-- routes_admin.lua — login/logout, dashboard, editor, settings, uploads.

local fm     = require "fm"
local db     = require "db"
local render = require "render"
local md     = require "md"
local auth   = require "auth"
local web    = require "web"
local config = require "config"
local media  = require "media"

local route = web.route

local FORBIDDEN_BODY =
  '<div class="error-page"><p>Invalid request token. Please go back and try again.</p></div>'

local function forbidden()
  SetStatus(403)
  return render.respond("Forbidden", FORBIDDEN_BODY)
end

-- ── Login / logout ────────────────────────────────────────────────────

local login_rate_ok = web.make_limiter(5, 900)  -- 5 attempts per IP per 15 min

local LOGIN_ERRORS = {
  token = "Invalid request token. Please try again.",
  rate  = "Too many login attempts. Please wait before trying again.",
  cred  = "Incorrect password.",
}

route(fm.GET "/login", function(r)
  if auth.has_session() then
    return web.redirect("/edit")
  end

  local tok     = web.csrf_token()
  local err_msg = LOGIN_ERRORS[r.params.e or ""] or ""
  local err_html = err_msg ~= ""
    and '<div class="login-error"><p>' .. err_msg .. '</p></div>'
    or  ""

  local body =
    '<div class="login-wrap">'
    .. '<h1>Admin Login</h1>'
    .. err_html
    .. '<form method="post" action="/login">'
    .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'
    .. '<div class="form-group">'
    .. '<label for="lp">Password</label>'
    .. '<input type="password" id="lp" name="password" autocomplete="current-password">'
    .. '</div>'
    .. '<button type="submit" class="btn btn-primary">SIGN_IN</button>'
    .. '</form>'
    .. '</div>'

  return render.respond("Login", body)
end)

route(fm.POST "/login", function(r)
  if not web.csrf_check(r) then
    return web.redirect("/login?e=token")
  end

  local ip = web.client_ip()
  if not login_rate_ok(ip) then
    return web.redirect("/login?e=rate")
  end

  local token, err = auth.login(r.params.password or "")
  if not token then
    Log(kLogWarn, "login failed for " .. ip .. ": " .. tostring(err))
    return web.redirect("/login?e=cred")
  end

  -- SetStatus MUST come before SetCookie/SetHeader: SetStatus resets the
  -- response buffer, discarding any headers set before it.
  SetStatus(302)
  SetHeader("Location", "/edit")
  SetCookie("session", token, {
    MaxAge   = 7 * 24 * 3600,
    Path     = "/",
    HttpOnly = true,
    SameSite = "Strict",
  })
  return " "
end)

route(fm.POST "/logout", function(r)
  local tok = GetCookie("session")
  if tok then auth.logout(tok) end
  SetStatus(302)
  SetHeader("Location", "/")
  SetCookie("session", "", {MaxAge = 0, Path = "/", HttpOnly = true, SameSite = "Strict"})
  return " "
end)

-- ── Editor form (shared by GET /edit/new and GET /edit/:id) ───────────
-- item = nil for new, or a DB row for editing.
-- kind = "blog" | "wiki" | "docs" (used when item is nil).
-- err  = optional error string to display above the form.
local function editor_page(item, kind, err)
  local is_new  = item == nil
  kind          = (item and item.kind) or kind or "blog"
  local action  = is_new and "/edit/new" or ("/edit/" .. item.id)

  local title_val   = (item and item.title)   or ""
  local slug_val    = (item and item.slug)    or ""
  local body_val    = (item and item.body)    or ""
  local tags_val    = (item and item.tags)    or ""
  local summary_val = (item and item.summary) or ""
  local pub_checked = (item and item.published == 1) and " checked" or ""

  local kind_label  = kind:sub(1, 1):upper() .. kind:sub(2)
  local page_title  = is_new and ("New " .. kind_label)
                              or ("Edit: " .. title_val)

  local err_html = err
    and '<div class="editor-error"><p>' .. EscapeHtml(err) .. '</p></div>'
    or  ""

  local preview_html = body_val ~= ""
    and md.render(body_val)
    or  '<p class="text-muted">Preview will appear here\226\128\166</p>'

