defmodule MicrowavepropWeb.ApiDocsLive do
  @moduledoc """
  Renders the Microwaveprop REST API documentation at `/docs/api`.

  Layout is modelled on the Tailwind UI "Protocol" template — a fixed
  left sidebar with section navigation and a two-column main column
  where prose sits next to a sticky code sample.
  """
  use MicrowavepropWeb, :live_view

  # ─────────────────────────────────────────────────────────────────────
  # Code samples are kept as module attributes so the HEEx template
  # stays readable. HEEx's attribute parser doesn't accept multi-line
  # heredoc sigils inline, so we bind once at compile time and reference
  # by name from the template.
  # ─────────────────────────────────────────────────────────────────────

  @sample_quickstart """
  curl -sS -X POST https://prop.w5isp.com/api/v1/auth/tokens \\
    -H "Content-Type: application/json" \\
    -d '{"email":"you@example.com","password":"...","name":"laptop"}'
  # => {"data": {...}, "token": "mwp_..."}

  TOKEN=mwp_...
  curl -sS -H "Authorization: Bearer $TOKEN" \\
    https://prop.w5isp.com/api/v1/me
  """

  @sample_auth_header "Authorization: Bearer mwp_AbCdEf123…"

  @sample_token_format """
  # 32 random bytes, URL-base64
  mwp_<43 chars>

  # Server stores SHA-256(token) only.
  """

  @sample_error_422 """
  {
    "type": "about:blank",
    "title": "validation_failed",
    "status": 422,
    "detail": "One or more fields are invalid.",
    "errors": {
      "callsign": ["must be 3-10 letters and digits"]
    }
  }
  """

  @sample_rate_headers """
  RateLimit-Limit: 600
  RateLimit-Remaining: 597
  RateLimit-Reset: 42
  """

  @sample_auth_tokens_request """
  curl -X POST https://prop.w5isp.com/api/v1/auth/tokens \\
    -H "Content-Type: application/json" \\
    -d '{
      "email": "you@example.com",
      "password": "your password",
      "name": "iPad",
      "expires_at": "2027-01-01T00:00:00Z"
    }'
  """

  @sample_auth_tokens_response """
  {
    "data": {
      "id": "01HX...",
      "name": "iPad",
      "inserted_at": "2026-05-09T12:34:00Z",
      "last_used_at": null,
      "expires_at": "2027-01-01T00:00:00Z",
      "revoked_at": null
    },
    "token": "mwp_AbCdEf..."
  }
  """

  @sample_me_get """
  curl -H "Authorization: Bearer $TOKEN" \\
    https://prop.w5isp.com/api/v1/me
  """

  @sample_me_patch """
  curl -X PATCH \\
    -H "Authorization: Bearer $TOKEN" \\
    -H "Content-Type: application/json" \\
    -d '{"home_grid":"EM12kx"}' \\
    https://prop.w5isp.com/api/v1/me
  """

  @sample_me_contacts """
  curl -H "Authorization: Bearer $TOKEN" \\
    "https://prop.w5isp.com/api/v1/me/contacts?per_page=20"
  """

  @sample_me_tokens_list """
  curl -H "Authorization: Bearer $TOKEN" \\
    https://prop.w5isp.com/api/v1/me/api-tokens
  """

  @sample_me_tokens_revoke """
  curl -X DELETE \\
    -H "Authorization: Bearer $TOKEN" \\
    https://prop.w5isp.com/api/v1/me/api-tokens/01HX...
  """

  @sample_monitor_create """
  curl -X POST \\
    -H "Authorization: Bearer $TOKEN" \\
    -H "Content-Type: application/json" \\
    -d '{"name":"shack-pi","grid":"EM12kx"}' \\
    https://prop.w5isp.com/api/v1/me/beacon-monitors
  """

  @sample_contacts_search """
  curl "https://prop.w5isp.com/api/v1/contacts?search=W5XD&per_page=25"
  """

  @sample_contact_submit """
  curl -X POST \\
    -H "Authorization: Bearer $TOKEN" \\
    -H "Content-Type: application/json" \\
    -d '{
      "station1": "W5XD",
      "station2": "K5XD",
      "qso_timestamp": "2026-05-08T12:34:00Z",
      "band": "10000",
      "grid1": "EM12",
      "grid2": "EM13",
      "mode": "CW"
    }' \\
    https://prop.w5isp.com/api/v1/contacts
  """

