using Fitness_core_BE.Models;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;

namespace Fitness_core_BE
{
    // Per-tenant database: one gym's own operational data (staff, memberships, invoices,
    // access control, attendance, ...). One instance of this context per resolved TenantId
    // -- see Infra/Tenancy/TenantConnectionResolver.cs. Row-split entities (MealPlan/
    // WorkoutPlan family, PaymentTransactions) hold this tenant's own client-authored plans
    // / member payments here -- CentralDbContext holds the same entity types for admin
    // templates / platform-billing rows.
    public class TenantDbContext : DbContext
    {
        public TenantDbContext(DbContextOptions<TenantDbContext> options) : base(options) { }

        // The local anchor every tenant-scoped Customer-referencing table FKs to instead of
        // the central Customer.CusId directly (EF/MySQL can't enforce a FK across two
        // separate connections).
        public DbSet<TenantCustomerLink> TenantCustomerLink => Set<TenantCustomerLink>();

        // Staff & RBAC
        public DbSet<Staff> Staff => Set<Staff>();
        public DbSet<StaffPayRate> StaffPayRates => Set<StaffPayRate>();
        public DbSet<StaffPayment> StaffPayments => Set<StaffPayment>();
        public DbSet<GymRole> GymRoles => Set<GymRole>();
        public DbSet<GymRolePermission> GymRolePermissions => Set<GymRolePermission>();

        // Memberships
        public DbSet<CustomerPlan> CustomerPlans => Set<CustomerPlan>();
        public DbSet<CustomerSubscription> CustomerSubscriptions => Set<CustomerSubscription>();
        public DbSet<SubscriptionMember> SubscriptionMembers => Set<SubscriptionMember>();
        public DbSet<SubscriptionInstallment> SubscriptionInstallments => Set<SubscriptionInstallment>();
        public DbSet<CustomerSubItem> CustomerSubItems => Set<CustomerSubItem>();
        public DbSet<CustomerInvoice> CustomerInvoices => Set<CustomerInvoice>();
        public DbSet<CustomerInvoiceItem> CustomerInvoiceItems => Set<CustomerInvoiceItem>();
        public DbSet<CustomerCards> CustomerCards => Set<CustomerCards>();
        // Row-split: only rows with FK_CustomerInvoiceId set (member payments) live here --
        // platform billing payments (FK_ClientInvoiceId set) live in CentralDbContext instead.
        public DbSet<PaymentTransaction> PaymentTransactions => Set<PaymentTransaction>();
        public DbSet<LedgerEntry> LedgerEntries => Set<LedgerEntry>();
        public DbSet<ClientTerms> ClientTerms => Set<ClientTerms>();
        public DbSet<CustomerTermsAcceptance> CustomerTermsAcceptances => Set<CustomerTermsAcceptance>();

        // Access control & devices
        public DbSet<AccessDevice> AccessDevices => Set<AccessDevice>();
        public DbSet<AccessDeviceBinding> AccessDeviceBindings => Set<AccessDeviceBinding>();
        public DbSet<AccessProfile> AccessProfiles => Set<AccessProfile>();
        public DbSet<UnlinkedDeviceEnrollment> UnlinkedDeviceEnrollments => Set<UnlinkedDeviceEnrollment>();
        public DbSet<CustomerAccess> CustomerAccess => Set<CustomerAccess>();
        // Agent/PairingCode moved to CentralDbContext -- see its DbSet comment. FKAgentId on
        // AccessDevice below stays a plain scalar column (unenforced cross-schema reference).
        public DbSet<DeviceCommand> DeviceCommands => Set<DeviceCommand>();
        public DbSet<Attendance> Attendances => Set<Attendance>();

