namespace PrayerTracker.Entities

open FSharp.EFCore.OptionConverter
open Microsoft.EntityFrameworkCore
open NodaTime
open System
open System.Collections.Generic

// fsharplint:disable RecordFieldNames MemberNames

(*-- SUPPORT TYPES --*)

/// How as-of dates should (or should not) be displayed with requests
type AsOfDateDisplay =
    /// No as-of date should be displayed
    | NoDisplay
    /// The as-of date should be displayed in the culture's short date format
    | ShortDate
    /// The as-of date should be displayed in the culture's long date format
    | LongDate
with
    
    /// Convert to a DU case from a single-character string
    static member fromCode code =
        match code with
        | "N" -> NoDisplay
        | "S" -> ShortDate
        | "L" -> LongDate
        | _   -> invalidArg "code" $"Unknown code {code}"
    
    /// Convert this DU case to a single-character string
    member this.code =
        match this with
        | NoDisplay -> "N"
        | ShortDate -> "S"
        | LongDate  -> "L"


/// Acceptable e-mail formats
type EmailFormat =
    /// HTML e-mail
    | HtmlFormat
    /// Plain-text e-mail
    | PlainTextFormat
with
    
    /// Convert to a DU case from a single-character string
    static member fromCode code =
        match code with
        | "H" -> HtmlFormat
        | "P" -> PlainTextFormat
        | _   -> invalidArg "code" $"Unknown code {code}"
    
    /// Convert this DU case to a single-character string
    member this.code =
        match this with
        | HtmlFormat      -> "H"
        | PlainTextFormat -> "P"


/// Expiration for requests
type Expiration =
    /// Follow the rules for normal expiration
    | Automatic
    /// Do not expire via rules
    | Manual
    /// Force immediate expiration
    | Forced
with
    
    /// Convert to a DU case from a single-character string
    static member fromCode code =
        match code with
        | "A" -> Automatic
        | "M" -> Manual
        | "F" -> Forced
        | _   -> invalidArg "code" $"Unknown code {code}"
    
    /// Convert this DU case to a single-character string
    member this.code =
        match this with
        | Automatic -> "A"
        | Manual    -> "M"
        | Forced    -> "F"


/// Types of prayer requests
type PrayerRequestType =
    /// Current requests
    | CurrentRequest
    /// Long-term/ongoing request
    | LongTermRequest
    /// Expectant couples
    | Expecting
    /// Praise reports
    | PraiseReport
    /// Announcements
    | Announcement
with
    
    /// Convert to a DU case from a single-character string
    static member fromCode code =
        match code with
        | "C" -> CurrentRequest
        | "L" -> LongTermRequest
        | "E" -> Expecting
        | "P" -> PraiseReport
        | "A" -> Announcement
        | _   -> invalidArg "code" $"Unknown code {code}"
    
    /// Convert this DU case to a single-character string
    member this.code =
        match this with
        | CurrentRequest  -> "C"
        | LongTermRequest -> "L"
        | Expecting       -> "E"
        | PraiseReport    -> "P"
        | Announcement    -> "A"


/// How requests should be sorted
type RequestSort =
    /// Sort by date, then by requestor/subject
    | SortByDate
    /// Sort by requestor/subject, then by date
    | SortByRequestor
with
    
    /// Convert to a DU case from a single-character string
    static member fromCode code =
        match code with
        | "D" -> SortByDate
        | "R" -> SortByRequestor
        | _   -> invalidArg "code" $"Unknown code {code}"
    
    /// Convert this DU case to a single-character string
    member this.code =
        match this with
        | SortByDate      -> "D"
        | SortByRequestor -> "R"


