dream

-module(dream@servers@mist@handler).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/dream/servers/mist/handler.gleam").
-export([create/5]).

-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(
    " Request handler for Mist server\n"
    "\n"
    " This module provides handler creation functionality that converts\n"
    " Mist requests to Dream requests, routes them, and converts the\n"
    " response back to Mist format.\n"
    "\n"
    " This is an internal module used by the Dream server implementation.\n"
    " Most applications won't need to use this directly.\n"
).

-file("src/dream/servers/mist/handler.gleam", 59).
?DOC(
    " Create a request handler that converts Mist requests to Dream requests\n"
    "\n"
    " This function creates the main request handler used by the Mist server.\n"
    " It handles the complete request/response cycle:\n"
    "\n"
    " 1. Read the request body (with size limit)\n"
    " 2. Convert Mist request to Dream request format\n"
    " 3. Generate a request ID and update context\n"
    " 4. Route the request through the router\n"
    " 5. Convert Dream response back to Mist format\n"
    "\n"
    " ## Parameters\n"
    "\n"
    " - `router`: The application's router with all routes configured\n"
    " - `max_body_size`: Maximum allowed request body size in bytes\n"
    " - `template_context`: Template context to clone for each request\n"
    " - `services_instance`: Application services (database, cache, etc.)\n"
    " - `update_context`: Function to update context with request-specific data\n"
    "\n"
    " ## Returns\n"
    "\n"
    " A function that takes a Mist HTTP request and returns a Mist HTTP response.\n"
    " This function is what you pass to `mist.new()`.\n"
    "\n"
    " ## Example\n"
    "\n"
    " ```gleam\n"
    " // Internal use - normally called by dream.listen()\n"
    " let handler = handler.create(\n"
    "   my_router,\n"
    "   10_000_000,  // 10MB max body\n"
    "   my_context,\n"
    "   my_services,\n"
    "   fn(ctx, request_id) { MyContext(..ctx, request_id: request_id) }\n"
    " )\n"
    "\n"
    " mist.new(handler)\n"
    " |> mist.port(3000)\n"
    " |> mist.start()\n"
    " ```\n"
).
-spec create(
    dream@router:router(ADTH, ADTI),
    integer(),
    ADTH,
    ADTI,
    fun((ADTH, binary()) -> ADTH)
) -> fun((gleam@http@request:request(mist@internal@http:connection())) -> gleam@http@response:response(mist:response_data())).
create(
    Router,
    Max_body_size,
    Template_context,
    Services_instance,
    Update_context
) ->
    fun(Mist_req) ->
        Body_result = mist:read_body(Mist_req, Max_body_size),
        case Body_result of
            {ok, Req_with_body} ->
                {Dream_req, Request_id} = dream@servers@mist@request:convert(
                    Mist_req,
                    Req_with_body
                ),
                Request_context = Update_context(Template_context, Request_id),
                Dream_resp = dream@dream:route_request(
                    Router,
                    Dream_req,
                    Request_context,
                    Services_instance
                ),
                dream@servers@mist@response:convert(Dream_resp);

            {error, _} ->
                _pipe = gleam@http@response:new(400),
                gleam@http@response:set_body(
                    _pipe,
                    {bytes, gleam@bytes_tree:new()}
                )
        end
    end.