  @sample_beacon_submit """
  curl -X POST \\
    -H "Content-Type: application/json" \\
    -d '{
      "callsign": "WB5LUA/B",
      "frequency_mhz": 10368.025,
      "grid": "EM13qe",
      "power_w": 5
    }' \\
    https://prop.w5isp.com/api/v1/beacons
  """

  @sample_scores """
  curl "https://prop.w5isp.com/api/v1/scores?band=10000&lat=32.78&lon=-96.80"
  """

  @sample_forecast """
  curl "https://prop.w5isp.com/api/v1/forecast?band=10000&lat=32.78&lon=-96.80"
  """

  @sample_profile """
  curl https://prop.w5isp.com/api/v1/profiles/W5XD
  """

  @impl true
  def mount(_params, _session, socket) do
    {:ok,
     socket
     |> assign(:page_title, "API Documentation")
     |> assign(:sample_quickstart, @sample_quickstart)
     |> assign(:sample_auth_header, @sample_auth_header)
     |> assign(:sample_token_format, @sample_token_format)
     |> assign(:sample_error_422, @sample_error_422)
     |> assign(:sample_rate_headers, @sample_rate_headers)
     |> assign(:sample_auth_tokens_request, @sample_auth_tokens_request)
     |> assign(:sample_auth_tokens_response, @sample_auth_tokens_response)
     |> assign(:sample_me_get, @sample_me_get)
     |> assign(:sample_me_patch, @sample_me_patch)
     |> assign(:sample_me_contacts, @sample_me_contacts)
     |> assign(:sample_me_tokens_list, @sample_me_tokens_list)
     |> assign(:sample_me_tokens_revoke, @sample_me_tokens_revoke)
     |> assign(:sample_monitor_create, @sample_monitor_create)
     |> assign(:sample_contacts_search, @sample_contacts_search)
     |> assign(:sample_contact_submit, @sample_contact_submit)
     |> assign(:sample_beacon_submit, @sample_beacon_submit)
     |> assign(:sample_scores, @sample_scores)
     |> assign(:sample_forecast, @sample_forecast)
     |> assign(:sample_profile, @sample_profile)}
  end

  @impl true
  def render(assigns) do
    ~H"""
    <Layouts.app flash={@flash} current_scope={@current_scope} max_width="max-w-none">
      <div class="api-docs-shell">
        <aside class="api-docs-sidebar">
          <nav aria-label="API documentation">
            <.nav_group title="Guides">
              <.nav_link href="#introduction">Introduction</.nav_link>
              <.nav_link href="#quickstart">Quickstart</.nav_link>
              <.nav_link href="#authentication">Authentication</.nav_link>
              <.nav_link href="#errors">Errors</.nav_link>
              <.nav_link href="#rate-limiting">Rate limiting</.nav_link>
              <.nav_link href="#conventions">Conventions</.nav_link>
              <.nav_link href="#stability">Stability promise</.nav_link>
            </.nav_group>

            <.nav_group title="Endpoints">
              <.nav_link href="#auth-tokens">Auth tokens</.nav_link>
              <.nav_link href="#me">Current user</.nav_link>
              <.nav_link href="#me-collections">User collections</.nav_link>
              <.nav_link href="#me-tokens">API tokens</.nav_link>
              <.nav_link href="#me-monitors">Beacon monitors</.nav_link>
              <.nav_link href="#contacts">Contacts</.nav_link>
              <.nav_link href="#beacons">Beacons</.nav_link>
              <.nav_link href="#scores">Scores</.nav_link>
              <.nav_link href="#forecast">Forecast</.nav_link>
              <.nav_link href="#profiles">Profiles</.nav_link>
            </.nav_group>

            <.nav_group title="Reference">
              <.nav_link href="/docs/api/openapi.yaml">OpenAPI spec</.nav_link>
              <.nav_link href="/docs/api/README.md">Markdown source</.nav_link>
              <.nav_link href="/.well-known/api-catalog">Service catalog</.nav_link>
            </.nav_group>
          </nav>
        </aside>