/// EF Core value converters for the discriminated union types above
module Converters =

    open Microsoft.EntityFrameworkCore.Storage.ValueConversion
    open Microsoft.FSharp.Linq.RuntimeHelpers
    open System.Linq.Expressions

    let private asOfFromDU =
        <@ Func<AsOfDateDisplay, string>(fun (x : AsOfDateDisplay) -> x.code) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<AsOfDateDisplay, string>>>

    let private asOfToDU =
        <@ Func<string, AsOfDateDisplay>(AsOfDateDisplay.fromCode) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<string, AsOfDateDisplay>>>
    
    let private emailFromDU =
        <@ Func<EmailFormat, string>(fun (x : EmailFormat) -> x.code) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<EmailFormat, string>>>

    let private emailToDU =
        <@ Func<string, EmailFormat>(EmailFormat.fromCode) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<string, EmailFormat>>>
    
    let private expFromDU =
        <@ Func<Expiration, string>(fun (x : Expiration) -> x.code) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<Expiration, string>>>

    let private expToDU =
        <@ Func<string, Expiration>(Expiration.fromCode) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<string, Expiration>>>
    
    let private sortFromDU =
        <@ Func<RequestSort, string>(fun (x : RequestSort) -> x.code) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<RequestSort, string>>>

    let private sortToDU =
        <@ Func<string, RequestSort>(RequestSort.fromCode) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<string, RequestSort>>>
    
    let private typFromDU =
        <@ Func<PrayerRequestType, string>(fun (x : PrayerRequestType) -> x.code) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<PrayerRequestType, string>>>

    let private typToDU =
        <@ Func<string, PrayerRequestType>(PrayerRequestType.fromCode) @>
        |> LeafExpressionConverter.QuotationToExpression
        |> unbox<Expression<Func<string, PrayerRequestType>>>
    
    /// Conversion between a string and an AsOfDateDisplay DU value
    type AsOfDateDisplayConverter () =
        inherit ValueConverter<AsOfDateDisplay, string> (asOfFromDU, asOfToDU)

    /// Conversion between a string and an EmailFormat DU value
    type EmailFormatConverter () =
        inherit ValueConverter<EmailFormat, string> (emailFromDU, emailToDU)

    /// Conversion between a string and an Expiration DU value
    type ExpirationConverter () =
        inherit ValueConverter<Expiration, string> (expFromDU, expToDU)

    /// Conversion between a string and an AsOfDateDisplay DU value
    type PrayerRequestTypeConverter () =
        inherit ValueConverter<PrayerRequestType, string> (typFromDU, typToDU)

    /// Conversion between a string and a RequestSort DU value
    type RequestSortConverter () =
        inherit ValueConverter<RequestSort, string> (sortFromDU, sortToDU)


/// Statistics for churches
[<NoComparison; NoEquality>]
type ChurchStats =
    {   /// The number of small groups in the church
        smallGroups    : int
        
        /// The number of prayer requests in the church
        prayerRequests : int
        
        /// The number of users who can access small groups in the church
        users          : int
    }

/// PK type for the Church entity
type ChurchId = Guid

/// PK type for the Member entity
type MemberId = Guid

/// PK type for the PrayerRequest entity
type PrayerRequestId = Guid

/// PK type for the SmallGroup entity
type SmallGroupId = Guid

/// PK type for the TimeZone entity
type TimeZoneId = string

/// PK type for the User entity
type UserId = Guid

/// PK for User/SmallGroup cross-reference table
type UserSmallGroupKey =
  {   /// The ID of the user to whom access is granted
      userId       : UserId
      
      /// The ID of the small group to which the entry grants access
      smallGroupId : SmallGroupId
   }

(*-- ENTITIES --*)

/// This represents a church
type [<CLIMutable; NoComparison; NoEquality>] Church =
    {   /// The Id of this church
        churchId         : ChurchId
        
        /// The name of the church
        name             : string
        
        /// The city where the church is
        city             : string
        
        /// The state where the church is
        st               : string
        
        /// Does this church have an active interface with Virtual Prayer Room?
        hasInterface     : bool
        
