using Microsoft.EntityFrameworkCore;
using PowderCoating.Core.Entities;
using PowderCoating.Core.Enums;

namespace PowderCoating.Infrastructure.Services;

public partial class SeedDataService
{
    /// <summary>
    /// Seeds a realistic 3-month history of vendor bills (Accounts Payable) across four
    /// spending categories — powder orders, consumables/hardware, equipment repairs, and
    /// utilities — with a mix of paid, partially-paid, and open statuses.
    /// </summary>
    /// <remarks>
    /// The seeder constructs a narrative AP ledger covering approximately 90 days so that
    /// the AI Cash Flow Forecast, AR Aging, and Anomaly Detection reports have meaningful
    /// data to analyse from day one of a demo.
    ///
    /// <b>Prerequisites:</b> The method resolves all required accounts by
    /// <see cref="AccountSubType"/> or account number from the company's chart of accounts.
    /// It also resolves vendors by partial name match (e.g., "Prismatic", "Columbia").
    /// If the AP account, the checking account, or at least one vendor is missing the method
    /// returns 0 (skips) rather than throwing, because those dependencies are seeded in
    /// earlier steps which may have failed.
    ///
    /// <b>Local helper <c>AddBill</c>:</b> Assigns the sequential bill number
    /// (format <c>BILL-YYMM-####</c>), stamps <c>CompanyId</c> on the bill and all its
    /// line items, saves, then optionally creates a <see cref="BillPayment"/> with a
    /// sequential payment number (<c>BPMT-YYMM-####</c>).  Separating save-per-bill from
    /// the payment save preserves the FK relationship without needing explicit navigation
    /// property loading.
    ///
    /// <b>Double-entry note:</b> The bill entity itself records the AP credit (via
    /// <c>APAccountId</c>); individual line items carry the debit account (e.g., powder
    /// expense account 5100).  The payment records the AP debit and cash credit (via
    /// <c>BankAccountId</c>).  The seed data mirrors this pattern but does NOT create
    /// journal entry rows — those are handled by the AP payment workflow in production.
    ///
    /// <b>Status timeline:</b>
    /// - Months −3 to −1: bills with matching paid payments (closed AP).
    /// - Current month: open bills (due soon) to populate the AP Aging report.
    /// - One overdue specialty bill (past due date, still open) to trigger the anomaly
    ///   detection feature's "overdue payable" flag.
    ///
    /// Idempotency: returns 0 immediately if any bills exist for the company.
    /// </remarks>
    /// <param name="company">The tenant company to seed bills for.</param>
    /// <returns>The total number of <see cref="Bill"/> records created.</returns>
    private async Task<int> SeedBillsAsync(Company company)
    {
        var existingCount = await _context.Set<Bill>()
            .IgnoreQueryFilters()
            .CountAsync(b => b.CompanyId == company.Id && !b.IsDeleted);

        if (existingCount > 0)
            return 0;

        // ── Account lookups ───────────────────────────────────────────────────
        var apAccount = await _context.Set<Account>()
            .IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted
                && a.AccountSubType == AccountSubType.AccountsPayable);

        var checkingAccount = await _context.Set<Account>()
            .IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted
                && a.AccountSubType == AccountSubType.Checking);

        var powderAccount   = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "5100");
        var consumablesAccount = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "5200");
        var equipRepairsAccount = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6100");
        var utilitiesAccount = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6600");

        if (apAccount == null || checkingAccount == null)
            return 0;

        // ── Vendor lookups ────────────────────────────────────────────────────
        var vendors  = await _context.Set<Vendor>()
            .IgnoreQueryFilters()
            .Where(v => v.CompanyId == company.Id && !v.IsDeleted)
            .ToListAsync();

        var prismatic    = vendors.FirstOrDefault(v => v.CompanyName.Contains("Prismatic")) ?? vendors.FirstOrDefault();
        var columbia     = vendors.FirstOrDefault(v => v.CompanyName.Contains("Columbia"))  ?? vendors.FirstOrDefault();
        var aceHardware  = vendors.FirstOrDefault(v => v.CompanyName.Contains("Ace"))       ?? vendors.FirstOrDefault();
        var fastenal     = vendors.FirstOrDefault(v => v.CompanyName.Contains("Fastenal"))  ?? vendors.FirstOrDefault();
        var fallback     = vendors.FirstOrDefault();

