module Make (Storage : Management.Physical.S) = struct
  module Ops = Manipulation.Make(Storage)

  type error =
    | ParseError        of string
    | ManipulationError of Manipulation.error
    | ConversionError   of string

  let sexp_of_error e =
    let open Sexplib.Sexp in
    match e with
    | ParseError s        -> List [Atom "parse-error";      Atom s]
    | ManipulationError e -> Manipulation.sexp_of_error e
    | ConversionError s   -> List [Atom "conversion-error"; Atom s]

  let wrap_manip = Result.map_error (fun e -> ManipulationError e)

  let convert_binding_expr : Ast.binding_expr -> Constraint.binding_expr = function
    | Ast.Var name -> Constraint.Var name
    | Ast.Const value -> Constraint.Const (Drl.Ast.value_to_abstract value)

  let convert_binding (pairs : (string * Ast.binding_expr) list) : Constraint.binding =
    List.fold_left
      (fun acc (key, expr) ->
        Constraint.BindingMap.add key (convert_binding_expr expr) acc)
      Constraint.BindingMap.empty
      pairs

  let rec convert_body : Ast.constraint_body -> Constraint.t = function
    | Ast.MemberOf { target; binding } ->
      Constraint.MemberOf { target; binding = convert_binding binding }
    | Ast.Not { body; universe } ->
      Constraint.Not { body = convert_body body; universe }
    | Ast.And bodies ->
      Constraint.And (List.map convert_body bodies)
    | Ast.Or bodies ->
      Constraint.Or (List.map convert_body bodies)
    | Ast.Exists { variable; quantifier; body } ->
      Constraint.Exists { variable; quantifier; body = convert_body body }
    | Ast.Forall { variable; quantifier; body } ->
      Constraint.Forall { variable; quantifier; body = convert_body body }

  let execute
      (storage : Storage.t)
      (db : Management.Database.t)
      (stmt : Ast.statement)
    : (Management.Database.t * string, error) result =
    match stmt with
    | Ast.RegisterConstraint { constraint_name; relation_name; body } ->
      let runtime_body = convert_body body in
      (match Ops.register_constraint storage db
               ~constraint_name ~relation_name ~body:runtime_body
             |> wrap_manip with
       | Ok new_db -> Ok (new_db, "Constraint registered: " ^ constraint_name)
       | Error e   -> Error e)
end

module Memory = Make(Management.Physical.Memory)