        // Client-authored (non-template) meal/workout plans + assignment join tables
        public DbSet<MealPlan> MealPlans => Set<MealPlan>();
        public DbSet<Meal> Meal => Set<Meal>();
        public DbSet<CustomerMeal> CustomerMeals => Set<CustomerMeal>();
        public DbSet<WorkoutPlan> WorkoutPlans => Set<WorkoutPlan>();
        public DbSet<WorkoutItem> WorkoutItems => Set<WorkoutItem>();
        public DbSet<WorkoutExercise> WorkoutExercises => Set<WorkoutExercise>();
        public DbSet<CustomerWorkout> CustomerWorkouts => Set<CustomerWorkout>();
        public DbSet<CustomerWorkoutExerciseCompletion> CustomerWorkoutExerciseCompletions => Set<CustomerWorkoutExerciseCompletion>();

        // Multi-facility session booking + RFID time-bank cards (pool/court/class booking, one
        // per club since single-tenant), and access-zone/device-scoping -- Facility merges what
        // used to be two separate concepts (bookable capacity + access zone), see Models/Facility.cs.
        public DbSet<Facility> Facilities => Set<Facility>();
        public DbSet<FacilitySession> FacilitySessions => Set<FacilitySession>();
        public DbSet<Booking> Bookings => Set<Booking>();
        public DbSet<TimeBankCard> TimeBankCards => Set<TimeBankCard>();
        public DbSet<TimeBankCardUsageLog> TimeBankCardUsageLogs => Set<TimeBankCardUsageLog>();
        public DbSet<CustomerPlanFacility> CustomerPlanFacilities => Set<CustomerPlanFacility>();

        // Booking-scoped RFID tag inventory (assigned to a Booking at check-in, released at
        // Complete/no-show sweep) -- see Models/RfidTag.cs. Not to be confused with
        // TimeBankCard's own, unrelated RfidTagId string field.
        public DbSet<RfidTag> RfidTags => Set<RfidTag>();

        // Snapshot receipt created whenever a Booking's payment is recorded -- see
        // Models/BookingInvoice.cs. Deliberately separate from CustomerInvoice (membership-only).
        public DbSet<BookingInvoice> BookingInvoices => Set<BookingInvoice>();

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            // Central-only entity types must never be part of this model at all. Ignoring
            // individual navigations (below) isn't enough on its own: an unignored central
            // collection nav elsewhere (e.g. Customer.CustomerSubscriptions/.CustomerMeals/
            // .CustomerWorkouts, Client.ClientBusinesses) pulls the whole
            // type into this context's model via EF's reachability-based discovery, which then
            // invents a *second*, bogus shadow-FK relationship (e.g. a phantom
            // "CustomerCusId" column) between that type and whatever tenant entity also
            // happens to have its own real FK to it (e.g. CustomerSubscription, CustomerMeal,
            // CustomerWorkout via TenantCustomerLink) -- breaking every query against that
            // tenant entity with "Unknown column" once EF tries to select the phantom column.
            // Blanket-ignoring the type at the root closes every such path at once, including
            // ones not yet hit by a specific per-navigation Ignore below.
            modelBuilder.Ignore<Customer>();
            modelBuilder.Ignore<Client>();
            // These were previously missing from this list. On separate physical databases
            // (GYM's production layout) the gap was harmless -- the schema was hand-maintained/
            // EnsureCreated, so these reachability-discovered phantom entities never actually
            // got materialized as tables. Generating a real migration from this context's model
            // (both contexts now share one DB) surfaced it immediately: each of these got its
            // own duplicate table (usually singular-named, since they have no explicit DbSet
            // here) alongside CentralDbContext's real, correctly-named one. Ignoring them here
            // closes every reachability path at once, same as Customer/Client/WorkoutCategory
            // above.
            modelBuilder.Ignore<Admin>();
            modelBuilder.Ignore<User>();
            modelBuilder.Ignore<Ticket>();
            modelBuilder.Ignore<TicketCategory>();
            modelBuilder.Ignore<TicketMessage>();
            modelBuilder.Ignore<UserDocument>();
            modelBuilder.Ignore<DocumentTypes>();
            modelBuilder.Ignore<ClientPackage>();
            modelBuilder.Ignore<ClientCard>();
            modelBuilder.Ignore<ClientBusiness>();
            modelBuilder.Ignore<ClientSubscription>();
            modelBuilder.Ignore<ClientInvoice>();
            modelBuilder.Ignore<ClientInvoiceItem>();
            modelBuilder.Ignore<NavItem>();
            modelBuilder.Ignore<CusWeightLossProgress>();
            modelBuilder.Ignore<CustomerTarget>();
            // Plan categories are admin-authored and live centrally (CentralDbContext owns
            // and seeds them; WorkoutRepository/MealRepository read and write them via
            // _central). Left un-ignored, WorkoutPlan.WorkoutCategory / MealPlan.MealCategory
            // drag the type into this model, which materialises an empty tenant-side
            // "workoutcategory"/"mealcategory" table AND a real FK from the plan table to it
            // -- so creating a gym's own plan fails the constraint against a table that is
            // never populated.
            modelBuilder.Ignore<WorkoutCategory>();
            modelBuilder.Ignore<MealCategory>();
            // Agent/PairingCode now live only in CentralDbContext (see its DbSet comment).
            modelBuilder.Ignore<Agent>();
            modelBuilder.Ignore<PairingCode>();

