bright

-module(bright).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([init/2, update/2, compute/2, schedule/2, unwrap/1, state/1, computed/1, step/2, start/2, lazy_compute/3, lazy_schedule/3]).
-export_type([bright/2]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-opaque bright(MUA, MUB) :: {bright,
        MUA,
        MUB,
        list(gleam@dynamic:dynamic_()),
        list(gleam@dynamic:dynamic_())}.

-file("src/bright.gleam", 21).
?DOC(
    " Creates the initial `Bright`. `state` & `computed` should be initialised with\n"
    " their correct empty initial state.\n"
).
-spec init(MUC, MUD) -> bright(MUC, MUD).
init(State, Computed) ->
    {bright, State, Computed, [], []}.

-file("src/bright.gleam", 60).
?DOC(
    " Update state & effects during update cycle. Use it a way to update your state\n"
    " stored in `Bright`, and chain them with other `bright` calls.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   use model <- bright.start(model)\n"
    "   // Run an update, and returns #(Bright(state, computed), Effect(msg)).\n"
    "   bright.update(model, update_state(_, msg))\n"
    " }\n"
    " ```\n"
).
-spec update(
    {bright(MUT, MUU), lustre@effect:effect(MUX)},
    fun((MUT) -> {MUT, lustre@effect:effect(MUX)})
) -> {bright(MUT, MUU), lustre@effect:effect(MUX)}.
update(Bright, Update_) ->
    {Bright@1, Effects} = Bright,
    {State, Effect} = Update_(erlang:element(2, Bright@1)),
    {begin
            _record = Bright@1,
            {bright,
                State,
                erlang:element(3, _record),
                erlang:element(4, _record),
                erlang:element(5, _record)}
        end,
        lustre@effect:batch([Effects, Effect])}.

-file("src/bright.gleam", 83).
?DOC(
    " Derives data from the `data` state, and potentially the current `computed`\n"
    " state. `compute` will run **at every render**, so be careful with computations\n"
    " as they can block paint or actors.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   use model <- bright.start(model)\n"
    "   model\n"
    "   |> bright.update(update_state(_, msg))\n"
    "   |> bright.compute(fn (d, c) { Computed(..c, field1: computation1(d)) })\n"
    "   |> bright.compute(fn (d, c) { Computed(..c, field2: computation2(d)) })\n"
    "   |> bright.compute(fn (d, c) { Computed(..c, field3: computation3(d)) })\n"
    " }\n"
    " ```\n"
).
-spec compute(
    {bright(MVD, MVE), lustre@effect:effect(MVH)},
    fun((MVD, MVE) -> MVE)
) -> {bright(MVD, MVE), lustre@effect:effect(MVH)}.
compute(Bright, Compute_) ->
    gleam@pair:map_first(
        Bright,
        fun(Bright@1) ->
            _pipe = Compute_(
                erlang:element(2, Bright@1),
                erlang:element(3, Bright@1)
            ),
            (fun(Computed) -> _record = Bright@1,
                {bright,
                    erlang:element(2, _record),
                    Computed,
                    erlang:element(4, _record),
                    erlang:element(5, _record)} end)(_pipe)
        end
    ).

-file("src/bright.gleam", 109).
?DOC(
    " Plugs in existing `state` and `computed` state, to issue some side-effects,\n"
    " when your application needs to run side-effects depending on the current state.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   use model <- bright.start(model)\n"
    "   model\n"
    "   |> bright.update(update_state(_, msg))\n"
    "   |> bright.schedule(model, fn (state, computed) {\n"
    "     use dispatch <- effect.from\n"
    "     case state.field == 10 {\n"
    "       True -> dispatch(my_msg)\n"
    "       False -> Nil\n"
    "     }\n"
    "   })\n"
    " }\n"
    " ```\n"
).
-spec schedule(
    {bright(MVM, MVN), lustre@effect:effect(MVQ)},
    fun((MVM, MVN) -> lustre@effect:effect(MVQ))
) -> {bright(MVM, MVN), lustre@effect:effect(MVQ)}.
schedule(Bright, Schedule_) ->
    {Bright@1, Effects} = Bright,
    Effect = Schedule_(erlang:element(2, Bright@1), erlang:element(3, Bright@1)),
    {Bright@1, lustre@effect:batch([Effects, Effect])}.

-file("src/bright.gleam", 196).
?DOC(
    " Extracts `state` & `computed` states from `Bright`.\n"
    "\n"
    " ```gleam\n"
    " pub fn view(model: Bright(state, computed)) {\n"
    "   let #(state, computed) = bright.unwrap(model)\n"
    "   html.div([], [\n"
    "     // Use state or computed here.\n"
    "   ])\n"
    " }\n"
    " ```\n"
).
-spec unwrap(bright(MWR, MWS)) -> {MWR, MWS}.
unwrap(Bright) ->
    {erlang:element(2, Bright), erlang:element(3, Bright)}.