        /// The address for the interface
        interfaceAddress : string option
        
        /// Small groups for this church
        smallGroups      : ICollection<SmallGroup>
    }
with
    /// An empty church
    // aww... how sad :(
    static member empty =
        { churchId         = Guid.Empty
          name             = ""
          city             = ""
          st               = ""
          hasInterface     = false
          interfaceAddress = None
          smallGroups      = List<SmallGroup> ()
        }
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<Church> (fun m ->
            m.ToTable "Church" |> ignore
            m.Property(fun e -> e.churchId).HasColumnName "ChurchId" |> ignore
            m.Property(fun e -> e.name).HasColumnName("Name").IsRequired () |> ignore
            m.Property(fun e -> e.city).HasColumnName("City").IsRequired () |> ignore
            m.Property(fun e -> e.st).HasColumnName("ST").IsRequired().HasMaxLength 2 |> ignore
            m.Property(fun e -> e.hasInterface).HasColumnName "HasVirtualPrayerRoomInterface" |> ignore
            m.Property(fun e -> e.interfaceAddress).HasColumnName "InterfaceAddress" |> ignore)
        |> ignore
        mb.Model.FindEntityType(typeof<Church>).FindProperty("interfaceAddress")
            .SetValueConverter(OptionConverter<string> ())


/// Preferences for the form and format of the prayer request list
and [<CLIMutable; NoComparison; NoEquality>] ListPreferences =
    {   /// The Id of the small group to which these preferences belong
        smallGroupId        : SmallGroupId
        
        /// The days after which regular requests expire
        daysToExpire        : int
        
        /// The number of days a new or updated request is considered new
        daysToKeepNew       : int
        
        /// The number of weeks after which long-term requests are flagged for follow-up
        longTermUpdateWeeks : int
        
        /// The name from which e-mails are sent
        emailFromName       : string
        
        /// The e-mail address from which e-mails are sent
        emailFromAddress    : string
        
        /// The fonts to use in generating the list of prayer requests
        listFonts           : string
        
        /// The color for the prayer request list headings
        headingColor        : string
        
        /// The color for the lines offsetting the prayer request list headings
        lineColor           : string
        
        /// The font size for the headings on the prayer request list
        headingFontSize     : int
        
        /// The font size for the text on the prayer request list
        textFontSize        : int
        
        /// The order in which the prayer requests are sorted
        requestSort         : RequestSort
        
        /// The password used for "small group login" (view-only request list)
        groupPassword       : string
        
        /// The default e-mail type for this class
        defaultEmailType    : EmailFormat
        
        /// Whether this class makes its request list public
        isPublic            : bool
        
        /// The time zone which this class uses (use tzdata names)
        timeZoneId          : TimeZoneId
        
        /// The time zone information
        timeZone            : TimeZone
        
        /// The number of requests displayed per page
        pageSize            : int
        
        /// How the as-of date should be automatically displayed
        asOfDateDisplay     : AsOfDateDisplay
    }
with
    