            // Central-pointing navigation properties this context can't resolve -- the FK
            // scalar column stays (it's still real data, just not a same-context relationship
            // once central/tenant are physically separate DBs).
            modelBuilder.Entity<Attendance>().Ignore(a => a.Client);
            modelBuilder.Entity<Attendance>().Ignore(a => a.User);
            modelBuilder.Entity<AccessProfile>().Ignore(p => p.Client);
            modelBuilder.Entity<AccessProfile>().Ignore(p => p.User);
            modelBuilder.Entity<AccessDevice>().Ignore(d => d.Client);
            modelBuilder.Entity<CustomerAccess>().Ignore(c => c.Customer);
            // A followed/assigned plan can be an admin-authored template (central) or this
            // gym's own plan (tenant) -- GetWorkoutPlanListAsync serves customers the central
            // templates. An enforced FK to the tenant plan table therefore can't hold: it
            // rejects every follow of a template. The scalar id stays; which bucket it points
            // at is resolved in the repository, the same way TenantCustomerLink ids are.
            modelBuilder.Entity<CustomerWorkout>().Ignore(cw => cw.WorkoutPlan);
            modelBuilder.Entity<CustomerMeal>().Ignore(cm => cm.MealPlan);
            modelBuilder.Entity<DeviceCommand>().Ignore(c => c.Client);
            modelBuilder.Entity<CustomerInvoice>().Ignore(i => i.Client);
            modelBuilder.Entity<CustomerInvoice>().Ignore(i => i.User);
            modelBuilder.Entity<CustomerPlan>().Ignore(p => p.Client);
            modelBuilder.Entity<CustomerTermsAcceptance>().Ignore(t => t.Client);
            modelBuilder.Entity<LedgerEntry>().Ignore(l => l.Client);
            modelBuilder.Entity<GymRole>().Ignore(r => r.Client);
            modelBuilder.Entity<Staff>().Ignore(s => s.User);
            modelBuilder.Entity<Staff>().Ignore(s => s.Client);
            modelBuilder.Entity<MealPlan>().Ignore(p => p.Client);
            modelBuilder.Entity<WorkoutPlan>().Ignore(p => p.Client);
            modelBuilder.Entity<PaymentTransaction>().Ignore(p => p.Client);
            modelBuilder.Entity<PaymentTransaction>().Ignore(p => p.Customer);
            modelBuilder.Entity<PaymentTransaction>().Ignore(p => p.ClientInvoice);