        if (fallback == null)
            return 0;

        var now      = DateTime.UtcNow;
        var prefix   = $"BILL-{now:yy}{now.Month:D2}-";
        var pmtPfx   = $"BPMT-{now:yy}{now.Month:D2}-";
        var seeded   = 0;
        var billSeq  = 1;
        var pmtSeq   = 1;

        // Helper: add a bill and optional payment, save, return bill
        async Task<Bill> AddBill(
            Bill bill, BillPayment? payment = null)
        {
            bill.BillNumber = $"{prefix}{billSeq++:D4}";
            bill.CompanyId  = company.Id;
            foreach (var li in bill.LineItems) { li.CompanyId = company.Id; li.CreatedAt = bill.CreatedAt; }

            await _context.Set<Bill>().AddAsync(bill);
            await _context.SaveChangesAsync();
            seeded++;

            if (payment != null)
            {
                payment.PaymentNumber = $"{pmtPfx}{pmtSeq++:D4}";
                payment.BillId        = bill.Id;
                payment.CompanyId     = company.Id;
                payment.CreatedAt     = payment.PaymentDate;
                await _context.Set<BillPayment>().AddAsync(payment);
                await _context.SaveChangesAsync();
            }

            return bill;
        }

        // ── POWDER ORDERS ─────────────────────────────────────────────────────

        // Month -3: Large powder restock — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "PP-77211",
            VendorId   = (prismatic ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-90),
            DueDate     = now.AddDays(-60),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Quarterly powder restock — month 1",
            SubTotal    = 1_145.00m,
            Total       = 1_145.00m,
            AmountPaid  = 1_145.00m,
            CreatedAt   = now.AddDays(-90),
            LineItems   =
            {
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Matte Black Powder — 50 lbs",     Quantity = 2, UnitPrice = 178.00m, Amount = 356.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Gloss White Powder — 50 lbs",     Quantity = 2, UnitPrice = 165.00m, Amount = 330.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Satin Silver Powder — 25 lbs",    Quantity = 2, UnitPrice = 144.50m, Amount = 289.00m, DisplayOrder = 3 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Masking Tape & Plugs Kit",  Quantity = 1, UnitPrice = 170.00m, Amount = 170.00m, DisplayOrder = 4 }
            }
        }, new BillPayment
        {
            VendorId = (prismatic ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-60),
            Amount        = 1_145.00m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "PP-77211 — paid in full"
        });

        // Month -2: Mid-cycle specialty colors — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "CC-4401",
            VendorId    = (columbia ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-65),
            DueDate     = now.AddDays(-35),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Specialty metallic & candy colors",
            SubTotal    = 986.00m,
            Total       = 986.00m,
            AmountPaid  = 986.00m,
            CreatedAt   = now.AddDays(-65),
            LineItems   =
            {
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Candy Red Metallic — 10 lbs",   Quantity = 3, UnitPrice = 145.00m, Amount = 435.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Chrome Effect Powder — 10 lbs", Quantity = 2, UnitPrice = 168.00m, Amount = 336.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Hammertone Bronze — 10 lbs",    Quantity = 1, UnitPrice = 150.50m, Amount = 150.50m, DisplayOrder = 3 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Ground Straps & Hooks",    Quantity = 1, UnitPrice =  64.50m, Amount =  64.50m, DisplayOrder = 4 }
            }
        }, new BillPayment
        {
            VendorId = (columbia ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-35),
            Amount        = 986.00m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "CC-4401 — paid in full"
        });

