module Colour = struct
  type t = { red : int; green : int; blue : int } [@@fieldglass generate]
end

module Legacy = struct
  type t = { value : string } [@@lens generate]
end

let () =
  let colour = Colour.{ red = 3; green = 4; blue = 5 } in
  assert (Colour.red colour = 3);
  assert (Colour.green colour = 4);
  assert (Legacy.value Legacy.{ value = "grey" } = "grey")

module Box = struct
  type 'a t = { contents : 'a } [@@fieldglass generate]
end

module Mutable = struct
  type t = { mutable count : int; label : string } [@@fieldglass generate]
end

let () =
  let original = Colour.{ red = 3; green = 4; blue = 5 } in
  assert (Colour.set_red 8 original = Colour.{ red = 8; green = 4; blue = 5 });
  assert (Colour.red original = 3);
  assert (Box.set_contents "grey" Box.{ contents = 9 } = Box.{ contents = "grey" });
  let original = Mutable.{ count = 1; label = "grey" } in
  let changed = Mutable.set_count 2 original in
  assert (original.Mutable.count = 1 && changed.Mutable.count = 2)

let () =
  let calls = ref 0 in
  let original = Colour.{ red = 3; green = 4; blue = 5 } in
  let changed = Colour.update_green ~f:(fun n -> incr calls; n + 1) original in
  assert (Colour.green changed = 5 && !calls = 1);
  assert (Box.update_contents ~f:string_of_int Box.{ contents = 9 } = Box.{ contents = "9" });
  (try ignore (Colour.update_red ~f:(fun _ -> failwith "callback") original); assert false
   with Failure message -> assert (message = "callback"));
  assert (Colour.red original = 3)

module Swatch = struct
  type t = { colour : Colour.t; label : string } [@@fieldglass generate]
end

let () =
  let open Fieldglass in
  let original = Swatch.{ colour = Colour.{ red = 3; green = 4; blue = 5 }; label = "grey" } in
  let focus = compose Swatch._colour Colour._red in
  assert (view focus original = 3);
  let changed = set focus 8 original in
  assert (view focus changed = 8 && Swatch.label changed = "grey");
  assert (set focus (view focus original) original = original);
  assert (set Box._contents "grey" Box.{ contents = 9 } = Box.{ contents = "grey" })

module Prefixed = struct
  type t = { paint_colour_red : int; paint_colour_green : int } [@@fieldglass generate]
end

module Unprefixed = struct
  type t = { yes : bool; yellow : bool } [@@fieldglass generate]
end

module Single = struct
  type t = { paint_red : int } [@@fieldglass generate]
end

let () =
  assert (Prefixed.red Prefixed.{ paint_colour_red = 3; paint_colour_green = 4 } = 3);
  assert (Unprefixed.yes Unprefixed.{ yes = true; yellow = false });
  assert (Single.paint_red Single.{ paint_red = 3 } = 3)

module Named = struct
  type t = { item_colour : string; item_size : int }
    [@@fieldglass generate ~field_prefix:swatch]
end

module Typed = struct
  type swatch = { item_colour : string; item_size : int }
    [@@fieldglass generate ~field_prefix_from_type]
end

let () =
  assert (Named.swatch_colour Named.{ item_colour = "grey"; item_size = 3 } = "grey");
  assert (Typed.swatch_size Typed.{ item_colour = "grey"; item_size = 3 } = 3)

module Verbs = struct
  type t = { colour : string }
    [@@fieldglass generate ~get_prefix:read ~set_prefix:replace ~update_prefix:"revise"]
end

let () =
  let original = Verbs.{ colour = "grey" } in
  assert (Verbs.read_colour original = "grey");
  assert (Verbs.read_colour (Verbs.replace_colour "blue" original) = "blue");
  assert (Verbs.read_colour (Verbs.revise_colour ~f:(fun s -> s ^ "s") original) = "greys");
  assert (Fieldglass.view Verbs._colour original = "grey")

module Ordered = struct
  type t = { count : int }
    [@@fieldglass generate ~self_arg_first ~func_named_arg:change]
end

module Positional = struct
  type t = { count : int }
    [@@fieldglass generate ~self_arg_first ~func_no_named_arg]
end

module Last = struct
  type t = { count : int } [@@fieldglass generate ~func_no_named_arg]
end

let () =
  assert (Ordered.set_count Ordered.{ count = 1 } 2 = Ordered.{ count = 2 });
  assert (Ordered.update_count Ordered.{ count = 1 } ~change:succ = Ordered.{ count = 2 });
  assert (Fieldglass.set Ordered._count 2 Ordered.{ count = 1 } = Ordered.{ count = 2 });
  assert (Positional.update_count Positional.{ count = 1 } succ = Positional.{ count = 2 });
  assert (Last.update_count succ Last.{ count = 1 } = Last.{ count = 2 })

module Pairs = struct
  type t = { colour : string } [@@fieldglass generate ~just_lens]
end

module Silent = struct
  type t = { colour : string } [@@fieldglass generate ~just_lens ~no_lens]
end

module Functions = struct
  type t = { colour : string } [@@fieldglass generate ~no_lens ~no_get:false]
end

let () =
  assert (Fieldglass.view Pairs._colour Pairs.{ colour = "grey" } = "grey");
  assert (Silent.{ colour = "grey" }.colour = "grey");
  assert (Functions.colour Functions.{ colour = "grey" } = "grey")