-module(clockwork_schedule).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/clockwork_schedule.gleam").
-export([new/3, with_logging/1, with_time_offset/2, stop/1, start/1, supervised/2]).
-export_type([schedule/0, message/0, state/0, scheduler/0]).

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

?MODULEDOC(
    "////////////////////////////////////////////////////////////////////////////////\n"
    "////////////////////////////////////////////////////////////////////////////////\n"
).

-type schedule() :: {schedule, gleam@erlang@process:subject(message())}.

-type message() :: run | stop.

-type state() :: {state,
        binary(),
        gleam@erlang@process:subject(message()),
        clockwork:cron(),
        fun(() -> nil),
        gleam@time@duration:duration()}.

-opaque scheduler() :: {scheduler,
        binary(),
        clockwork:cron(),
        fun(() -> nil),
        boolean(),
        gleam@time@duration:duration()}.

-file("src/clockwork_schedule.gleam", 120).
?DOC(
    " Creates a new scheduler configuration.\n"
    " \n"
    " ## Parameters\n"
    " \n"
    " - `id`: A unique identifier for this scheduler (used in logging)\n"
    " - `cron`: A cron expression defining when the job should run\n"
    " - `job`: The function to execute on each scheduled occurrence\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " import clockwork\n"
    " \n"
    " let assert Ok(cron) = clockwork.from_string(\"0 */2 * * *\")  // Every 2 hours\n"
    " let scheduler = clockwork_schedule.new(\"data_sync\", cron, fn() {\n"
    "   database.sync_remote_data()\n"
    " })\n"
    " ```\n"
).
-spec new(binary(), clockwork:cron(), fun(() -> nil)) -> scheduler().
new(Id, Cron, Job) ->
    {scheduler, Id, Cron, Job, false, {duration, 0, 0}}.

-file("src/clockwork_schedule.gleam", 139).
?DOC(
    " Enables logging for the scheduler.\n"
    " \n"
    " When logging is enabled, the scheduler will log:\n"
    " - When a job starts executing (with timestamp)\n"
    " - When the scheduler is stopped\n"
    " \n"
    " Logging uses the `logging` library and outputs at the `Info` level.\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " let scheduler = \n"
    "   clockwork_schedule.new(\"cleanup\", cron, cleanup_fn)\n"
    "   |> clockwork_schedule.with_logging()  // Enable logging\n"
    " ```\n"
).
-spec with_logging(scheduler()) -> scheduler().
with_logging(Scheduler) ->
    {scheduler,
        erlang:element(2, Scheduler),
        erlang:element(3, Scheduler),
        erlang:element(4, Scheduler),
        true,
        erlang:element(6, Scheduler)}.

-file("src/clockwork_schedule.gleam", 172).
?DOC(
    " Sets a time zone offset for the scheduler.\n"
    " \n"
    " By default, schedulers use the system's UTC offset. Use this function\n"
    " to run scheduled tasks in a specific time zone.\n"
    " \n"
    " ## Parameters\n"
    " \n"
    " - `scheduler`: The scheduler to configure\n"
    " - `offset`: The UTC offset as a Duration (positive for east, negative for west)\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " import gleam/time/duration\n"
    " \n"
    " // Configure for UTC+9 (Tokyo)\n"
    " let tokyo_offset = duration.from_hours(9)\n"
    " \n"
    " let scheduler = \n"
    "   clockwork_schedule.new(\"tokyo_job\", cron, job_fn)\n"
    "   |> clockwork_schedule.with_time_offset(tokyo_offset)\n"
    " \n"
    " // Configure for UTC-5 (New York)\n"
    " let ny_offset = duration.from_hours(-5)\n"
    " \n"
    " let ny_scheduler = \n"
    "   clockwork_schedule.new(\"ny_job\", cron, job_fn)\n"
    "   |> clockwork_schedule.with_time_offset(ny_offset)\n"
    " ```\n"
).
-spec with_time_offset(scheduler(), gleam@time@duration:duration()) -> scheduler().
with_time_offset(Scheduler, Offset) ->
    {scheduler,
        erlang:element(2, Scheduler),
        erlang:element(3, Scheduler),
        erlang:element(4, Scheduler),
        erlang:element(5, Scheduler),
        Offset}.