            // Row-split entities: real DbSets in both contexts (see class comment), but on one
            // shared database only one context's migration should physically create the table.
            // CentralDbContext owns creation here (it also seeds admin-authored templates into
            // MealPlan/WorkoutPlan* via HasData) -- ExcludeFromMigrations lets this context keep
            // querying/writing these tables normally without generating a conflicting duplicate
            // CreateTable for them.
            modelBuilder.Entity<MealPlan>().ToTable(tb => tb.ExcludeFromMigrations());
            modelBuilder.Entity<Meal>().ToTable(tb => tb.ExcludeFromMigrations());
            modelBuilder.Entity<WorkoutPlan>().ToTable(tb => tb.ExcludeFromMigrations());
            modelBuilder.Entity<WorkoutItem>().ToTable(tb => tb.ExcludeFromMigrations());
            modelBuilder.Entity<WorkoutExercise>().ToTable(tb => tb.ExcludeFromMigrations());
            modelBuilder.Entity<PaymentTransaction>().ToTable(tb => tb.ExcludeFromMigrations());

            // Central-pointing scalar FKs on the new booking entities -- same pattern as every
            // other .Client nav in this context (FKClientId column stays, real relationship
            // doesn't, since Client lives only in CentralDbContext).
            modelBuilder.Entity<Facility>().Ignore(f => f.Client);
            modelBuilder.Entity<FacilitySession>().Ignore(s => s.Client);
            modelBuilder.Entity<Booking>().Ignore(b => b.Client);
            modelBuilder.Entity<BookingInvoice>().Ignore(i => i.Client);
            modelBuilder.Entity<TimeBankCard>().Ignore(t => t.Client);
            modelBuilder.Entity<TimeBankCardUsageLog>().Ignore(l => l.Client);

            // A session's capacity is enforced by counting non-cancelled bookings against it at
            // booking time, not by a unique index -- multiple guests/members can share one slot
            // up to Facility.DefaultCapacity. What must stay unique is a member double-booking
            // the same session twice. FKFacilitySessionId is null for every AdHoc booking, and
            // MySQL/InnoDB never treats two NULLs as duplicates in a unique index, so this index
            // is naturally a no-op for AdHoc bookings -- their own overlap-vs-NumberOfUnits check
            // lives in BookingRepository.GetOverlappingAdhocBookingCountAsync instead.
            modelBuilder.Entity<Booking>()
                .HasIndex(b => new { b.FKFacilitySessionId, b.FKCustomerId })
                .IsUnique()
                .HasFilter("`FKCustomerId` IS NOT NULL AND `Status` <> 'Cancelled'");

            modelBuilder.Entity<FacilitySession>()
                .HasIndex(s => new { s.FKFacilityId, s.StartTime });

            modelBuilder.Entity<TimeBankCard>()
                .HasIndex(t => t.RfidTagId)
                .IsUnique();

            modelBuilder.Entity<Booking>()
                .HasIndex(b => b.OtpCode);

            // A customer can appear only once per subscription; installments are unique per position.
            modelBuilder.Entity<SubscriptionMember>()
                .HasIndex(sm => new { sm.FKSubscriptionId, sm.FKCustomerId })
                .IsUnique();
            modelBuilder.Entity<SubscriptionInstallment>()
                .HasIndex(si => new { si.FKSubscriptionId, si.InstallmentNo })
                .IsUnique();

            // An exercise can only be marked completed once per customer workout.
            modelBuilder.Entity<CustomerWorkoutExerciseCompletion>()
                .HasIndex(c => new { c.FKCustomerWorkoutId, c.FKWorkoutExerciseId })
                .IsUnique();

            modelBuilder.Entity<AccessProfile>()
                .HasIndex(p => new { p.FKClientId, p.FKUserId })
                .IsUnique();

            modelBuilder.Entity<AccessDeviceBinding>()
                .HasIndex(b => new { b.FKAccessProfileId, b.FKDeviceId })
                .IsUnique();
            modelBuilder.Entity<AccessDeviceBinding>()
                .HasIndex(b => new { b.FKDeviceId, b.DeviceEmployeeNo })
                .IsUnique();
            modelBuilder.Entity<AccessDeviceBinding>()
                .HasOne(b => b.AccessProfile).WithMany(p => p.DeviceBindings)
                .HasForeignKey(b => b.FKAccessProfileId).OnDelete(DeleteBehavior.Cascade);
            modelBuilder.Entity<AccessDeviceBinding>()
                .HasOne(b => b.AccessDevice).WithMany()
                .HasForeignKey(b => b.FKDeviceId).OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<AccessDevice>()
                .HasIndex(d => new { d.FKClientId, d.HardwareId })
                .IsUnique();
            // Agent now lives centrally -- FKAgentId stays a real column, just not a
            // same-context FK anymore (same pattern as every other central-pointing scalar).
            modelBuilder.Entity<AccessDevice>().Ignore(d => d.Agent);

