffScope.EnergyType,
                ScopeId = 1,
                Component = TariffComponent.UnitPrice,
                Value = value,
                Unit = "EUR/kWh",
                ValidFrom = priceFrom ?? D(2000, 1, 1),
            }]
            : [];
        var quantities = CostCalculator.Parts(buckets).Select(p => CostQuantity.Known(p, amount)).ToList();
        var line = new CostLine(10, 1, BillLineKind.UnitPrice, "kWh", quantities);
        return CostCalculator.Calculate(new CostRequest(buckets, D(2039, 12, 31), TariffBook.Create(tariffs, "EUR"), [line]));
    }

    /// <summary>Runs <paramref name="body"/> with <paramref name="culture"/> as the formatting and the UI culture.</summary>
    public static T In<T>(string culture, Func<T> body)
    {
        var format = CultureInfo.CurrentCulture;
        var ui = CultureInfo.CurrentUICulture;
        try
        {
            CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo(culture);
            CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo(culture);
            return body();
        }
        finally
        {
            CultureInfo.CurrentCulture = format;
            CultureInfo.CurrentUICulture = ui;
        }
    }

    public static void In(string culture, Action body) => In(culture, () =>
    {
        body();
        return 0;
    });
}