-file("src/clockwork_schedule.gleam", 360).
?DOC(
    " Gracefully stops a running scheduler.\n"
    " \n"
    " Sends a stop message to the scheduler, which will:\n"
    " 1. Cancel any pending job executions\n"
    " 2. Log a stop message (if logging is enabled)\n"
    " 3. Terminate the scheduler actor\n"
    " \n"
    " ## Parameters\n"
    " \n"
    " - `schedule`: The Schedule handle returned from `start` or `supervised`\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " let assert Ok(schedule) = clockwork_schedule.start(scheduler)\n"
    " \n"
    " // Run for some time...\n"
    " process.sleep(60_000)  // 1 minute\n"
    " \n"
    " // Gracefully stop\n"
    " clockwork_schedule.stop(schedule)\n"
    " ```\n"
    " \n"
    " ## Note\n"
    " \n"
    " After calling `stop`, the Schedule handle becomes invalid and cannot\n"
    " be reused. To restart scheduling, create and start a new scheduler.\n"
).
-spec stop(schedule()) -> nil.
stop(Schedule) ->
    gleam@erlang@process:send(erlang:element(2, Schedule), stop).

-file("src/clockwork_schedule.gleam", 388).
-spec enqueue_job(clockwork:cron(), state()) -> gleam@erlang@process:timer().
enqueue_job(Cron, State) ->
    Now = gleam@time@timestamp:system_time(),
    Next_occurrence = begin
        _pipe = clockwork:next_occurrence(Cron, Now, erlang:element(6, State)),
        _pipe@1 = gleam@time@timestamp:difference(Now, _pipe),
        _pipe@2 = gleam@time@duration:to_seconds_and_nanoseconds(_pipe@1),
        begin
            {Seconds, Nanoseconds} = _pipe@2,
            (Seconds * 1000) + (Nanoseconds div 1000000)
        end
    end,
    gleam@erlang@process:send_after(
        erlang:element(3, State),
        Next_occurrence,
        run
    ).

-file("src/clockwork_schedule.gleam", 364).
-spec loop(state(), message()) -> gleam@otp@actor:next(state(), any()).
loop(State, Message) ->
    case Message of
        run ->
            logging:log(
                info,
                <<<<<<"[CLOCKWORK] Running job: "/utf8,
                            (erlang:element(2, State))/binary>>/binary,
                        " at "/utf8>>/binary,
                    (begin
                        _pipe = gleam@time@timestamp:system_time(),
                        _pipe@1 = gleam@time@timestamp:add(
                            _pipe,
                            erlang:element(6, State)
                        ),
                        _pipe@2 = gleam@time@timestamp:to_unix_seconds(_pipe@1),
                        gleam_stdlib:float_to_string(_pipe@2)
                    end)/binary>>
            ),
            proc_lib:spawn_link(erlang:element(5, State)),
            enqueue_job(erlang:element(4, State), State),
            gleam@otp@actor:continue(State);

        stop ->
            logging:log(
                info,
                <<"[CLOCKWORK] Stopping job: "/utf8,
                    (erlang:element(2, State))/binary>>
            ),
            gleam@otp@actor:stop()
    end.

-file("src/clockwork_schedule.gleam", 185).
-spec start_actor(scheduler()) -> {ok,
        gleam@otp@actor:started(gleam@erlang@process:subject(message()))} |
    {error, gleam@otp@actor:start_error()}.
start_actor(Scheduler) ->
    case erlang:element(5, Scheduler) of
        true ->
            logging_ffi:configure();

        false ->
            nil
    end,
    _pipe@4 = gleam@otp@actor:new_with_initialiser(
        100,
        fun(Self) ->
            State = {state,
                erlang:element(2, Scheduler),
                Self,
                erlang:element(3, Scheduler),
                erlang:element(4, Scheduler),
                erlang:element(6, Scheduler)},
            Selector = begin
                _pipe = gleam_erlang_ffi:new_selector(),
                gleam@erlang@process:select(_pipe, Self)
            end,
            enqueue_job(erlang:element(3, Scheduler), State),
            _pipe@1 = gleam@otp@actor:initialised(State),
            _pipe@2 = gleam@otp@actor:selecting(_pipe@1, Selector),
            _pipe@3 = gleam@otp@actor:returning(_pipe@2, Self),
            {ok, _pipe@3}
        end
    ),
    _pipe@5 = gleam@otp@actor:on_message(_pipe@4, fun loop/2),
    gleam@otp@actor:start(_pipe@5).