        // Month -1: Regular restock — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "PP-83440",
            VendorId    = (prismatic ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-45),
            DueDate     = now.AddDays(-15),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Monthly powder restock",
            SubTotal    = 892.50m,
            Total       = 892.50m,
            AmountPaid  = 892.50m,
            CreatedAt   = now.AddDays(-45),
            LineItems   =
            {
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Matte Black Powder — 25 lbs",   Quantity = 5, UnitPrice =  89.00m, Amount = 445.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Gloss White Powder — 25 lbs",   Quantity = 4, UnitPrice =  86.50m, Amount = 346.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Masking Plugs Assortment", Quantity = 1, UnitPrice = 101.50m, Amount = 101.50m, DisplayOrder = 3 }
            }
        }, new BillPayment
        {
            VendorId = (prismatic ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-15),
            Amount        = 892.50m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "PP-83440 — paid in full"
        });

        // Current month: Open (due soon)
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "PP-88530",
            VendorId    = (prismatic ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-8),
            DueDate     = now.AddDays(22),
            Status      = BillStatus.Open,
            Terms       = "Net 30",
            Memo        = "Current month powder order",
            SubTotal    = 1_050.00m,
            Total       = 1_050.00m,
            AmountPaid  = 0m,
            CreatedAt   = now.AddDays(-8),
            LineItems   =
            {
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Matte Black Powder — 25 lbs",       Quantity = 6, UnitPrice =  89.00m, Amount = 534.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Gloss Red Powder — 10 lbs",         Quantity = 2, UnitPrice = 132.00m, Amount = 264.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Hanging Racks (10-pack)",       Quantity = 2, UnitPrice = 126.00m, Amount = 252.00m, DisplayOrder = 3 }
            }
        });

        // Overdue specialty order
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "CC-5509",
            VendorId    = (columbia ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-50),
            DueDate     = now.AddDays(-5),
            Status      = BillStatus.Open,
            Terms       = "Net 45",
            Memo        = "Specialty colors — overdue",
            SubTotal    = 1_240.00m,
            Total       = 1_240.00m,
            AmountPaid  = 0m,
            CreatedAt   = now.AddDays(-50),
            LineItems   =
            {
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Candy Red Metallic — 10 lbs",   Quantity = 3, UnitPrice = 145.00m, Amount = 435.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Chrome Effect — 10 lbs",        Quantity = 3, UnitPrice = 168.00m, Amount = 504.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = powderAccount?.Id, Description = "Hammertone Bronze — 10 lbs",    Quantity = 2, UnitPrice = 150.50m, Amount = 301.00m, DisplayOrder = 3 }
            }
        });

        // ── CONSUMABLES / HARDWARE ─────────────────────────────────────────────

        // Month -3: Fastenal hardware — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "FST-18822",
            VendorId    = (fastenal ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-85),
            DueDate     = now.AddDays(-55),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Hardware & consumables restock",
            SubTotal    = 412.50m,
            Total       = 412.50m,
            AmountPaid  = 412.50m,
            CreatedAt   = now.AddDays(-85),
            LineItems   =
            {
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "J-Hook Hangers Assortment",       Quantity = 2, UnitPrice = 89.75m, Amount = 179.50m, DisplayOrder = 1 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Masking Caps — Mixed (100-pack)", Quantity = 2, UnitPrice = 60.00m, Amount = 120.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Wire Brushes & Abrasives",        Quantity = 1, UnitPrice = 113.00m, Amount = 113.00m, DisplayOrder = 3 }
            }
        }, new BillPayment
        {
            VendorId = (fastenal ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-55),
            Amount        = 412.50m,
            PaymentMethod = PaymentMethod.Check,
            CheckNumber   = "1082",
            Memo          = "FST-18822 — paid in full"
        });

        // Month -1: Fastenal — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "FST-20041",
            VendorId    = (fastenal ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-40),
            DueDate     = now.AddDays(-10),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Monthly hardware restock",
            SubTotal    = 298.00m,
            Total       = 298.00m,
            AmountPaid  = 298.00m,
            CreatedAt   = now.AddDays(-40),
            LineItems   =
            {
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Sandpaper & Abrasive Pads (assorted)", Quantity = 2, UnitPrice = 74.50m, Amount = 149.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Masking Caps — Small (100-pack)",      Quantity = 2, UnitPrice = 60.00m, Amount = 120.00m, DisplayOrder = 2 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Safety Gloves (12-pair pack)",         Quantity = 1, UnitPrice = 29.00m, Amount =  29.00m, DisplayOrder = 3 }
            }
        }, new BillPayment
        {
            VendorId = (fastenal ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-10),
            Amount        = 298.00m,
            PaymentMethod = PaymentMethod.Check,
            CheckNumber   = "1086",
            Memo          = "FST-20041 — paid in full"
        });