        <main class="api-docs-main">
          <article class="api-docs-prose">
            <header id="introduction" class="api-docs-hero">
              <p class="api-docs-eyebrow">REST API · v1</p>
              <h1>Microwaveprop API</h1>
              <p class="api-docs-lead">
                The Microwaveprop public REST API exposes the read-and-write surface a
                regular user of the website has access to: contact (QSO) submission,
                beacon submission, beacon-monitor management, propagation queries,
                and profile management. Admin-only operations are deliberately
                excluded.
              </p>

              <dl class="api-docs-meta">
                <div>
                  <dt>Base URL</dt>
                  <dd><code>https://prop.w5isp.com/api/v1</code></dd>
                </div>
                <div>
                  <dt>Versioning</dt>
                  <dd>
                    Path-based (<code>/api/v1</code>). Breaking changes ship as <code>/api/v2</code>.
                  </dd>
                </div>
                <div>
                  <dt>Auth</dt>
                  <dd>
                    Opaque bearer tokens (<code>Authorization: Bearer mwp_…</code>).
                    Mint one from your
                    <.link navigate="/users/settings#api-tokens" class="api-docs-link">
                      account settings
                    </.link>
                    or programmatically at <code>POST /api/v1/auth/tokens</code>.
                  </dd>
                </div>
                <div>
                  <dt>Format</dt>
                  <dd>
                    <code>application/json</code>
                    requests and responses. Errors use <a
                      href="https://www.rfc-editor.org/rfc/rfc9457"
                      class="api-docs-link"
                    >
                      RFC 9457 problem+json
                    </a>.
                  </dd>
                </div>
                <div>
                  <dt>Spec</dt>
                  <dd>
                    <.link href="/docs/api/openapi.yaml" class="api-docs-link">
                      openapi.yaml
                    </.link>
                    (OpenAPI 3.1)
                  </dd>
                </div>
              </dl>
            </header>

            <.row id="quickstart">
              <:col>
                <h2>Quickstart</h2>
                <p>
                  Mint a long-lived bearer token once, then use it for every
                  subsequent call. Tokens are 32 random bytes, URL-base64 encoded
                  with an <code>mwp_</code> prefix so leak scanners can spot them.
                </p>
                <p class="api-docs-callout">
                  The interactive way to mint a token is the
                  <.link navigate="/users/settings#api-tokens" class="api-docs-link">
                    account settings page
                  </.link>
                  &mdash; the value is shown once. Keep it like a password.
                </p>
              </:col>
              <:code>
                <.code_block
                  title="Mint a token"
                  tag="POST"
                  label="/auth/tokens"
                  code={@sample_quickstart}
                />
              </:code>
            </.row>

            <.row id="authentication">
              <:col>
                <h2>Authentication</h2>
                <p>
                  Every endpoint that mutates state, or returns the
                  authenticated user's own data, requires a bearer token. Public
                  read endpoints accept an optional bearer that unlocks the
                  caller's private rows.
                </p>

                <h3>Endpoint auth matrix</h3>
                <table>
                  <thead>
                    <tr>
                      <th>Endpoint</th>
                      <th>Auth</th>
                      <th>Notes</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td><code>POST /auth/tokens</code></td>
                      <td>password</td>
                      <td>The only endpoint that accepts a password.</td>
                    </tr>
                    <tr>
                      <td><code>GET / PATCH /me</code></td>
                      <td>bearer</td>
                      <td>The user behind the bearer token.</td>
                    </tr>
                    <tr>
                      <td><code>POST /contacts</code></td>
                      <td>bearer</td>
                      <td>Regular user QSO submission.</td>
                    </tr>
                    <tr>
                      <td><code>GET /contacts</code></td>
                      <td>optional</td>
                      <td>Public; bearer reveals viewer-private rows.</td>
                    </tr>
                    <tr>
                      <td><code>GET /beacons</code></td>
                      <td>none</td>
                      <td>Approved beacons only.</td>
                    </tr>
                    <tr>
                      <td><code>POST /beacons</code></td>
                      <td>bearer</td>
                      <td>New beacons start unapproved.</td>
                    </tr>
                    <tr>
                      <td><code>GET /scores</code></td>
                      <td>none</td>
                      <td>Public read of propagation scores.</td>
                    </tr>
                    <tr>
                      <td><code>GET /profiles/:call</code></td>
                      <td>none</td>
                      <td>Public per-callsign profile.</td>
                    </tr>
                  </tbody>
                </table>