  -- View-live link (edit mode only, shown when slug is known).
  local view_link = (not is_new and slug_val ~= "")
    and ('<a href="/' .. EscapeHtml(kind) .. '/' .. EscapeHtml(slug_val) .. '"'
      .. ' class="btn" target="_blank" rel="noopener">View live</a>')
    or  ""

  local tok = web.csrf_token()

  -- ── Content section: varies by kind ─────────────────────────────────
  -- blog/wiki: summary + tags fields + two-column markdown editor with
  --            live preview + image upload widget.
  -- docs:      MIME type selector + file upload input; no tags, no preview.
  local content_section_html, media_section_html
  media_section_html = ""
  if kind == "docs" then
    local mime_val = (item and item.mime_type ~= "" and item.mime_type) or "application/pdf"
    local mime_opts = ""
    for _, m in ipairs({
      "application/pdf", "application/epub+zip", "text/plain", "application/zip",
      "image/png", "image/jpeg", "image/gif", "image/webp",
      "application/octet-stream",
    }) do
      local sel = (m == mime_val) and " selected" or ""
      mime_opts = mime_opts
        .. '<option value="' .. m .. '"' .. sel .. '>'
        .. (media.MIME_LABELS[m] or m) .. "</option>"
    end
    local file_note = (item and item.mime_type ~= "")
      and ("Current file type: " .. EscapeHtml(item.mime_type) .. ".  Upload a new file to replace it.")
      or  "No file stored yet."
    content_section_html =
      '<div class="form-group">'
      .. '<label for="ed-mime">Document type</label>'
      .. '<select id="ed-mime" name="mime_type" class="select-input">'
      .. mime_opts .. '</select>'
      .. '</div>'
      .. '<div class="form-group">'
      .. '<label for="ed-file">File</label>'
      .. '<p class="field-note">' .. file_note .. '</p>'
      .. '<input type="file" id="ed-file" name="file">'
      .. '</div>'
  else
    content_section_html =
      -- Summary (used by feed cards and the Atom feed)
      '<div class="form-group">'
      .. '<label for="ed-summary">Summary</label>'
      .. '<input type="text" id="ed-summary" name="summary"'
      .. '  value="' .. EscapeHtml(summary_val) .. '"'
      .. '  placeholder="One-sentence summary shown on the feed and in the Atom feed"'
      .. '  autocomplete="off">'
      .. '</div>'
      -- Tags field (full-width)
      .. '<div class="form-group">'
      .. '<label for="ed-tags">Tags</label>'
      .. '<input type="text" id="ed-tags" name="tags"'
      .. '  value="' .. EscapeHtml(tags_val) .. '"'
      .. '  placeholder="comma, separated, tags" autocomplete="off">'
      .. '</div>'
      -- Two-column editor / preview
      .. '<div class="editor-layout">'
      .. '<div class="editor-pane">'
      .. '<div class="pane-label">Markdown</div>'
      -- hx-swap must be explicit: the inherited main-level swap is
      -- outerHTML, which would destroy #preview-pane on first preview.
      .. '<textarea id="ed-body" name="body" class="editor-textarea"'
      .. '  hx-post="/edit/preview"'
      .. '  hx-trigger="keyup changed delay:400ms"'
      .. '  hx-target="#preview-pane"'
      .. '  hx-swap="innerHTML"'
      .. '  hx-include="[name=csrf_token]"'
      .. '  placeholder="Write your content in Markdown\226\128\166">'
      .. EscapeHtml(body_val)
      .. '</textarea>'
      .. '</div>'
      .. '<div class="preview-col">'
      .. '<div class="pane-label">Preview</div>'
      .. '<div id="preview-pane" class="preview-pane post-body">'
      .. preview_html
      .. '</div>'
      .. '</div>'
      .. '</div>'  -- /editor-layout