        // Current: Fastenal — Open
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "FST-20441",
            VendorId    = (fastenal ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-7),
            DueDate     = now.AddDays(23),
            Status      = BillStatus.Open,
            Terms       = "Net 30",
            Memo        = "Monthly hardware & fastener restock",
            SubTotal    = 318.75m,
            Total       = 318.75m,
            AmountPaid  = 0m,
            CreatedAt   = now.AddDays(-7),
            LineItems   =
            {
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Hanging Racks & J-Hooks",         Quantity = 1, UnitPrice = 198.75m, Amount = 198.75m, DisplayOrder = 1 },
                new BillLineItem { AccountId = consumablesAccount?.Id, Description = "Masking Caps — Mixed (100-pack)", Quantity = 2, UnitPrice =  60.00m, Amount = 120.00m, DisplayOrder = 2 }
            }
        });

        // ── EQUIPMENT REPAIRS ─────────────────────────────────────────────────

        // Month -3: Sandblaster service — Paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ACE-6901",
            VendorId    = (aceHardware ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-80),
            DueDate     = now.AddDays(-50),
            Status      = BillStatus.Paid,
            Terms       = "Net 30",
            Memo        = "Sandblaster nozzle & cabinet seal replacement",
            SubTotal    = 310.00m,
            Total       = 310.00m,
            AmountPaid  = 310.00m,
            CreatedAt   = now.AddDays(-80),
            LineItems   =
            {
                new BillLineItem { AccountId = equipRepairsAccount?.Id, Description = "Blast Nozzle Tungsten — 3/8\"", Quantity = 2, UnitPrice = 85.00m,  Amount = 170.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = equipRepairsAccount?.Id, Description = "Cabinet Door Seal Kit",         Quantity = 1, UnitPrice = 140.00m, Amount = 140.00m, DisplayOrder = 2 }
            }
        }, new BillPayment
        {
            VendorId = (aceHardware ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-50),
            Amount        = 310.00m,
            PaymentMethod = PaymentMethod.Check,
            CheckNumber   = "1079",
            Memo          = "ACE-6901 — sandblaster parts"
        });

        // Month -1: Oven repair — Partially paid
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ACE-7714",
            VendorId    = (aceHardware ?? fallback).Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-20),
            DueDate     = now.AddDays(10),
            Status      = BillStatus.PartiallyPaid,
            Terms       = "Net 30",
            Memo        = "Oven heating element + shop supplies",
            SubTotal    = 540.00m,
            Total       = 540.00m,
            AmountPaid  = 200.00m,
            CreatedAt   = now.AddDays(-20),
            LineItems   =
            {
                new BillLineItem { AccountId = equipRepairsAccount?.Id, Description = "Oven Heating Element — 240V 5000W", Quantity = 1, UnitPrice = 385.00m, Amount = 385.00m, DisplayOrder = 1 },
                new BillLineItem { AccountId = consumablesAccount?.Id,  Description = "Shop Supplies — Wire Brushes, Sandpaper",       Quantity = 1, UnitPrice = 155.00m, Amount = 155.00m, DisplayOrder = 2 }
            }
        }, new BillPayment
        {
            VendorId = (aceHardware ?? fallback).Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-10),
            Amount        = 200.00m,
            PaymentMethod = PaymentMethod.Check,
            CheckNumber   = "1087",
            Memo          = "ACE-7714 — partial payment"
        });