                <h3>Token lifecycle</h3>
                <ul>
                  <li>
                    Tokens may carry an optional <code>expires_at</code>
                    (ISO 8601 UTC). Without one they live until revoked.
                  </li>
                  <li>
                    <code>GET /me/api-tokens</code> lists every non-revoked token belonging to the
                    authenticated user (without plaintext).
                  </li>
                  <li>
                    <code>DELETE /me/api-tokens/:id</code>
                    revokes a token (soft delete &mdash; the row remains for
                    audit).
                  </li>
                  <li>
                    Revoking the token used by the current request immediately
                    invalidates every subsequent request from that token.
                  </li>
                </ul>
              </:col>
              <:code>
                <.code_block title="Authorization header" code={@sample_auth_header} />
                <.code_block title="Token format" code={@sample_token_format} />
              </:code>
            </.row>

            <.row id="errors">
              <:col>
                <h2>Errors</h2>
                <p>
                  All error responses follow
                  <a href="https://www.rfc-editor.org/rfc/rfc9457" class="api-docs-link">
                    RFC 9457
                  </a>
                  &mdash; a structured <code>application/problem+json</code>
                  body
                  with a stable <code>title</code>
                  field and per-field <code>errors</code>
                  on validation failures.
                </p>

                <table>
                  <thead>
                    <tr>
                      <th>Status</th>
                      <th>When</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td>400</td>
                      <td>Missing or malformed query / body parameter.</td>
                    </tr>
                    <tr>
                      <td>401</td>
                      <td>No / invalid / revoked / expired bearer token.</td>
                    </tr>
                    <tr>
                      <td>403</td>
                      <td>Authenticated, but the action is forbidden for the caller.</td>
                    </tr>
                    <tr>
                      <td>404</td>
                      <td>Resource not found, or hidden by privacy.</td>
                    </tr>
                    <tr>
                      <td>409</td>
                      <td>Duplicate &mdash; an equivalent resource already exists.</td>
                    </tr>
                    <tr>
                      <td>422</td>
                      <td>Validation failed; <code>errors</code> carries per-field messages.</td>
                    </tr>
                    <tr>
                      <td>429</td>
                      <td>
                        Rate limit exceeded; check <code>RateLimit-*</code>
                        + <code>Retry-After</code>.
                      </td>
                    </tr>
                    <tr>
                      <td>5xx</td>
                      <td>Bug. Please open an issue.</td>
                    </tr>
                  </tbody>
                </table>
              </:col>
              <:code>
                <.code_block title="422 validation failure" lang="json" code={@sample_error_422} />
              </:code>
            </.row>

            <.row id="rate-limiting">
              <:col>
                <h2>Rate limiting</h2>
                <p>
                  Every response carries the
                  <a href="https://datatracker.ietf.org/doc/rfc9651/" class="api-docs-link">
                    RFC 9651
                  </a>
                  <code>RateLimit-*</code>
                  headers so clients can self-throttle
                  before hitting a 429.
                </p>

                <table>
                  <thead>
                    <tr>
                      <th>Header</th>
                      <th>Meaning</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td><code>RateLimit-Limit</code></td>
                      <td>Requests permitted in the current window.</td>
                    </tr>
                    <tr>
                      <td><code>RateLimit-Remaining</code></td>
                      <td>Requests remaining in the current window.</td>
                    </tr>
                    <tr>
                      <td><code>RateLimit-Reset</code></td>
                      <td>Seconds until the window resets.</td>
                    </tr>
                    <tr>
                      <td><code>Retry-After</code></td>
                      <td>Sent on 429s; retry no sooner than this many seconds.</td>
                    </tr>
                  </tbody>
                </table>