            // One device per facility for now -- see AccessDevice.FKFacilityId comment. Lifting
            // this to many-devices-per-facility later is just dropping this index.
            modelBuilder.Entity<AccessDevice>()
                .HasIndex(d => d.FKFacilityId)
                .IsUnique()
                .HasFilter("`FKFacilityId` IS NOT NULL");

            modelBuilder.Entity<CustomerPlanFacility>()
                .HasIndex(pf => new { pf.FKCustomerPlanId, pf.FKFacilityId })
                .IsUnique();
            modelBuilder.Entity<CustomerPlanFacility>()
                .HasOne(pf => pf.CustomerPlan).WithMany()
                .HasForeignKey(pf => pf.FKCustomerPlanId).OnDelete(DeleteBehavior.Cascade);
            modelBuilder.Entity<CustomerPlanFacility>()
                .HasOne(pf => pf.Facility).WithMany()
                .HasForeignKey(pf => pf.FKFacilityId).OnDelete(DeleteBehavior.Restrict);

            // RFID tag inventory is per-client; a tag code only needs to be unique within one
            // club's pool.
            modelBuilder.Entity<RfidTag>()
                .HasIndex(t => new { t.FKClientId, t.TagCode })
                .IsUnique();

            // AdHoc bookings share a facility's NumberOfUnits, checked by counting overlapping
            // non-cancelled/non-completed bookings at creation/reschedule time (see
            // BookingRepository.GetOverlappingAdhocBookingCountAsync) rather than a DB
            // constraint -- an exclusion constraint over a time range isn't expressible as a
            // simple unique index, and MySQL/Pomelo has no range-overlap index type. This index
            // just makes that overlap query efficient.
            modelBuilder.Entity<Booking>()
                .HasIndex(b => new { b.FKFacilityId, b.StartTime, b.EndTime });

            modelBuilder.Entity<BookingInvoice>()
                .HasIndex(i => new { i.FKClientId, i.IssuedAt });

            modelBuilder.Entity<UnlinkedDeviceEnrollment>()
                .HasIndex(e => new { e.FKDeviceId, e.DeviceEmployeeNo, e.LinkedAt });

            modelBuilder.Entity<Attendance>()
                .HasIndex(a => a.SourceEventKey)
                .IsUnique();

            modelBuilder.Entity<DeviceCommand>()
                .HasIndex(c => new { c.FKClientId, c.Status, c.NextAttemptAt });
            modelBuilder.Entity<DeviceCommand>()
                .Property(c => c.MaxAttempts)
                .HasDefaultValue(5);

            modelBuilder.Entity<GymRolePermission>()
                .HasKey(p => new { p.FKGymRoleId, p.NavItemKey });
            modelBuilder.Entity<GymRolePermission>().Ignore(p => p.NavItem);
        }
    }

    public class TenantDbContextFactory : IDesignTimeDbContextFactory<TenantDbContext>
    {
        public TenantDbContext CreateDbContext(string[] args)
        {
            var env = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Development";
            var config = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appsettings.json", optional: false)
                .AddJsonFile($"appsettings.{env}.json", optional: true)
                .Build();

            var optionsBuilder = new DbContextOptionsBuilder<TenantDbContext>();
            var connectionString = config.GetConnectionString("DefaultConnection");
            optionsBuilder.UseMySql(connectionString, new MySqlServerVersion(new Version(8, 0, 0)));

            return new TenantDbContext(optionsBuilder.Options);
        }
    }
}