        // ── UTILITIES (3 months each) ─────────────────────────────────────────

        // Electric — month -3 (paid)
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ELEC-2024-01",
            VendorId    = fallback.Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-90),
            DueDate     = now.AddDays(-75),
            Status      = BillStatus.Paid,
            Terms       = "Due on Receipt",
            Memo        = "Electric — 3 months ago",
            SubTotal    = 592.10m,
            Total       = 592.10m,
            AmountPaid  = 592.10m,
            CreatedAt   = now.AddDays(-90),
            LineItems   =
            {
                new BillLineItem { AccountId = utilitiesAccount?.Id, Description = "Commercial Electric — monthly usage", Quantity = 1, UnitPrice = 592.10m, Amount = 592.10m, DisplayOrder = 1 }
            }
        }, new BillPayment
        {
            VendorId = fallback.Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-75),
            Amount        = 592.10m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "Electric bill — auto pay"
        });

        // Electric — month -2 (paid)
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ELEC-2024-02",
            VendorId    = fallback.Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-60),
            DueDate     = now.AddDays(-45),
            Status      = BillStatus.Paid,
            Terms       = "Due on Receipt",
            Memo        = "Electric — 2 months ago",
            SubTotal    = 618.42m,
            Total       = 618.42m,
            AmountPaid  = 618.42m,
            CreatedAt   = now.AddDays(-60),
            LineItems   =
            {
                new BillLineItem { AccountId = utilitiesAccount?.Id, Description = "Commercial Electric — monthly usage", Quantity = 1, UnitPrice = 618.42m, Amount = 618.42m, DisplayOrder = 1 }
            }
        }, new BillPayment
        {
            VendorId = fallback.Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-45),
            Amount        = 618.42m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "Electric bill — auto pay"
        });

        // Electric — month -1 (paid)
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ELEC-2024-03",
            VendorId    = fallback.Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-30),
            DueDate     = now.AddDays(-15),
            Status      = BillStatus.Paid,
            Terms       = "Due on Receipt",
            Memo        = "Electric — last month",
            SubTotal    = 574.88m,
            Total       = 574.88m,
            AmountPaid  = 574.88m,
            CreatedAt   = now.AddDays(-30),
            LineItems   =
            {
                new BillLineItem { AccountId = utilitiesAccount?.Id, Description = "Commercial Electric — monthly usage", Quantity = 1, UnitPrice = 574.88m, Amount = 574.88m, DisplayOrder = 1 }
            }
        }, new BillPayment
        {
            VendorId = fallback.Id,
            BankAccountId = checkingAccount.Id,
            PaymentDate   = now.AddDays(-15),
            Amount        = 574.88m,
            PaymentMethod = PaymentMethod.BankTransferACH,
            Memo          = "Electric bill — auto pay"
        });

        // Electric — current month (open)
        await AddBill(new Bill
        {
            VendorInvoiceNumber = "ELEC-2024-04",
            VendorId    = fallback.Id,
            APAccountId = apAccount.Id,
            BillDate    = now.AddDays(-2),
            DueDate     = now.AddDays(15),
            Status      = BillStatus.Open,
            Terms       = "Due on Receipt",
            Memo        = "Electric — current month",
            SubTotal    = 601.30m,
            Total       = 601.30m,
            AmountPaid  = 0m,
            CreatedAt   = now.AddDays(-2),
            LineItems   =
            {
                new BillLineItem { AccountId = utilitiesAccount?.Id, Description = "Commercial Electric — monthly usage", Quantity = 1, UnitPrice = 601.30m, Amount = 601.30m, DisplayOrder = 1 }
            }
        });