                <h3>Defaults</h3>
                <table>
                  <thead>
                    <tr>
                      <th>Caller</th>
                      <th>Limit</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td>Anonymous (per IP)</td>
                      <td>60 req / minute</td>
                    </tr>
                    <tr>
                      <td>Authenticated (per token)</td>
                      <td>600 req / minute</td>
                    </tr>
                    <tr>
                      <td><code>POST /auth/tokens</code> (per IP)</td>
                      <td>30 req / minute</td>
                    </tr>
                  </tbody>
                </table>
              </:col>
              <:code>
                <.code_block title="Response headers" code={@sample_rate_headers} />
              </:code>
            </.row>

            <hr class="api-docs-divider" />

            <h2 class="api-docs-section-heading">Endpoint reference</h2>

            <.endpoint id="auth-tokens" method="POST" path="/auth/tokens">
              <:summary>Issue an API token</:summary>
              <:body>
                <p>
                  Prefer the
                  <.link navigate="/users/settings#api-tokens" class="api-docs-link">
                    account settings page
                  </.link>
                  for interactive use; this endpoint is here for scripts that need
                  to mint a token without leaving the terminal.
                </p>

                <h4>Request body</h4>
                <.properties>
                  <:property name="email" type="string" required>
                    Account email address.
                  </:property>
                  <:property name="password" type="string" required>
                    Account password.
                  </:property>
                  <:property name="name" type="string" required>
                    Human-readable label so you can identify the token later.
                  </:property>
                  <:property name="expires_at" type="datetime">
                    ISO 8601 UTC. Omit for a token that lives until revoked.
                  </:property>
                </.properties>
              </:body>
              <:code>
                <.code_block
                  title="Request"
                  tag="POST"
                  label="/auth/tokens"
                  code={@sample_auth_tokens_request}
                />
                <.code_block title="Response · 201" lang="json" code={@sample_auth_tokens_response} />
              </:code>
            </.endpoint>

            <.endpoint id="me" method="GET" path="/me">
              <:summary>The authenticated user</:summary>
              <:body>
                <p>
                  Returns the user behind the bearer token: callsign, name,
                  email, home QTH, and admin flag.
                </p>
                <p>
                  <code>PATCH /me</code>
                  accepts any subset of <code>home_grid</code>, <code>home_lat</code>, <code>home_lon</code>, <code>home_elevation_m</code>. Grid is auto-derived from
                  lat/lon and vice versa.
                </p>
              </:body>
              <:code>
                <.code_block title="Request" tag="GET" label="/me" code={@sample_me_get} />
                <.code_block title="Update home QTH" tag="PATCH" label="/me" code={@sample_me_patch} />
              </:code>
            </.endpoint>

            <.endpoint id="me-collections" method="GET" path="/me/contacts">
              <:summary>User-scoped collections</:summary>
              <:body>
                <p>
                  Two sibling endpoints return everything submitted under the
                  authenticated user's account, newest first:
                </p>
                <ul>
                  <li><code>GET /me/contacts</code> &mdash; every QSO submitted by the user.</li>
                  <li>
                    <code>GET /me/beacons</code>
                    &mdash; every beacon (approved or pending) submitted by the user.
                  </li>
                </ul>
                <p>
                  Both honour standard <code>page</code> + <code>per_page</code> pagination.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="List my contacts"
                  tag="GET"
                  label="/me/contacts"
                  code={@sample_me_contacts}
                />
              </:code>
            </.endpoint>

            <.endpoint id="me-tokens" method="GET" path="/me/api-tokens">
              <:summary>Manage your API tokens</:summary>
              <:body>
                <p>
                  <code>GET /me/api-tokens</code>
                  lists every non-revoked token belonging to the authenticated
                  user. The plaintext value is never returned &mdash; only the
                  metadata (id, name, timestamps).
                </p>
                <p>
                  <code>DELETE /me/api-tokens/:id</code>
                  revokes a token. The row is soft-deleted (its <code>revoked_at</code>
                  is set) and any in-flight request using it is invalidated on
                  the next call.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="List tokens"
                  tag="GET"
                  label="/me/api-tokens"
                  code={@sample_me_tokens_list}
                />
                <.code_block
                  title="Revoke a token"
                  tag="DELETE"
                  label="/me/api-tokens/:id"
                  code={@sample_me_tokens_revoke}
                />
              </:code>
            </.endpoint>