    /// A set of preferences with their default values
    static member empty =
        { smallGroupId        = Guid.Empty
          daysToExpire        = 14
          daysToKeepNew       = 7
          longTermUpdateWeeks = 4
          emailFromName       = "PrayerTracker"
          emailFromAddress    = "prayer@djs-consulting.com"
          listFonts           = "Century Gothic,Tahoma,Luxi Sans,sans-serif"
          headingColor        = "maroon"
          lineColor           = "navy"
          headingFontSize     = 16
          textFontSize        = 12
          requestSort         = SortByDate
          groupPassword       = ""
          defaultEmailType    = HtmlFormat
          isPublic            = false
          timeZoneId          = "America/Denver"
          timeZone            = TimeZone.empty
          pageSize            = 100
          asOfDateDisplay     = NoDisplay
        }
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<ListPreferences> (fun m ->
            m.ToTable "ListPreference" |> ignore
            m.HasKey (fun e -> e.smallGroupId :> obj) |> ignore
            m.Property(fun e -> e.smallGroupId).HasColumnName "SmallGroupId" |> ignore
            m.Property(fun e -> e.daysToKeepNew)
                .HasColumnName("DaysToKeepNew")
                .IsRequired()
                .HasDefaultValue 7
            |> ignore
            m.Property(fun e -> e.daysToExpire)
                .HasColumnName("DaysToExpire")
                .IsRequired()
                .HasDefaultValue 14
            |> ignore
            m.Property(fun e -> e.longTermUpdateWeeks)
                .HasColumnName("LongTermUpdateWeeks")
                .IsRequired()
                .HasDefaultValue 4
            |> ignore
            m.Property(fun e -> e.emailFromName)
                .HasColumnName("EmailFromName")
                .IsRequired()
                .HasDefaultValue "PrayerTracker"
            |> ignore
            m.Property(fun e -> e.emailFromAddress)
                .HasColumnName("EmailFromAddress")
                .IsRequired()
                .HasDefaultValue "prayer@djs-consulting.com"
              |> ignore
            m.Property(fun e -> e.listFonts)
                .HasColumnName("ListFonts")
                .IsRequired()
                .HasDefaultValue "Century Gothic,Tahoma,Luxi Sans,sans-serif"
            |> ignore
            m.Property(fun e -> e.headingColor)
                .HasColumnName("HeadingColor")
                .IsRequired()
                .HasDefaultValue "maroon"
            |> ignore
            m.Property(fun e -> e.lineColor)
                .HasColumnName("LineColor")
                .IsRequired()
                .HasDefaultValue "navy"
            |> ignore
            m.Property(fun e -> e.headingFontSize)
                .HasColumnName("HeadingFontSize")
                .IsRequired()
                .HasDefaultValue 16
            |> ignore
            m.Property(fun e -> e.textFontSize)
                .HasColumnName("TextFontSize")
                .IsRequired()
                .HasDefaultValue 12
            |> ignore
            m.Property(fun e -> e.requestSort)
                .HasColumnName("RequestSort")
                .IsRequired()
                .HasMaxLength(1)
                .HasDefaultValue SortByDate
            |> ignore
            m.Property(fun e -> e.groupPassword)
                .HasColumnName("GroupPassword")
                .IsRequired()
                .HasDefaultValue ""
            |> ignore
            m.Property(fun e -> e.defaultEmailType)
                .HasColumnName("DefaultEmailType")
                .IsRequired()
                .HasDefaultValue HtmlFormat
            |> ignore
            m.Property(fun e -> e.isPublic)
                .HasColumnName("IsPublic")
                .IsRequired()
                .HasDefaultValue false
            |> ignore
            m.Property(fun e -> e.timeZoneId)
                .HasColumnName("TimeZoneId")
                .IsRequired()
                .HasDefaultValue "America/Denver"
            |> ignore
            m.Property(fun e -> e.pageSize)
                .HasColumnName("PageSize")
                .IsRequired()
                .HasDefaultValue 100
            |> ignore
            m.Property(fun e -> e.asOfDateDisplay)
                .HasColumnName("AsOfDateDisplay")
                .IsRequired()
                .HasMaxLength(1)
                .HasDefaultValue NoDisplay
            |> ignore)
        |> ignore
        mb.Model.FindEntityType(typeof<ListPreferences>).FindProperty("requestSort")
            .SetValueConverter(Converters.RequestSortConverter ())
        mb.Model.FindEntityType(typeof<ListPreferences>).FindProperty("defaultEmailType")
            .SetValueConverter(Converters.EmailFormatConverter ())
        mb.Model.FindEntityType(typeof<ListPreferences>).FindProperty("asOfDateDisplay")
            .SetValueConverter(Converters.AsOfDateDisplayConverter ())


/// A member of a small group
and [<CLIMutable; NoComparison; NoEquality>] Member =
    {   /// The Id of the member
        memberId     : MemberId
        
        /// The Id of the small group to which this member belongs
        smallGroupId : SmallGroupId
        
        /// The name of the member
        memberName   : string
        
        /// The e-mail address for the member
        email        : string
        
        /// The type of e-mail preferred by this member (see <see cref="EmailTypes"/> constants)
        format       : string option // TODO - do I need a custom formatter for this?
        
