defmodule MicrowavepropWeb.SubmitLive do
  @moduledoc "`/submit` QSO submission form; enqueues enrichment jobs on save."
  use MicrowavepropWeb, :live_view
  use LiveStash, stored_keys: [:active_tab]

  import MicrowavepropWeb.LiveHelpers, only: [current_user: 1]
  import MicrowavepropWeb.SubmitLive.AdifUploadComponent
  import MicrowavepropWeb.SubmitLive.CsvUploadComponent
  import MicrowavepropWeb.SubmitLive.PreviewComponent

  alias Microwaveprop.Propagation.BandConfig
  alias Microwaveprop.Radio
  alias Microwaveprop.Radio.AdifImport
  alias Microwaveprop.Radio.Contact
  alias Microwaveprop.Radio.CsvImport
  alias Microwaveprop.Workers.ContactWeatherEnqueueWorker

  @mode_options ~w(CW SSB FM FT8 FT4 Q65)

  @impl true
  def mount(_params, _session, socket) do
    socket =
      socket
      |> allow_upload(:csv,
        accept: ~w(.csv),
        max_entries: 1,
        max_file_size: 10_000_000,
        auto_upload: false
      )
      |> allow_upload(:adif,
        accept: :any,
        max_entries: 1,
        max_file_size: 10_000_000,
        auto_upload: false
      )

    changeset = Radio.change_contact(%Contact{})

    socket =
      assign(socket,
        page_title: "Submit Contact",
        form: to_form(changeset),
        band_options: BandConfig.band_options(),
        mode_options: @mode_options,
        submitted_at: nil,
        active_tab: :single,
        csv_preview: nil,
        csv_email: ""
      )

    case LiveStash.recover_state(socket) do
      {:recovered, socket} ->
        {:ok, socket}

      _ ->
        {:ok, socket}
    end
  end

  @valid_tabs ~w(single csv adif)a

  @impl true
  def handle_event("switch_tab", %{"tab" => tab}, socket) do
    case Enum.find(@valid_tabs, &(Atom.to_string(&1) == tab)) do
      nil ->
        # Stale or forged client event — ignore instead of crashing the
        # LiveView via String.to_existing_atom/1.
        {:noreply, socket}

      atom ->
        socket = assign(socket, active_tab: atom)
        {:noreply, MicrowavepropWeb.LiveStashGuard.stash(socket)}
    end
  end

  def handle_event("validate", %{"contact" => contact_params}, socket) do
    changeset =
      %Contact{}
      |> Radio.change_contact(contact_params)
      |> Map.put(:action, :validate)

    {:noreply, assign(socket, form: to_form(changeset))}
  end

  def handle_event("validate_csv", _params, socket) do
    {:noreply, socket}
  end

  def handle_event("validate_adif", _params, socket) do
    {:noreply, socket}
  end

  @max_import_rows 2_000

  # Minimum milliseconds between submissions per LiveView session.
  # For broader IP-based rate limiting, use a reverse proxy (nginx limit_req, Cloudflare).
  @submission_cooldown_ms 30_000

  def handle_event("save", %{"contact" => contact_params}, socket) do
    if recently_submitted?(socket) do
      {:noreply, put_flash(socket, :error, "Please wait before submitting another contact.")}
    else
      {contact_params, user_id} = merge_user_params(contact_params, socket)

      case Radio.create_contact(contact_params, user_id) do
        {:ok, contact} ->
          ContactWeatherEnqueueWorker.enqueue_for_contact(contact)

          {:noreply,
           socket
           |> assign(submitted_at: System.monotonic_time(:millisecond))
           |> put_flash(:info, "Contact submitted successfully!")
           |> push_navigate(to: ~p"/contacts/#{contact.id}")}

        {:error, :duplicate, existing} ->
          {:noreply,
           socket
           |> put_flash(
             :error,
             "A matching contact already exists: #{existing.station1} ↔ #{existing.station2} on #{existing.band} MHz"
           )
           |> push_navigate(to: ~p"/contacts/#{existing.id}")}

        {:error, changeset} ->
          {:noreply, assign(socket, form: to_form(changeset))}
      end
    end
  end

  def handle_event("upload_csv", params, socket) do
    cond do
      recently_submitted?(socket) ->
        {:noreply, put_flash(socket, :error, "Please wait before submitting another contact.")}

      !current_user(socket.assigns) ->
        {:noreply, put_flash(socket, :error, "Please sign in to upload files.")}

      true ->
        user = current_user(socket.assigns)
        email = user.email
        private = Map.get(params, "private") == "true"

        uploaded_contents =
          consume_uploaded_entries(socket, :csv, fn %{path: path}, _entry ->
            {:ok, File.read!(path)}
          end)

        case uploaded_contents do
          [content] ->
            handle_csv_preview(content, email, private, socket)