        return seeded;
    }

    /// <summary>
    /// Seeds recurring direct-expense transactions for the company covering the past ~90 days:
    /// shop rent, natural gas, business insurance, Google Ads / Yelp, software subscriptions,
    /// office supplies, and monthly bank/card-processing fees.
    /// </summary>
    /// <remarks>
    /// Expenses differ from bills in that they are single-line, immediately-paid transactions
    /// (no AP intermediary) — they debit an expense account and credit a cash or credit-card
    /// account directly.  This mirrors the accounting pattern used by the Expenses module.
    ///
    /// <b>Account resolution:</b> Accounts are looked up by account number (e.g., "6500" for
    /// rent, "6600" for utilities) rather than by name so that customised display names do not
    /// break the seeder.  A cascading fallback chain ensures the method still seeds something
    /// useful even if the chart of accounts was partially seeded — the first non-null expense
    /// account found is used as a last-resort category.  If no expense account and no checking
    /// account are found, the method returns 0 and logs nothing (silent skip handled by caller).
    ///
    /// <b>Credit card vs. checking:</b> Advertising and software subscriptions are charged to
    /// the credit card account when one exists (matching real-world business practice).  All
    /// other expenses use the checking account.  If no credit card account was seeded, the
    /// checking account is used as fallback for all categories.
    ///
    /// <b>Local helper <c>AddExp</c>:</b> Assigns a sequential expense number
    /// (format <c>EXP-YYMM-####</c>), saves immediately per expense so that the sequence
    /// counter increments correctly and individual failures can be diagnosed from logs.
    ///
    /// Idempotency: returns 0 immediately if any expense records exist for the company.
    /// </remarks>
    /// <param name="company">The tenant company to seed expenses for.</param>
    /// <returns>The total number of <see cref="Expense"/> records created.</returns>
    private async Task<int> SeedExpensesAsync(Company company)
    {
        var existingCount = await _context.Set<Expense>()
            .IgnoreQueryFilters()
            .CountAsync(e => e.CompanyId == company.Id && !e.IsDeleted);

        if (existingCount > 0)
            return 0;

        // ── Account lookups ───────────────────────────────────────────────────
        var checkingAccount = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountSubType == AccountSubType.Checking);
        var creditCardAccount = await _context.Set<Account>().IgnoreQueryFilters()
            .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountSubType == AccountSubType.CreditCard);

        var utilitiesAcct    = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6600");
        var rentAcct         = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6500");
        var advertisingAcct  = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6000");
        var officeSuppliesAcct = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6800");
        var bankChargesAcct  = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6900");
        var insuranceAcct    = await _context.Set<Account>().IgnoreQueryFilters().FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountNumber == "6200");

        if (checkingAccount == null)
            return 0;

        var fallbackExpense = utilitiesAcct ?? rentAcct ?? advertisingAcct
            ?? await _context.Set<Account>().IgnoreQueryFilters()
               .FirstOrDefaultAsync(a => a.CompanyId == company.Id && !a.IsDeleted && a.AccountType == AccountType.Expense);

        if (fallbackExpense == null)
            return 0;

        var vendors = await _context.Set<Vendor>().IgnoreQueryFilters()
            .Where(v => v.CompanyId == company.Id && !v.IsDeleted).ToListAsync();

        var now     = DateTime.UtcNow;
        var pfx     = $"EXP-{now:yy}{now.Month:D2}-";
        var seeded  = 0;
        var expSeq  = 1;
        var cc      = creditCardAccount ?? checkingAccount;

        async Task AddExp(
            DateTime date, int? vendorId, Account expAcct, Account pmtAcct,
            PaymentMethod method, decimal amount, string memo)
        {
            await _context.Set<Expense>().AddAsync(new Expense
            {
                ExpenseNumber    = $"{pfx}{expSeq++:D4}",
                Date             = date,
                VendorId         = vendorId,
                ExpenseAccountId = expAcct.Id,
                PaymentAccountId = pmtAcct.Id,
                PaymentMethod    = method,
                Amount           = amount,
                Memo             = memo,
                CompanyId        = company.Id,
                CreatedAt        = date
            });
            await _context.SaveChangesAsync();
            seeded++;
        }

        // ── SHOP RENT — 3 months ──────────────────────────────────────────────
        var rentAccount = rentAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-95), null, rentAccount, checkingAccount, PaymentMethod.Check, 2_400.00m, "Shop rent — 3 months ago");
        await AddExp(now.AddDays(-65), null, rentAccount, checkingAccount, PaymentMethod.Check, 2_400.00m, "Shop rent — 2 months ago");
        await AddExp(now.AddDays(-35), null, rentAccount, checkingAccount, PaymentMethod.Check, 2_400.00m, "Shop rent — last month");
        await AddExp(now.AddDays(-3),  null, rentAccount, checkingAccount, PaymentMethod.Check, 2_400.00m, "Shop rent — current month");