            <.endpoint id="me-monitors" method="GET" path="/me/beacon-monitors">
              <:summary>Beacon monitor stations</:summary>
              <:body>
                <p>
                  Distributed beacon monitor stations that report SNR samples
                  back to Microwaveprop. Each monitor row has a <code>token</code>
                  field &mdash; the credential the monitor program uses to
                  identify itself when reporting.
                </p>
                <h4>Operations</h4>
                <ul>
                  <li><code>GET /me/beacon-monitors</code> &mdash; list.</li>
                  <li>
                    <code>POST /me/beacon-monitors</code>
                    &mdash; create. Returns the new monitor's plaintext token (shown once).
                  </li>
                  <li><code>DELETE /me/beacon-monitors/:id</code> &mdash; revoke and remove.</li>
                </ul>
              </:body>
              <:code>
                <.code_block
                  title="Create a monitor"
                  tag="POST"
                  label="/me/beacon-monitors"
                  code={@sample_monitor_create}
                />
              </:code>
            </.endpoint>

            <.endpoint id="contacts" method="GET" path="/contacts">
              <:summary>Public contact (QSO) feed</:summary>
              <:body>
                <p>Paginated list of QSOs.</p>

                <h4>Query parameters</h4>
                <.properties>
                  <:property name="page" type="integer">
                    1-based. Defaults to <code>1</code>.
                  </:property>
                  <:property name="per_page" type="integer">
                    Defaults to <code>50</code>; capped at <code>200</code>.
                  </:property>
                  <:property name="search" type="string">
                    One or two callsigns; matches station1 or station2.
                  </:property>
                </.properties>

                <p>
                  When called with a bearer token, the user's own private
                  contacts are included in addition to the public set.
                </p>

                <p>
                  <code>GET /contacts/:id</code>
                  returns a single QSO. Private QSOs return 404 to non-owners.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="Search by callsign"
                  tag="GET"
                  label="/contacts"
                  code={@sample_contacts_search}
                />
              </:code>
            </.endpoint>

            <.endpoint method="POST" path="/contacts">
              <:summary>Submit a QSO</:summary>
              <:body>
                <p>
                  Create a new QSO under the authenticated user's account; their
                  email is recorded as <code>submitter_email</code>.
                </p>

                <h4>Required fields</h4>
                <.properties>
                  <:property name="station1" type="string" required>Submitter callsign.</:property>
                  <:property name="station2" type="string" required>
                    Other operator's callsign.
                  </:property>
                  <:property name="qso_timestamp" type="datetime" required>ISO 8601 UTC.</:property>
                  <:property name="band" type="string" required>
                    MHz integer string (<code>"10000"</code>, <code>"24000"</code>).
                  </:property>
                  <:property name="grid1" type="string" required>
                    4- or 6-character Maidenhead.
                  </:property>
                  <:property name="grid2" type="string" required>Other end's grid.</:property>
                  <:property name="mode" type="string" required>
                    Mode (e.g. <code>CW</code>, <code>SSB</code>).
                  </:property>
                </.properties>

                <h4>Optional fields</h4>
                <.properties>
                  <:property name="user_declared_prop_mode" type="string">
                    e.g. <code>tropo</code>, <code>aircraft_scatter</code>.
                  </:property>
                  <:property name="height1_ft" type="number">Antenna height above ground.</:property>
                  <:property name="height2_ft" type="number">Other end's antenna height.</:property>
                  <:property name="private" type="boolean">Hide from the public feed.</:property>
                  <:property name="notes" type="string">Free-form text.</:property>
                </.properties>

                <p>
                  A duplicate (same stations + same hour + same band) returns
                  <code>409 Conflict</code>
                  with the existing record in the <code>existing</code>
                  field.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="Submit a QSO"
                  tag="POST"
                  label="/contacts"
                  code={@sample_contact_submit}
                />
              </:code>
            </.endpoint>

            <.endpoint id="beacons" method="GET" path="/beacons">
              <:summary>Beacons</:summary>
              <:body>
                <p>
                  <code>GET /beacons</code>
                  lists approved beacons; <code>GET /beacons/:id</code>
                  reads a
                  single one.
                </p>
                <p>
                  <code>POST /beacons</code>
                  is unauthenticated &mdash; the new beacon is created in <code>approved=false</code>
                  state until an admin approves it via the website.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="Submit a beacon"
                  tag="POST"
                  label="/beacons"
                  code={@sample_beacon_submit}
                />
              </:code>
            </.endpoint>