    -- Image upload widget: its own form (forms cannot nest), posts
    -- multipart to /edit/upload; the response offers an insert button.
    media_section_html =
      '<div class="editor-media">'
      .. '<div class="pane-label">Insert image</div>'
      .. '<form hx-post="/edit/upload"'
      .. '  hx-encoding="multipart/form-data"'
      .. '  hx-target="#upload-result"'
      .. '  hx-swap="innerHTML"'
      .. '  class="upload-form">'
      .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'
      .. '<input type="file" name="file" accept="image/png,image/jpeg,image/gif,image/webp">'
      .. '<input type="text" name="name" placeholder="optional-slug" class="slug-input upload-name">'
      .. '<button type="submit" class="btn">Upload</button>'
      .. '</form>'
      .. '<div id="upload-result"></div>'
      .. '</div>'
  end

  -- The docs form uploads files; keep it a plain full-page submit
  -- rather than relying on boosted multipart handling.
  local enctype = (kind == "docs")
    and ' enctype="multipart/form-data" hx-boost="false"' or ""

  local body =
    '<div class="editor-wrap">'

    -- Header
    .. '<header class="post-header">'
    .. '<a href="/edit" class="back-link">&#8592; Dashboard</a>'
    .. '<h1>' .. EscapeHtml(page_title) .. '</h1>'
    .. '</header>'

    .. err_html

    -- Form
    .. '<form method="post" action="' .. action .. '"' .. enctype .. '>'
    .. '<input type="hidden" name="kind" value="' .. EscapeHtml(kind) .. '">'
    .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'

    -- Meta row: title / slug / published
    .. '<div class="editor-meta-row">'

    .. '<div class="form-group">'
    .. '<label for="ed-title">Title</label>'
    .. '<input type="text" id="ed-title" name="title"'
    .. '  value="' .. EscapeHtml(title_val) .. '"'
    .. '  placeholder="Post title" autocomplete="off">'
    .. '</div>'

    .. '<div class="form-group">'
    .. '<label for="ed-slug">Slug</label>'
    .. '<input type="text" id="ed-slug" name="slug"'
    .. '  value="' .. EscapeHtml(slug_val) .. '"'
    .. '  placeholder="url-friendly-slug" autocomplete="off" class="slug-input">'
    .. '</div>'

    .. '<div class="form-group-inline">'
    .. '<label class="checkbox-label">'
    .. '<input type="checkbox" name="published" value="1"' .. pub_checked .. '>'
    .. ' Published'
    .. '</label>'
    .. '</div>'

    .. '</div>'  -- /editor-meta-row

    .. content_section_html

    -- Actions
    .. '<div class="editor-actions">'
    .. view_link
    .. '<button type="submit" class="btn btn-primary">'
    .. (is_new and "Create" or "Save changes")
    .. '</button>'
    .. '</div>'

    .. '</form>'

    .. media_section_html

    -- Slug auto-derive + snippet insertion (runs once on DOMContentLoaded).
    .. '<script>(function(){'
    .. 'var t=document.getElementById("ed-title");'
    .. 'var s=document.getElementById("ed-slug");'
    .. 'if(t&&s){'
    .. 'var manual=s.value.length>0;'
    .. 't.addEventListener("input",function(){'
    ..   'if(manual)return;'
    ..   's.value=this.value.toLowerCase()'
    ..     '.replace(/[^a-z0-9]+/g,"-")'
    ..     '.replace(/^-+|-+$/g,"");'
    .. '});'
    .. 's.addEventListener("input",function(){manual=true;});'
    .. '}'
    .. 'window.insertSnippet=function(text){'
    ..   'var b=document.getElementById("ed-body");'
    ..   'if(!b)return;'
    ..   'var p=b.selectionStart||0;'
    ..   'b.value=b.value.slice(0,p)+text+b.value.slice(b.selectionEnd||p);'
    ..   'b.selectionStart=b.selectionEnd=p+text.length;'
    ..   'b.focus();'
    ..   'b.dispatchEvent(new Event("keyup"));'
    .. '};'
    .. '})();</script>'