        // ── NATURAL GAS — 3 months ────────────────────────────────────────────
        var utilAccount = utilitiesAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-88), null, utilAccount, checkingAccount, PaymentMethod.BankTransferACH, 218.44m, "Natural gas — 3 months ago");
        await AddExp(now.AddDays(-58), null, utilAccount, checkingAccount, PaymentMethod.BankTransferACH, 241.60m, "Natural gas — 2 months ago");
        await AddExp(now.AddDays(-28), null, utilAccount, checkingAccount, PaymentMethod.BankTransferACH, 196.30m, "Natural gas — last month");

        // ── INSURANCE ─────────────────────────────────────────────────────────
        var insAccount = insuranceAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-90), null, insAccount, checkingAccount, PaymentMethod.Check, 785.00m, "Business liability insurance — quarterly premium Q1");
        await AddExp(now.AddDays(-1),  null, insAccount, checkingAccount, PaymentMethod.Check, 785.00m, "Business liability insurance — quarterly premium Q2");

        // ── MARKETING / ADVERTISING ───────────────────────────────────────────
        var adAccount = advertisingAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-80), null, adAccount, cc, PaymentMethod.CreditDebitCard, 150.00m, "Google Ads — local search campaign");
        await AddExp(now.AddDays(-50), null, adAccount, cc, PaymentMethod.CreditDebitCard, 150.00m, "Google Ads — local search campaign");
        await AddExp(now.AddDays(-20), null, adAccount, cc, PaymentMethod.CreditDebitCard, 175.00m, "Google Ads — expanded local campaign");
        await AddExp(now.AddDays(-15), null, adAccount, cc, PaymentMethod.CreditDebitCard,  89.00m, "Yelp advertising — monthly");
        await AddExp(now.AddDays(-5),  null, adAccount, cc, PaymentMethod.CreditDebitCard, 175.00m, "Google Ads — current month");

        // ── SOFTWARE SUBSCRIPTIONS ────────────────────────────────────────────
        var swAccount = officeSuppliesAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-90), null, swAccount, cc, PaymentMethod.CreditDebitCard, 29.00m, "QuickBooks subscription — monthly");
        await AddExp(now.AddDays(-60), null, swAccount, cc, PaymentMethod.CreditDebitCard, 29.00m, "QuickBooks subscription — monthly");
        await AddExp(now.AddDays(-30), null, swAccount, cc, PaymentMethod.CreditDebitCard, 29.00m, "QuickBooks subscription — monthly");
        await AddExp(now.AddDays(-2),  null, swAccount, cc, PaymentMethod.CreditDebitCard, 29.00m, "QuickBooks subscription — monthly");

        // ── OFFICE SUPPLIES ───────────────────────────────────────────────────
        var offAccount = officeSuppliesAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-75), vendors.FirstOrDefault()?.Id, offAccount, cc, PaymentMethod.CreditDebitCard, 63.40m, "Office supplies — printer paper, labels, pens");
        await AddExp(now.AddDays(-8),  vendors.FirstOrDefault()?.Id, offAccount, cc, PaymentMethod.CreditDebitCard, 47.83m, "Office supplies — printer paper, pens, labels");

        // ── BANK FEES ─────────────────────────────────────────────────────────
        var bankAccount = bankChargesAcct ?? fallbackExpense;
        await AddExp(now.AddDays(-85), null, bankAccount, checkingAccount, PaymentMethod.BankTransferACH, 28.50m, "Monthly card processing fees");
        await AddExp(now.AddDays(-55), null, bankAccount, checkingAccount, PaymentMethod.BankTransferACH, 31.20m, "Monthly card processing fees");
        await AddExp(now.AddDays(-25), null, bankAccount, checkingAccount, PaymentMethod.BankTransferACH, 29.80m, "Monthly card processing fees");
        await AddExp(now.AddDays(-3),  null, bankAccount, checkingAccount, PaymentMethod.BankTransferACH, 32.15m, "Monthly card processing fees");

        return seeded;
    }
}