            <.endpoint id="scores" method="GET" path="/scores">
              <:summary>Propagation score at a grid point</:summary>
              <:body>
                <p>
                  Returns the composite propagation score plus the per-factor
                  breakdown (rain, humidity, refractivity, &hellip;) for one
                  grid point at one band.
                </p>

                <h4>Query parameters</h4>
                <.properties>
                  <:property name="band" type="integer" required>MHz.</:property>
                  <:property name="lat" type="number" required>Decimal degrees.</:property>
                  <:property name="lon" type="number" required>Decimal degrees.</:property>
                  <:property name="valid_time" type="datetime">
                    ISO 8601 UTC. Defaults to the latest scored hour.
                  </:property>
                </.properties>

                <p>
                  <code>GET /scores/bands</code>
                  lists every band the engine scores for, with each band's
                  humidity-effect classification (beneficial / harmful).
                </p>
              </:body>
              <:code>
                <.code_block
                  title="Score for Dallas, 10 GHz"
                  tag="GET"
                  label="/scores"
                  code={@sample_scores}
                />
              </:code>
            </.endpoint>

            <.endpoint id="forecast" method="GET" path="/forecast">
              <:summary>18-hour score timeline</:summary>
              <:body>
                <p>
                  Returns the score at one grid point across the available
                  forecast horizon (currently 18 hours). Same <code>band</code>
                  + <code>lat</code>
                  + <code>lon</code>
                  parameters as <code>/scores</code>.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="18 h timeline"
                  tag="GET"
                  label="/forecast"
                  code={@sample_forecast}
                />
              </:code>
            </.endpoint>

            <.endpoint id="profiles" method="GET" path="/profiles/:callsign">
              <:summary>Public per-user profile</:summary>
              <:body>
                <p>
                  Public per-user profile: callsign, name, home QTH, all public
                  contacts involving the callsign, plus all approved beacons
                  submitted by the user. Email is <strong>not</strong> exposed.
                </p>
              </:body>
              <:code>
                <.code_block
                  title="Read a profile"
                  tag="GET"
                  label="/profiles/W5XD"
                  code={@sample_profile}
                />
              </:code>
            </.endpoint>

            <hr class="api-docs-divider" />

            <section id="conventions">
              <h2>Conventions</h2>
              <ul>
                <li>All timestamps are ISO 8601 UTC (<code>...Z</code>).</li>
                <li>All identifiers are UUIDv7 (binary_id) strings.</li>
                <li>Bands are integer MHz strings (<code>"10000"</code>, <code>"24000"</code>).</li>
                <li>Latitude / longitude are decimal degrees.</li>
                <li>
                  Maidenhead grids are 4- or 6-character (<code>EM12</code>, <code>EM12kx</code>).
                </li>
              </ul>
            </section>

            <section id="stability">
              <h2>Stability promise</h2>
              <ul>
                <li>Adding new fields to existing responses is non-breaking.</li>
                <li>Removing or renaming fields will only happen in a new <code>/api/vN</code>.</li>
                <li>Adding new endpoints to <code>/api/v1</code> is non-breaking.</li>
                <li>Tightening validation may produce new 422s; called out in the changelog.</li>
              </ul>
            </section>

            <section id="see-also">
              <h2>See also</h2>
              <ul>
                <li>
                  <.link href="/docs/api/openapi.yaml" class="api-docs-link">
                    openapi.yaml
                  </.link>
                  &mdash; the machine-readable spec.
                </li>
                <li>
                  <code>/.well-known/api-catalog</code> &mdash; RFC 9727 service descriptor (public).
                </li>
                <li>
                  <.link navigate="/algo" class="api-docs-link">/algo</.link>
                  &mdash; the scoring algorithm in detail.
                </li>
              </ul>
            </section>
          </article>
        </main>
      </div>
    </Layouts.app>
    """
  end