        /// The small group to which this member belongs
        smallGroup   : SmallGroup
    }
with
    
    /// An empty member
    static member empty =
        { memberId     = Guid.Empty
          smallGroupId = Guid.Empty
          memberName   = ""
          email        = ""
          format       = None
          smallGroup   = SmallGroup.empty
        }
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<Member> (fun m ->
            m.ToTable "Member" |> ignore
            m.Property(fun e -> e.memberId).HasColumnName "MemberId" |> ignore
            m.Property(fun e -> e.smallGroupId).HasColumnName "SmallGroupId" |> ignore
            m.Property(fun e -> e.memberName).HasColumnName("MemberName").IsRequired() |> ignore
            m.Property(fun e -> e.email).HasColumnName("Email").IsRequired() |> ignore
            m.Property(fun e -> e.format).HasColumnName "Format" |> ignore)
        |> ignore
        mb.Model.FindEntityType(typeof<Member>).FindProperty("format").SetValueConverter(OptionConverter<string> ())


/// This represents a single prayer request
and [<CLIMutable; NoComparison; NoEquality>] PrayerRequest =
    {   /// The Id of this request
        prayerRequestId : PrayerRequestId
        
        /// The type of the request
        requestType     : PrayerRequestType
        
        /// The user who entered the request
        userId          : UserId
        
        /// The small group to which this request belongs
        smallGroupId    : SmallGroupId
        
        /// The date/time on which this request was entered
        enteredDate     : DateTime
        
        /// The date/time this request was last updated
        updatedDate     : DateTime
        
        /// The name of the requestor or subject, or title of announcement
        requestor       : string option
        
        /// The text of the request
        text            : string
        
        /// Whether the chaplain should be notified for this request
        notifyChaplain  : bool
        
        /// The user who entered this request
        user            : User
        
        /// The small group to which this request belongs
        smallGroup      : SmallGroup
        
        /// Is this request expired?
        expiration      : Expiration
    }
with
    
    /// An empty request
    static member empty =
        { prayerRequestId = Guid.Empty
          requestType     = CurrentRequest
          userId          = Guid.Empty
          smallGroupId    = Guid.Empty
          enteredDate     = DateTime.MinValue
          updatedDate     = DateTime.MinValue
          requestor       = None
          text            = "" 
          notifyChaplain  = false
          user            = User.empty
          smallGroup      = SmallGroup.empty
          expiration      = Automatic
        }
    
    /// Is this request expired?
    member this.isExpired (curr : DateTime) expDays =
        match this.expiration with
        | Forced -> true
        | Manual -> false 
        | Automatic ->
            match this.requestType with
            | LongTermRequest
            | Expecting -> false
            | _ -> curr.AddDays(-(float expDays)).Date > this.updatedDate.Date // Automatic expiration

    /// Is an update required for this long-term request?
    member this.updateRequired curr expDays updWeeks =
        match this.isExpired curr expDays with
        | true -> false
        | false -> curr.AddDays(-(float (updWeeks * 7))).Date > this.updatedDate.Date