-file("src/bright.gleam", 210).
?DOC(
    " Extracts `state` state from `Bright`.\n"
    "\n"
    " ```gleam\n"
    " pub fn view(model: Bright(state, computed)) {\n"
    "   let state = bright.state(model)\n"
    "   html.div([], [\n"
    "     // Use state here.\n"
    "   ])\n"
    " }\n"
    " ```\n"
).
-spec state(bright(MWV, any())) -> MWV.
state(Bright) ->
    erlang:element(2, Bright).

-file("src/bright.gleam", 224).
?DOC(
    " Extracts `computed` state from `Bright`.\n"
    "\n"
    " ```gleam\n"
    " pub fn view(model: Bright(state, computed)) {\n"
    "   let computed = bright.computed(model)\n"
    "   html.div([], [\n"
    "     // Use computed here.\n"
    "   ])\n"
    " }\n"
    " ```\n"
).
-spec computed(bright(any(), MXA)) -> MXA.
computed(Bright) ->
    erlang:element(3, Bright).

-file("src/bright.gleam", 246).
?DOC(
    " Allows to run multiple `update` on multiple `Bright` in the same update cycle.\n"
    " Every call to step with compute a new `Bright`, and will let you chain the\n"
    " steps.\n"
    "\n"
    " ```gleam\n"
    " pub type Model {\n"
    "   Model(\n"
    "     fst_bright: Bright(state, computed),\n"
    "     snd_bright: Bright(state, computed),\n"
    "   )\n"
    " }\n"
    "\n"
    " fn update(model: Model, msg: Msg) {\n"
    "   use fst_bright <- bright.step(update_fst(model.fst_bright, msg))\n"
    "   use snd_bright <- bright.step(update_snd(model.snd_bright, msg))\n"
    "   #(Model(fst_bright:, snd_bright:), effect.none())\n"
    " }\n"
    " ```\n"
).
-spec step(
    {bright(MXD, MXE), lustre@effect:effect(MXH)},
    fun((bright(MXD, MXE)) -> {MXL, lustre@effect:effect(MXH)})
) -> {MXL, lustre@effect:effect(MXH)}.
step(Bright, Next) ->
    {Bright@1, Effs} = Bright,
    {Model, Effs_} = Next(Bright@1),
    {Model, lustre@effect:batch([Effs, Effs_])}.

-file("src/bright.gleam", 281).
-spec panic_if_different_computations_count(list(any()), list(any())) -> nil.
panic_if_different_computations_count(Old_computations, Computations) ->
    Count = erlang:length(Old_computations),
    gleam@bool:guard(
        Count =:= 0,
        nil,
        fun() ->
            Is_same_count = Count =:= erlang:length(Computations),
            gleam@bool:guard(
                Is_same_count,
                nil,
                fun() -> erlang:error(#{gleam_error => panic,
                            message => <<"Memoized computed should be consistent over time, otherwise memo can not work."/utf8>>,
                            module => <<"bright"/utf8>>,
                            function => <<"panic_if_different_computations_count"/utf8>>,
                            line => 289}) end
            )
        end
    ).

-file("src/bright.gleam", 38).
?DOC(
    " Start the Bright update cycle. Use it as a way to trigger the start of `Bright`\n"
    " computations, and chain them with other `bright` calls. `start` handles all\n"
    " of the hard work, of turning a `Bright(state, computed)` into a\n"
    " `#(Bright(state, computed), Effect(msg))`, and will take care that your\n"
    " `Bright(state, computed)` is always consistent over multiple update cycles.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   // Starts the update cycle, and returns #(Bright(state, computed), Effect(msg)).\n"
    "   use model <- bright.start(model)\n"
    "   bright.update(model, update_state(_, msg))\n"
    " }\n"
    " ```\n"
).
-spec start(
    bright(MUF, MUG),
    fun(({bright(MUF, MUG), lustre@effect:effect(MUL)}) -> {bright(MUF, MUG),
        lustre@effect:effect(MUL)})
) -> {bright(MUF, MUG), lustre@effect:effect(MUL)}.
start(Bright, Next) ->
    Old_computations = erlang:element(5, Bright),
    gleam@pair:map_first(
        Next({Bright, lustre@effect:none()}),
        fun(New_data) ->
            panic_if_different_computations_count(
                Old_computations,
                erlang:element(4, New_data)
            ),
            Past_selections = lists:reverse(erlang:element(4, New_data)),
            _record = New_data,
            {bright,
                erlang:element(2, _record),
                erlang:element(3, _record),
                [],
                Past_selections}
        end
    ).

-file("src/bright.gleam", 296).
?DOC(
    " Optimization on JS, to ensure that two data sharing the referential equality\n"
    " will shortcut the comparison. Useful when performance are a thing in client\n"
    " browser. Otherwise, rely on Erlang equality.\n"
).
-spec are_dependencies_equal(any(), any()) -> boolean().
are_dependencies_equal(A, B) ->
    gleam_stdlib:identity(A) =:= gleam_stdlib:identity(B).