          [] ->
            {:noreply, put_flash(socket, :error, "Please select a CSV file")}
        end
    end
  end

  def handle_event("cancel_csv_upload", %{"ref" => ref}, socket) do
    {:noreply, cancel_upload(socket, :csv, ref)}
  end

  def handle_event("upload_adif", params, socket) do
    cond do
      recently_submitted?(socket) ->
        {:noreply, put_flash(socket, :error, "Please wait before submitting another contact.")}

      !current_user(socket.assigns) ->
        {:noreply, put_flash(socket, :error, "Please sign in to upload files.")}

      true ->
        user = current_user(socket.assigns)
        email = user.email
        private = Map.get(params, "private") == "true"

        uploaded_contents =
          consume_uploaded_entries(socket, :adif, fn %{path: path}, _entry ->
            {:ok, File.read!(path)}
          end)

        case uploaded_contents do
          [content] ->
            handle_adif_preview(content, email, private, socket)

          [] ->
            {:noreply, put_flash(socket, :error, "Please select an ADIF file")}
        end
    end
  end

  def handle_event("cancel_adif_upload", %{"ref" => ref}, socket) do
    {:noreply, cancel_upload(socket, :adif, ref)}
  end

  def handle_event("confirm_csv", _params, socket) do
    cond do
      recently_submitted?(socket) ->
        {:noreply, put_flash(socket, :error, "Please wait before submitting another contact.")}

      !current_user(socket.assigns) ->
        {:noreply, put_flash(socket, :error, "Please sign in to upload files.")}

      true ->
        case socket.assigns.csv_preview do
          %{valid: valid_rows, refinements: refinements} = preview
          when valid_rows != [] or refinements != [] ->
            private = socket.assigns[:csv_private] || false
            {:ok, run_id} = CsvImport.enqueue(preview, socket.assigns.csv_email, private: private)

            {:noreply,
             socket
             |> assign(csv_preview: nil, csv_private: false)
             |> push_navigate(to: ~p"/imports/#{run_id}")}

          _ ->
            {:noreply, put_flash(socket, :error, "Nothing to import.")}
        end
    end
  end

  def handle_event("cancel_csv", _params, socket) do
    {:noreply, assign(socket, csv_preview: nil, csv_private: false)}
  end

  defp handle_adif_preview(content, email, private, socket) do
    case AdifImport.preview(content, email) do
      {:ok, preview} ->
        if preview.total_rows > @max_import_rows do
          {:noreply, put_flash(socket, :error, "ADIF file has too many rows (max #{@max_import_rows}).")}
        else
          {:noreply, assign(socket, csv_preview: preview, csv_email: email, csv_private: private)}
        end

      {:error, :no_records} ->
        {:noreply, put_flash(socket, :error, "ADIF file contains no records")}

      {:error, :too_many_rows} ->
        {:noreply, put_flash(socket, :error, "ADIF file has too many rows (max #{@max_import_rows}).")}
    end
  end

  defp handle_csv_preview(content, email, private, socket) do
    case CsvImport.preview(content, email) do
      {:ok, preview} ->
        if preview.total_rows > @max_import_rows do
          {:noreply, put_flash(socket, :error, "CSV file has too many rows (max #{@max_import_rows}).")}
        else
          {:noreply, assign(socket, csv_preview: preview, csv_email: email, csv_private: private)}
        end

      {:error, :empty_csv} ->
        {:noreply, put_flash(socket, :error, "CSV file is empty")}

      {:error, :no_data_rows} ->
        {:noreply, put_flash(socket, :error, "CSV file has no data rows")}

      {:error, :too_many_rows} ->
        {:noreply, put_flash(socket, :error, "CSV file has too many rows (max #{@max_import_rows}).")}
    end
  end

  defp recently_submitted?(socket) do
    case socket.assigns.submitted_at do
      nil -> false
      ts -> System.monotonic_time(:millisecond) - ts < @submission_cooldown_ms
    end
  end

  defp merge_user_params(params, socket) do
    case current_user(socket.assigns) do
      %{id: user_id, email: user_email} ->
        {Map.put(params, "submitter_email", user_email), user_id}

      _ ->
        {params, nil}
    end
  end

  @impl true
  def render(assigns) do
    ~H"""
    <Layouts.app flash={@flash} current_scope={@current_scope}>
      <.header>
        Submit Contact
        <:subtitle>Help us build a better propagation model</:subtitle>
      </.header>

      <div class="alert alert-info mb-6 text-sm leading-relaxed">
        <div>
          <p class="font-semibold mb-1">Every contact matters</p>
          <p>
            Our propagation model improves with real-world data. Each verified contact
            you submit is matched against atmospheric conditions at the time of your contact,
            helping us calibrate predictions for all amateur bands from 50 MHz and up. The
            more contacts we have, the better our forecasts get for everyone.
          </p>
        </div>
      </div>