    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<PrayerRequest> (fun m ->
            m.ToTable "PrayerRequest" |> ignore
            m.Property(fun e -> e.prayerRequestId).HasColumnName "PrayerRequestId" |> ignore
            m.Property(fun e -> e.requestType).HasColumnName("RequestType").IsRequired() |> ignore
            m.Property(fun e -> e.userId).HasColumnName "UserId" |> ignore
            m.Property(fun e -> e.smallGroupId).HasColumnName "SmallGroupId" |> ignore
            m.Property(fun e -> e.enteredDate).HasColumnName "EnteredDate" |> ignore
            m.Property(fun e -> e.updatedDate).HasColumnName "UpdatedDate" |> ignore
            m.Property(fun e -> e.requestor).HasColumnName "Requestor" |> ignore
            m.Property(fun e -> e.text).HasColumnName("Text").IsRequired() |> ignore
            m.Property(fun e -> e.notifyChaplain).HasColumnName "NotifyChaplain" |> ignore
            m.Property(fun e -> e.expiration).HasColumnName "Expiration" |> ignore)
        |> ignore
        mb.Model.FindEntityType(typeof<PrayerRequest>).FindProperty("requestType")
            .SetValueConverter(Converters.PrayerRequestTypeConverter ())
        mb.Model.FindEntityType(typeof<PrayerRequest>).FindProperty("requestor")
            .SetValueConverter(OptionConverter<string> ())
        mb.Model.FindEntityType(typeof<PrayerRequest>).FindProperty("expiration")
            .SetValueConverter(Converters.ExpirationConverter ())


/// This represents a small group (Sunday School class, Bible study group, etc.)
and [<CLIMutable; NoComparison; NoEquality>] SmallGroup =
    {   /// The Id of this small group
        smallGroupId   : SmallGroupId
        
        /// The church to which this group belongs
        churchId       : ChurchId
        
        /// The name of the group
        name           : string
        
        /// The church to which this small group belongs
        church         : Church
        
        /// The preferences for the request list
        preferences    : ListPreferences
        
        /// The members of the group
        members        : ICollection<Member>
        
        /// Prayer requests for this small group
        prayerRequests : ICollection<PrayerRequest>
        
        /// The users authorized to manage this group
        users          : ICollection<UserSmallGroup>
    }
with
    
    /// An empty small group
    static member empty =
        { smallGroupId   = Guid.Empty
          churchId       = Guid.Empty
          name           = "" 
          church         = Church.empty
          preferences    = ListPreferences.empty
          members        = List<Member> ()
          prayerRequests = List<PrayerRequest> ()
          users          = List<UserSmallGroup> ()
        }

    /// Get the local date for this group
    member this.localTimeNow (clock : IClock) =
        match clock with null -> nullArg "clock" | _ -> ()
        let tz =
            if DateTimeZoneProviders.Tzdb.Ids.Contains this.preferences.timeZoneId then
                DateTimeZoneProviders.Tzdb[this.preferences.timeZoneId]
            else DateTimeZone.Utc
        clock.GetCurrentInstant().InZone(tz).ToDateTimeUnspecified ()

    /// Get the local date for this group
    member this.localDateNow clock =
        (this.localTimeNow clock).Date
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<SmallGroup> (fun m ->
            m.ToTable "SmallGroup" |> ignore
            m.Property(fun e -> e.smallGroupId).HasColumnName "SmallGroupId" |> ignore
            m.Property(fun e -> e.churchId).HasColumnName "ChurchId" |> ignore
            m.Property(fun e -> e.name).HasColumnName("Name").IsRequired() |> ignore
            m.HasOne(fun e -> e.preferences) |> ignore)
        |> ignore


/// This represents a time zone in which a class may reside
and [<CLIMutable; NoComparison; NoEquality>] TimeZone =
    {   /// The Id for this time zone (uses tzdata names)
        timeZoneId  : TimeZoneId
        
        /// The description of this time zone
        description : string
        
        /// The order in which this timezone should be displayed
        sortOrder   : int
        
        /// Whether this timezone is active
        isActive    : bool
    }
with
    
    /// An empty time zone
    static member empty =
        { timeZoneId  = ""
          description = ""
          sortOrder   = 0
          isActive    = false
        }
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<TimeZone> ( fun m ->
            m.ToTable "TimeZone" |> ignore
            m.Property(fun e -> e.timeZoneId).HasColumnName "TimeZoneId" |> ignore
            m.Property(fun e -> e.description).HasColumnName("Description").IsRequired() |> ignore
            m.Property(fun e -> e.sortOrder).HasColumnName "SortOrder" |> ignore
            m.Property(fun e -> e.isActive).HasColumnName "IsActive" |> ignore)
        |> ignore