-file("src/clockwork_schedule.gleam", 259).
?DOC(
    " Starts an unsupervised scheduler.\n"
    " \n"
    " This function starts a scheduler as a standalone actor that will run\n"
    " according to its cron expression. For production use, prefer `supervised`\n"
    " to run the scheduler under OTP supervision for better fault tolerance.\n"
    " \n"
    " ## Parameters\n"
    " \n"
    " - `scheduler`: The scheduler configuration to start\n"
    " \n"
    " ## Returns\n"
    " \n"
    " - `Ok(Schedule)`: A handle to control the running scheduler\n"
    " - `Error(actor.StartError)`: If the scheduler fails to start\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " import clockwork\n"
    " import clockwork_schedule\n"
    " \n"
    " pub fn main() {\n"
    "   let assert Ok(cron) = clockwork.from_string(\"*/30 * * * *\")  // Every 30 minutes\n"
    "   \n"
    "   let scheduler = \n"
    "     clockwork_schedule.new(\"metrics\", cron, fn() {\n"
    "       metrics.collect_and_report()\n"
    "     })\n"
    "     |> clockwork_schedule.with_logging()\n"
    "   \n"
    "   let assert Ok(schedule) = clockwork_schedule.start(scheduler)\n"
    "   \n"
    "   // The scheduler is now running\n"
    "   // Stop it when done:\n"
    "   clockwork_schedule.stop(schedule)\n"
    " }\n"
    " ```\n"
    " \n"
    " ## Note\n"
    " \n"
    " The scheduler will continue running until explicitly stopped with `stop`\n"
    " or until the process crashes. For automatic restart on failure, use\n"
    " `supervised` instead.\n"
).
-spec start(scheduler()) -> {ok, schedule()} |
    {error, gleam@otp@actor:start_error()}.
start(Scheduler) ->
    _pipe = start_actor(Scheduler),
    case _pipe of
        {ok, X} ->
            {ok, {schedule, erlang:element(3, X)}};

        {error, E} ->
            {error, E}
    end.

-file("src/clockwork_schedule.gleam", 322).
?DOC(
    " Creates a child specification for running the scheduler under OTP supervision.\n"
    " \n"
    " This is the recommended way to run schedulers in production. The scheduler\n"
    " will be automatically restarted if it crashes, ensuring your scheduled\n"
    " tasks remain reliable.\n"
    " \n"
    " ## Parameters\n"
    " \n"
    " - `scheduler`: The scheduler configuration\n"
    " - `schedule_receiver`: A subject to receive the Schedule handle once started\n"
    " \n"
    " ## Returns\n"
    " \n"
    " A `supervision.ChildSpec` that can be added to your supervision tree.\n"
    " \n"
    " ## Example\n"
    " \n"
    " ```gleam\n"
    " import clockwork\n"
    " import clockwork_schedule\n"
    " import gleam/erlang/process\n"
    " import gleam/otp/static_supervisor as supervisor\n"
    " \n"
    " pub fn main() {\n"
    "   let assert Ok(cron) = clockwork.from_string(\"0 * * * *\")  // Every hour\n"
    "   \n"
    "   let scheduler = \n"
    "     clockwork_schedule.new(\"hourly_task\", cron, fn() {\n"
    "       perform_hourly_maintenance()\n"
    "     })\n"
    "     |> clockwork_schedule.with_logging()\n"
    "   \n"
    "   // Create a receiver for the schedule handle\n"
    "   let schedule_receiver = process.new_subject()\n"
    "   \n"
    "   // Create the child spec\n"
    "   let schedule_child_spec = \n"
    "     clockwork_schedule.supervised(scheduler, schedule_receiver)\n"
    "   \n"
    "   // Add to supervision tree\n"
    "   let assert Ok(sup) =\n"
    "     supervisor.new()\n"
    "     |> supervisor.add(schedule_child_spec)\n"
    "     |> supervisor.start()\n"
    "   \n"
    "   // Receive the schedule handle\n"
    "   let assert Ok(schedule) = process.receive(schedule_receiver, 1000)\n"
    "   \n"
    "   // The scheduler is now running under supervision\n"
    "   process.sleep_forever()\n"
    " }\n"
    " ```\n"
    " \n"
    " ## Fault Tolerance\n"
    " \n"
    " If the scheduler crashes, the supervisor will automatically restart it.\n"
    " The new instance will recalculate the next occurrence and continue\n"
    " scheduling jobs as expected.\n"
).
-spec supervised(scheduler(), gleam@erlang@process:subject(schedule())) -> gleam@otp@supervision:child_specification(gleam@erlang@process:subject(message())).
supervised(Scheduler, Schedule_receiver) ->
    gleam@otp@supervision:worker(
        fun() ->
            gleam@result:'try'(
                start_actor(Scheduler),
                fun(Started) ->
                    gleam@erlang@process:send(
                        Schedule_receiver,
                        {schedule, erlang:element(3, Started)}
                    ),
                    {ok, Started}
                end
            )
        end
    ).