      <div class="alert mb-6 text-sm leading-relaxed">
        <p>
          Your contact will be available on the
          <.link navigate="/contacts" class="link link-primary">contacts page</.link>
          shortly after submission, with terrain analysis, atmospheric data, and propagation scoring
          added automatically.
        </p>
      </div>

      <div role="tablist" class="tabs tabs-box mb-6">
        <button
          role="tab"
          class={["tab", @active_tab == :single && "tab-active"]}
          phx-click="switch_tab"
          phx-value-tab="single"
        >
          Single Contact
        </button>
        <%= if current_user(assigns) do %>
          <button
            role="tab"
            class={["tab", @active_tab == :csv && "tab-active"]}
            phx-click="switch_tab"
            phx-value-tab="csv"
          >
            Upload CSV
          </button>
          <button
            role="tab"
            class={["tab", @active_tab == :adif && "tab-active"]}
            phx-click="switch_tab"
            phx-value-tab="adif"
          >
            Upload ADIF
          </button>
        <% end %>
      </div>

      <%= case @active_tab do %>
        <% :single -> %>
          <.single_contact_form
            form={@form}
            band_options={@band_options}
            mode_options={@mode_options}
            current_user={current_user(assigns)}
          />
        <% :csv -> %>
          <%= if @csv_preview do %>
            <.csv_preview preview={@csv_preview} />
          <% else %>
            <.csv_upload_form uploads={@uploads} current_user={current_user(assigns)} />
          <% end %>
        <% :adif -> %>
          <%= if @csv_preview do %>
            <.csv_preview preview={@csv_preview} />
          <% else %>
            <.adif_upload_form uploads={@uploads} current_user={current_user(assigns)} />
          <% end %>
      <% end %>
    </Layouts.app>
    """
  end

  defp single_contact_form(assigns) do
    ~H"""
    <.form for={@form} id="contact-form" phx-change="validate" phx-submit="save" class="space-y-4">
      <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
        <.input field={@form[:station1]} type="text" label="Station 1" placeholder="W5XD" required />
        <.input
          field={@form[:grid1]}
          type="text"
          label="Grid 1"
          placeholder="EM12kp"
          phx-debounce="blur"
          required
        />
        <.input
          field={@form[:height1_ft]}
          type="number"
          label="Height 1 (ft AGL)"
          min="0"
          max="1000"
          placeholder="Optional"
        />
        <.input field={@form[:station2]} type="text" label="Station 2" placeholder="K5TR" required />
        <.input
          field={@form[:grid2]}
          type="text"
          label="Grid 2"
          placeholder="EM00cd"
          phx-debounce="blur"
          required
        />
        <.input
          field={@form[:height2_ft]}
          type="number"
          label="Height 2 (ft AGL)"
          min="0"
          max="1000"
          placeholder="Optional"
        />
      </div>

      <p class="text-sm text-base-content/60 -mt-2">
        Be as specific as possible with grid squares (8 characters preferred, e.g. EM12kp37).
        Antenna heights are optional but improve terrain-clearance analysis.
      </p>

      <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
        <.input
          field={@form[:band]}
          type="select"
          label="Band"
          prompt="Select band"
          options={@band_options}
          required
        />
        <.input
          field={@form[:mode]}
          type="select"
          label="Mode"
          prompt="Optional"
          options={@mode_options}
        />
        <.input
          field={@form[:qso_timestamp]}
          type="text"
          label="Timestamp (UTC, 24h)"
          placeholder="YYYY-MM-DD HH:MM"
          pattern="\d{4}-\d{2}-\d{2}[T ]\d{2}:\d{2}(:\d{2})?Z?"
          required
        />
      </div>

      <%= if @current_user do %>
        <input
          type="hidden"
          name="contact[submitter_email]"
          value={@current_user.email}
        />
      <% else %>
        <.input
          field={@form[:submitter_email]}
          type="email"
          label="Your Email"
          placeholder="you@example.com"
          required
        />
      <% end %>

      <.input
        field={@form[:notes]}
        type="textarea"
        label="Notes (optional)"
        placeholder="Operator notes — propagation mode, weather, equipment, QSO commentary…"
        rows="3"
        maxlength="2000"
      />

      <div class="mt-4">
        <.input
          field={@form[:private]}
          type="checkbox"
          label="Private — only visible to me and administrators"
        />
      </div>

      <div class="mt-6">
        <.button phx-disable-with="Submitting..." class="btn btn-primary btn-lg w-full sm:w-auto">
          <.icon name="hero-arrow-up-tray" class="w-5 h-5" /> Submit Contact
        </.button>
      </div>
    </.form>
    """
  end
end