/// This represents a user of PrayerTracker
and [<CLIMutable; NoComparison; NoEquality>] User =
    {   /// The Id of this user
        userId       : UserId
        
        /// The first name of this user
        firstName    : string
        
        /// The last name of this user
        lastName     : string
        
        /// The e-mail address of the user
        emailAddress : string
        
        /// Whether this user is a PrayerTracker system administrator
        isAdmin      : bool
        
        /// The user's hashed password
        passwordHash : string
        
        /// The salt for the user's hashed password
        salt         : Guid option
        
        /// The small groups which this user is authorized
        smallGroups  : ICollection<UserSmallGroup>
    }
with
    
    /// An empty user
    static member empty =
        { userId       = Guid.Empty
          firstName    = ""
          lastName     = ""
          emailAddress = ""
          isAdmin      = false
          passwordHash = ""
          salt         = None
          smallGroups  = List<UserSmallGroup> ()
        }
    
    /// The full name of the user
    member this.fullName =
        $"{this.firstName} {this.lastName}"

    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<User> (fun m ->
            m.ToTable "User" |> ignore
            m.Ignore(fun e -> e.fullName :> obj) |> ignore
            m.Property(fun e -> e.userId).HasColumnName "UserId" |> ignore
            m.Property(fun e -> e.firstName).HasColumnName("FirstName").IsRequired() |> ignore
            m.Property(fun e -> e.lastName).HasColumnName("LastName").IsRequired() |> ignore
            m.Property(fun e -> e.emailAddress).HasColumnName("EmailAddress").IsRequired() |> ignore
            m.Property(fun e -> e.isAdmin).HasColumnName "IsSystemAdmin" |> ignore
            m.Property(fun e -> e.passwordHash).HasColumnName("PasswordHash").IsRequired() |> ignore
            m.Property(fun e -> e.salt).HasColumnName "Salt" |> ignore)
        |> ignore
        mb.Model.FindEntityType(typeof<User>).FindProperty("salt")
            .SetValueConverter(OptionConverter<Guid> ())


/// Cross-reference between user and small group
and [<CLIMutable; NoComparison; NoEquality>] UserSmallGroup =
    {   /// The Id of the user who has access to the small group
        userId       : UserId
        
        /// The Id of the small group to which the user has access
        smallGroupId : SmallGroupId
        
        /// The user who has access to the small group
        user         : User
        
        /// The small group to which the user has access
        smallGroup   : SmallGroup
    }
with
    
    /// An empty user/small group xref
    static member empty =
        { userId       = Guid.Empty
          smallGroupId = Guid.Empty
          user         = User.empty
          smallGroup   = SmallGroup.empty
        }
    
    /// Configure EF for this entity
    static member internal configureEF (mb : ModelBuilder) =
        mb.Entity<UserSmallGroup> (fun m ->
            m.ToTable "User_SmallGroup" |> ignore
            m.HasKey(fun e -> { userId = e.userId; smallGroupId = e.smallGroupId } :> obj) |> ignore
            m.Property(fun e -> e.userId).HasColumnName "UserId" |> ignore
            m.Property(fun e -> e.smallGroupId).HasColumnName "SmallGroupId" |> ignore
            m.HasOne(fun e -> e.user)
                .WithMany(fun e -> e.smallGroups :> IEnumerable<UserSmallGroup>)
                .HasForeignKey(fun e -> e.userId :> obj)
            |> ignore
            m.HasOne(fun e -> e.smallGroup)
                .WithMany(fun e -> e.users :> IEnumerable<UserSmallGroup>)
                .HasForeignKey(fun e -> e.smallGroupId :> obj)
            |> ignore)
        |> ignore