defmodule MicrowavepropWeb.SubmitLive do
  @moduledoc false
  use MicrowavepropWeb, :live_view
  use LiveStash

  alias Microwaveprop.Radio
  alias Microwaveprop.Radio.Contact
  alias Microwaveprop.Radio.CsvImport
  alias Microwaveprop.Workers.ContactWeatherEnqueueWorker

  @band_options [
    {"1296 MHz", "1296"},
    {"2304 MHz", "2304"},
    {"3456 MHz", "3456"},
    {"5760 MHz", "5760"},
    {"10 GHz", "10000"},
    {"24 GHz", "24000"},
    {"47 GHz", "47000"},
    {"68 GHz", "68000"},
    {"76 GHz", "75000"},
    {"122 GHz", "122000"},
    {"134 GHz", "134000"},
    {"241 GHz", "241000"}
  ]

  @mode_options ~w(CW SSB FM FT8 FT4)

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

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

      _ ->
        changeset = Radio.change_contact(%Contact{})

        {:ok,
         assign(socket,
           page_title: "Submit Contact",
           form: to_form(changeset),
           band_options: @band_options,
           mode_options: @mode_options,
           submitted_at: nil,
           active_tab: :single,
           csv_result: nil,
           csv_email: ""
         )}
    end
  end

  @impl true
  def handle_event("switch_tab", %{"tab" => tab}, socket) do
    socket = assign(socket, active_tab: String.to_existing_atom(tab))
    {:noreply, LiveStash.stash_assigns(socket, [:active_tab])}
  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

  # 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
      case Radio.create_contact(contact_params) 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, changeset} ->
          {:noreply, assign(socket, form: to_form(changeset))}
      end
    end
  end

  def handle_event("upload_csv", %{"submitter_email" => email}, socket) do
    if String.trim(email) == "" do
      {:noreply, put_flash(socket, :error, "Email is required for CSV upload")}
    else
      uploaded_contents =
        consume_uploaded_entries(socket, :csv, fn %{path: path}, _entry ->
          {:ok, File.read!(path)}
        end)

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

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

  def handle_event("reset_csv", _params, socket) do
    {:noreply, assign(socket, csv_result: nil)}
  end

  defp handle_csv_import(content, email, socket) do
    case CsvImport.import(content, email) do
      {:ok, result} ->
        {:noreply, assign(socket, csv_result: result, csv_email: email)}

      {: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")}
    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

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

      <div class="bg-info/10 border border-info/30 rounded-box p-4 mb-6 text-sm leading-relaxed">
        <p class="font-semibold text-info mb-1">Every contact matters</p>
        <p>
          Our propagation model improves with real-world data. Each verified microwave contact
          you submit is matched against atmospheric conditions at the time of your contact,
          helping us calibrate predictions for all bands from 10 GHz to 241 GHz. The more contacts
          we have, the better our forecasts get for everyone.
        </p>
      </div>

      <div class="bg-base-200 rounded-box p-4 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 class="flex gap-1 bg-base-200 rounded-lg p-1 mb-6 w-fit">
        <button
          class={[
            "px-4 py-2 text-sm font-medium rounded-md transition-colors",
            if(@active_tab == :single,
              do: "bg-primary text-primary-content",
              else: "hover:bg-base-300"
            )
          ]}
          phx-click="switch_tab"
          phx-value-tab="single"
        >
          Single Contact
        </button>
        <button
          class={[
            "px-4 py-2 text-sm font-medium rounded-md transition-colors",
            if(@active_tab == :csv, do: "bg-primary text-primary-content", else: "hover:bg-base-300")
          ]}
          phx-click="switch_tab"
          phx-value-tab="csv"
        >
          Upload CSV
        </button>
      </div>

      <%= if @active_tab == :single do %>
        <.single_contact_form form={@form} band_options={@band_options} mode_options={@mode_options} />
      <% else %>
        <%= if @csv_result do %>
          <.csv_results result={@csv_result} />
        <% else %>
          <.csv_upload_form uploads={@uploads} />
        <% 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-2 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[:station2]} type="text" label="Station 2" placeholder="K5TR" required />
        <.input
          field={@form[:grid2]}
          type="text"
          label="Grid 2"
          placeholder="EM00cd"
          phx-debounce="blur"
          required
        />
      </div>