  # ---------------------------------------------------------------- components

  attr :title, :string, required: true
  slot :inner_block, required: true

  defp nav_group(assigns) do
    ~H"""
    <div class="api-docs-nav-group">
      <h3>{@title}</h3>
      <ul>{render_slot(@inner_block)}</ul>
    </div>
    """
  end

  attr :href, :string, required: true
  slot :inner_block, required: true

  defp nav_link(assigns) do
    ~H"""
    <li>
      <a href={@href}>{render_slot(@inner_block)}</a>
    </li>
    """
  end

  attr :id, :string, default: nil
  slot :col, required: true
  slot :code, required: true

  defp row(assigns) do
    ~H"""
    <section id={@id} class="api-docs-row">
      <div class="api-docs-row-prose">{render_slot(@col)}</div>
      <div class="api-docs-row-code">{render_slot(@code)}</div>
    </section>
    """
  end

  attr :id, :string, default: nil
  attr :method, :string, required: true
  attr :path, :string, required: true
  slot :summary, required: true
  slot :body, required: true
  slot :code, required: true

  defp endpoint(assigns) do
    ~H"""
    <section id={@id} class="api-docs-endpoint">
      <div class="api-docs-endpoint-prose">
        <div class="api-docs-eyebrow-row">
          <.method_tag method={@method} />
          <span class="api-docs-eyebrow-dot"></span>
          <code class="api-docs-eyebrow-path">{@path}</code>
        </div>
        <h3 class="api-docs-endpoint-title">{render_slot(@summary)}</h3>
        {render_slot(@body)}
      </div>
      <div class="api-docs-endpoint-code">{render_slot(@code)}</div>
    </section>
    """
  end

  attr :method, :string, required: true

  defp method_tag(assigns) do
    color =
      case String.upcase(assigns.method) do
        "GET" -> "is-get"
        "POST" -> "is-post"
        "PUT" -> "is-put"
        "PATCH" -> "is-patch"
        "DELETE" -> "is-delete"
        _ -> "is-zinc"
      end

    assigns = assign(assigns, :color, color)

    ~H"""
    <span class={"api-docs-method " <> @color}>{String.upcase(@method)}</span>
    """
  end

  attr :code, :string, required: true
  attr :title, :string, default: nil
  attr :tag, :string, default: nil
  attr :label, :string, default: nil
  attr :lang, :string, default: "bash"

  defp code_block(assigns) do
    assigns = assign(assigns, :code, dedent(assigns.code))

    ~H"""
    <figure class="api-docs-code">
      <figcaption :if={@title || @tag || @label} class="api-docs-code-caption">
        <span :if={@title} class="api-docs-code-title">{@title}</span>
        <span :if={@tag || @label} class="api-docs-code-meta">
          <.method_tag :if={@tag} method={@tag} />
          <code :if={@label}>{@label}</code>
        </span>
      </figcaption>
      <pre class={"api-docs-pre lang-" <> @lang}><code>{@code}</code></pre>
    </figure>
    """
  end

  # Strip uniform leading whitespace so source-side indentation is dropped.
  defp dedent(text) when is_binary(text) do
    text = String.trim_trailing(text)
    lines = String.split(text, "\n")

    indents =
      lines
      |> Enum.reject(&(String.trim(&1) == ""))
      |> Enum.map(&leading_spaces/1)

    case indents do
      [] -> text
      _ -> Enum.map_join(lines, "\n", &drop_prefix(&1, Enum.min(indents)))
    end
  end

  defp leading_spaces(line) do
    line
    |> String.graphemes()
    |> Enum.take_while(&(&1 == " "))
    |> length()
  end

  defp drop_prefix(line, n) do
    case line do
      "" -> ""
      _ -> String.slice(line, min(n, String.length(line))..-1//1)
    end
  end

  slot :property do
    attr :name, :string, required: true
    attr :type, :string, required: true
    attr :required, :boolean
  end

  defp properties(assigns) do
    ~H"""
    <dl class="api-docs-properties">
      <div :for={prop <- @property} class="api-docs-property">
        <dt>
          <code class="api-docs-property-name">{prop.name}</code>
          <span class="api-docs-property-type">{prop.type}</span>
          <span :if={Map.get(prop, :required)} class="api-docs-property-required">required</span>
        </dt>
        <dd>{render_slot(prop)}</dd>
      </div>
    </dl>
    """
  end
end