using Elwig.Helpers;
using Elwig.Models.Entities;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Threading.Tasks;

namespace Elwig.Models.Dtos {
    public class CreditNoteData : DataTable<CreditNoteRow> {

        private static readonly (string, string, string?)[] FieldNames = new[] {
            ("", "", (string?)null), // TODO
        };

        private readonly int Year;
        private readonly int? TgNr;
        private readonly int? AvNr;
        private readonly int? MgNr;

        private CreditNoteData(IEnumerable<CreditNoteRow> rows, int year, int? tgnr, int? avnr = null, int? mgnr = null) :
            base($"Traubengutschrift {year}/{tgnr}", rows, FieldNames) {
            Year = year;
            TgNr = tgnr;
            AvNr = avnr;
            MgNr = mgnr;
        }

        public static async Task<IDictionary<int, CreditNoteData>> ForPaymentVariant(DbSet<CreditNoteRowSingle> table, int year, int avnr) {
            return (await FromDbSet(table, year, avnr))
                .GroupBy(
                    r => new { r.Year, r.AvNr, r.MgNr, r.TgNr, r.DId, r.DPNr },
                    (k, g) => new CreditNoteRow(g))
                .GroupBy(
                    r => new { r.Year, r.AvNr, r.MgNr, r.TgNr },
                    (k, g) => new CreditNoteData(g, k.Year, k.TgNr, mgnr: k.MgNr))
                .ToDictionary(d => d.MgNr ?? 0);
        }

        private static async Task<IEnumerable<CreditNoteRowSingle>> FromDbSet(DbSet<CreditNoteRowSingle> table, int? year = null, int? avnr = null, int? mgnr = null) {
            var y = year?.ToString() ?? "NULL";
            var v = avnr?.ToString() ?? "NULL";
            var m = mgnr?.ToString() ?? "NULL";
            return await table.FromSqlRaw($"""
                SELECT d.year, c.tgnr, p.avnr, d.mgnr, d.did, d.lsnr, d.dpnr, b.bktnr, d.sortid, b.discr, b.value, p.price, p.amount,
                       v.name AS variant, a.name AS attribute, q.name AS quality_level, d.oe, d.kmw
                FROM v_delivery d
                    JOIN wine_variety v ON d.sortid = v.sortid
                    LEFT JOIN wine_attribute a ON a.attrid = d.attrid
                    JOIN wine_quality_level q ON q.qualid = d.qualid
                    LEFT JOIN delivery_part_bucket b ON (b.year, b.did, b.dpnr) = (d.year, d.did, d.dpnr)
                    LEFT JOIN payment_delivery_part_bucket p ON (p.year, p.did, p.dpnr, p.bktnr) = (b.year, b.did, b.dpnr, b.bktnr)
                    LEFT JOIN credit c ON (c.year, c.avnr, c.mgnr) = (d.year, p.avnr, d.mgnr)
                WHERE b.value > 0 AND (d.year = {y} OR {y} IS NULL) AND (p.avnr = {v} OR {v} IS NULL OR p.avnr IS NULL) AND (d.mgnr = {m} OR {m} IS NULL)
                ORDER BY d.year, p.avnr, d.mgnr, d.lsnr, d.dpnr
                """).ToListAsync();
        }
    }

    public class CreditNoteRow {

        public int Year;
        public int? TgNr;
        public int AvNr;
        public int MgNr;

        public string LsNr;
        public int DPNr;
        public string Variant;
        public string? Attribute;
        public string[] Modifiers;
        public string QualityLevel;
        public (double Oe, double Kmw) Gradation;
        public (string Name, int Value, decimal? Price, decimal? Amount)[] Buckets;

        public CreditNoteRow(IEnumerable<CreditNoteRowSingle> rows) {
            var f = rows.First();
            Year = f.Year;
            TgNr = f.TgNr;
            MgNr = f.MgNr;

            LsNr = f.LsNr;
            DPNr = f.DPNr;
            Variant = f.Variant;
            Attribute = f.Attribute;
            Modifiers = Array.Empty<string>();  // TODO
            QualityLevel = f.QualityLevel;
            Gradation = (f.Oe, f.Kmw);
            Buckets = rows
                .Where(b => b.Value > 0)
                .OrderByDescending(b => b.BktNr)
                .Select(b => (b.Discr == "_" ? "ungeb." : $"geb. {f.SortId}{b.Discr}", b.Value,
                              b.Price != null ? (decimal?)Utils.DecFromDb((long)b.Price, 0) : null,
                              b.Amount != null ? (decimal?)Utils.DecFromDb((long)b.Amount, 0) : null))
                .ToArray();
        }
    }

    [Keyless]
    public class CreditNoteRowSingle {
        [Column("year")]
        public int Year { get; set; }
        [Column("tgnr")]
        public int? TgNr { get; set; }
        [Column("avnr")]
        public int? AvNr { get; set; }
        [Column("mgnr")]
        public int MgNr { get; set; }
        [Column("did")]
        public int DId { get; set; }
        [Column("lsnr")]
        public string LsNr { get; set; }
        [Column("dpnr")]
        public int DPNr { get; set; }
        [Column("bktnr")]
        public int BktNr { get; set; }
        [Column("sortid")]
        public string SortId { get; set; }
        [Column("discr")]
        public string Discr { get; set; }
        [Column("value")]
        public int Value { get; set; }
        [Column("price")]
        public long? Price { get; set; }
        [Column("amount")]
        public long? Amount { get; set; }
        [Column("variant")]
        public string Variant { get; set; }
        [Column("attribute")]
        public string? Attribute { get; set; }
        [Column("quality_level")]
        public string QualityLevel { get; set; }
        [Column("oe")]
        public double Oe { get; set; }
        [Column("kmw")]
        public double Kmw { get; set; }
    }
}