      <p class="text-sm text-base-content/60 -mt-2">
        Be as specific as possible with grid squares (6 characters preferred, e.g. EM12kp).
      </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="Select mode"
          options={@mode_options}
          required
        />
        <.input field={@form[:qso_timestamp]} type="datetime-local" label="Timestamp (UTC)" required />
      </div>

      <.input
        field={@form[:submitter_email]}
        type="email"
        label="Your Email"
        placeholder="you@example.com"
        required
      />

      <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

  defp csv_upload_form(assigns) do
    ~H"""
    <div class="space-y-6">
      <div class="bg-base-200 rounded-box p-4 text-sm">
        <p class="mb-2">
          Upload a CSV file with multiple contacts. Required columns:
        </p>
        <code class="text-xs">station1, station2, grid1, grid2, band, mode, qso_timestamp</code>
        <ul class="list-disc list-inside mt-2 space-y-1 text-base-content/60">
          <li>
            Timestamps in most formats accepted (e.g. <code>2024-06-15T14:30:00Z</code>, <code>6/15/2024 2:30 PM</code>, <code>2024-06-15 14:30</code>). All times assumed UTC.
          </li>
          <li>
            Grid squares should be as detailed as possible (6 characters preferred, e.g. EM12kp)
          </li>
          <li>Band in MHz (e.g. 10000, 24000)</li>
        </ul>
        <p class="mt-2">
          <a href="/downloads/sample_contacts.csv" download class="link link-primary">
            <.icon name="hero-arrow-down-tray" class="w-4 h-4" /> Download sample CSV
          </a>
        </p>
      </div>

      <form id="csv-upload-form" phx-submit="upload_csv" phx-change="validate_csv" class="space-y-4">
        <div class="fieldset mb-2">
          <label>
            <span class="label mb-1">CSV File</span>
            <.live_file_input upload={@uploads.csv} class="file-input file-input-bordered w-full" />
          </label>
        </div>

        <div class="fieldset mb-2">
          <label>
            <span class="label mb-1">Your Email</span>
            <input
              type="email"
              name="submitter_email"
              class="w-full input"
              placeholder="you@example.com"
              value=""
            />
          </label>
        </div>

        <div class="mt-6">
          <button type="submit" class="btn btn-primary btn-lg w-full sm:w-auto">
            <.icon name="hero-arrow-up-tray" class="w-5 h-5" /> Upload Contacts
          </button>
        </div>
      </form>
    </div>
    """
  end

  defp csv_results(assigns) do
    ~H"""
    <div class="space-y-4">
      <%= if length(@result.imported) > 0 do %>
        <div class="alert alert-success">
          <.icon name="hero-check-circle" class="w-5 h-5" />
          <span>
            {length(@result.imported)} {if length(@result.imported) == 1,
              do: "contact",
              else: "contacts"} imported successfully
          </span>
        </div>
      <% end %>

      <%= if length(@result.errors) > 0 do %>
        <div class="alert alert-error">
          <.icon name="hero-exclamation-triangle" class="w-5 h-5" />
          <span>
            {length(@result.errors)} {if length(@result.errors) == 1, do: "row", else: "rows"} had errors
          </span>
        </div>

        <div class="overflow-x-auto">
          <table class="table table-sm">
            <thead>
              <tr>
                <th>Row</th>
                <th>Errors</th>
              </tr>
            </thead>
            <tbody>
              <%= for {row_num, messages} <- @result.errors do %>
                <tr>
                  <td class="font-mono">Row {row_num}</td>
                  <td>
                    <%= for msg <- messages do %>
                      <div>{msg}</div>
                    <% end %>
                  </td>
                </tr>
              <% end %>
            </tbody>
          </table>
        </div>
      <% end %>

      <button type="button" class="btn btn-outline" phx-click="reset_csv">
        Upload another
      </button>
    </div>
    """
  end
end