-file("src/bright.gleam", 255).
-spec lazy_wrap(
    {bright(MXO, MXP), lustre@effect:effect(MXS)},
    fun((MXO) -> MXU),
    fun(({bright(MXO, MXP), lustre@effect:effect(MXS)}, fun((MXO, MXP) -> MXY)) -> {bright(MXO, MXP),
        lustre@effect:effect(MXS)}),
    fun((MXO, MXP, MXU) -> MXY)
) -> {bright(MXO, MXP), lustre@effect:effect(MXS)}.
lazy_wrap(Bright, Selector, Setter, Compute_) ->
    Selected_data = Selector(erlang:element(2, (erlang:element(1, Bright)))),
    Selections = [gleam_stdlib:identity(Selected_data) |
        erlang:element(4, (erlang:element(1, Bright)))],
    Compute_@1 = fun(Data, Computed) ->
        Compute_(Data, Computed, Selected_data)
    end,
    Bright@1 = {begin
            _record = erlang:element(1, Bright),
            {bright,
                erlang:element(2, _record),
                erlang:element(3, _record),
                Selections,
                erlang:element(5, _record)}
        end,
        erlang:element(2, Bright)},
    case erlang:element(5, (erlang:element(1, Bright@1))) of
        [] ->
            Setter(Bright@1, Compute_@1);

        [Value | Past_selections] ->
            _pipe = {begin
                    _record@1 = erlang:element(1, Bright@1),
                    {bright,
                        erlang:element(2, _record@1),
                        erlang:element(3, _record@1),
                        erlang:element(4, _record@1),
                        Past_selections}
                end,
                erlang:element(2, Bright@1)},
            case are_dependencies_equal(Value, Selected_data) of
                true ->
                    fun gleam@function:identity/1;

                false ->
                    fun(_capture) -> Setter(_capture, Compute_@1) end
            end(_pipe)
    end.

-file("src/bright.gleam", 142).
?DOC(
    " Derives data like [`compute`](#compute) lazily. `lazy_compute` accepts a\n"
    " selector as second argument. Each time the selector returns a different data\n"
    " than previous run, the computation will run. Otherwise, nothing happens.\n"
    " The computation function will receive `state`, `computed` and the selected\n"
    " data (i.e. the result from your selector function), in case accessing the\n"
    " selected data is needed.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   use model <- bright.start(model)\n"
    "   model\n"
    "   |> bright.update(update_state(_, msg))\n"
    "   // Here, selected is always the result state.field / 10 (the result from selector).\n"
    "   |> bright.lazy_compute(selector, fn (d, c, selected) { Computed(..c, field1: computation1(d, selected)) })\n"
    "   |> bright.lazy_compute(selector, fn (d, c, selected) { Computed(..c, field2: computation2(d, selected)) })\n"
    "   |> bright.lazy_compute(selector, fn (d, c, selected) { Computed(..c, field3: computation3(d, selected)) })\n"
    " }\n"
    "\n"
    " /// Use it with lazy_compute to recompute only when the field when\n"
    " /// { old_state.field / 10 } != { state.field / 10 }\n"
    " fn selector(d, _) {\n"
    "   d.field / 10\n"
    " }\n"
    " ```\n"
).
-spec lazy_compute(
    {bright(MVW, MVX), lustre@effect:effect(MWA)},
    fun((MVW) -> MWC),
    fun((MVW, MVX, MWC) -> MVX)
) -> {bright(MVW, MVX), lustre@effect:effect(MWA)}.
lazy_compute(Bright, Selector, Compute_) ->
    lazy_wrap(Bright, Selector, fun compute/2, Compute_).

-file("src/bright.gleam", 178).
?DOC(
    " Plugs in existing `state` like [`schedule`](#schedule) lazily. `lazy_schedule` accepts\n"
    " a selector as second argument. Each time the selector returns a different data\n"
    " than previous run, the computation will run. Otherwise, nothing happens.\n"
    " The scheduling function will receive `state`, `computed` and the selected\n"
    " data (i.e. the result from your selector function), in case accessing the\n"
    " selected data is needed.\n"
    "\n"
    " ```gleam\n"
    " pub fn update(model: Bright(state, computed), msg: Msg) {\n"
    "   use model <- bright.start(model)\n"
    "   model\n"
    "   |> bright.update(update_state(_, msg))\n"
    "   // selected is equal to state.field / 10 (the result from selector).\n"
    "   |> bright.lazy_schedule(selector, fn (state, computed, selected) {\n"
    "     use dispatch <- effect.from\n"
    "     case selected == 10 {\n"
    "       True -> dispatch(my_msg)\n"
    "       False -> Nil\n"
    "     }\n"
    "   })\n"
    " }\n"
    "\n"
    " /// Use it with lazy_schedule to recompute only when the field when\n"
    " /// { old_state.field / 10 } != { state.field / 10 }\n"
    " fn selector(state, _) {\n"
    "   state.field / 10\n"
    " }\n"
    " ```\n"
).
-spec lazy_schedule(
    {bright(MWG, MWH), lustre@effect:effect(MWK)},
    fun((MWG) -> MWM),
    fun((MWG, MWH, MWM) -> lustre@effect:effect(MWK))
) -> {bright(MWG, MWH), lustre@effect:effect(MWK)}.
lazy_schedule(Bright, Selector, Schedule_) ->
    lazy_wrap(Bright, Selector, fun schedule/2, Schedule_).