    .. '</div>'  -- /editor-wrap

  return render.respond(page_title, body)
end

-- ── GET /edit — admin dashboard ───────────────────────────────────────
route(fm.GET "/edit", function(r)
  local denied = auth.require_session()
  if denied then return denied end

  local tok  = web.csrf_token()
  local all  = db.list_all()
  local rows = {}
  for _, item in ipairs(all) do
    local date = web.fmt_date(item.created_at)
    local pub_badge = item.published == 1
      and '<span class="status-badge status-published">Published</span>'
      or  '<span class="status-badge status-draft">Draft</span>'
    local kind_badge =
      '<span class="kind-badge kind-' .. item.kind .. '">' .. item.kind .. '</span>'
    rows[#rows + 1] =
      '<tr>'
      .. '<td>' .. kind_badge .. '</td>'
      .. '<td><a href="/edit/' .. item.id .. '">' .. EscapeHtml(item.title) .. '</a></td>'
      .. '<td class="col-mono">' .. EscapeHtml(item.slug) .. '</td>'
      .. '<td>' .. pub_badge .. '</td>'
      .. '<td class="col-mono">' .. date .. '</td>'
      .. '<td class="col-actions">'
      ..   '<a href="/edit/' .. item.id .. '" class="action-link">Edit</a>'
      -- No explicit hx-post: the form is boosted via the main-level
      -- hx-boost, so the redirect response swaps #content correctly;
      -- hx-confirm still guards the boosted submit.
      ..   '<form method="post" action="/edit/' .. item.id .. '/delete"'
      ..        ' hx-confirm="Delete this post?"'
      ..        ' class="action-delete-form">'
      ..     '<input type="hidden" name="csrf_token" value="' .. tok .. '">'
      ..     '<button type="submit" class="action-link action-link-danger">Delete</button>'
      ..   '</form>'
      .. '</td>'
      .. '</tr>'
  end

  local table_html = #rows == 0
    and '<div class="no-results">No content yet. Use the buttons above to create your first post.</div>'
    or  '<div class="admin-table-wrap">'
        .. '<table class="admin-table">'
        .. '<thead><tr>'
        .. '<th>Kind</th><th>Title</th><th>Slug</th>'
        .. '<th>Status</th><th>Created</th><th>Actions</th>'
        .. '</tr></thead>'
        .. '<tbody>' .. table.concat(rows, "\n") .. '</tbody>'
        .. '</table>'
        .. '</div>'

  local new_buttons = '<a href="/edit/new?kind=blog" class="btn btn-primary">+ Blog post</a>'
  if config.enabled("feature_wiki") then
    new_buttons = new_buttons
      .. '<a href="/edit/new?kind=wiki" class="btn btn-primary">+ Wiki page</a>'
  end
  new_buttons = new_buttons
    .. '<a href="/edit/new?kind=docs" class="btn btn-primary">+ File</a>'
    .. '<a href="/edit/links" class="btn">Links page</a>'
    .. '<a href="/edit/settings" class="btn">Settings</a>'

  local body =
    '<div class="section-header admin-section-header">'
    .. '<h1>Dashboard</h1>'
    .. '<form method="post" action="/logout" class="logout-form">'
    .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'
    .. '<button type="submit" class="btn btn-logout">SIGN_OUT</button>'
    .. '</form>'
    .. '</div>'
    .. '<div class="admin-new-row">' .. new_buttons .. '</div>'
    .. table_html

  return render.respond("Dashboard", body)
end)

-- ── Settings page (must be registered before /edit/:id) ──────────────

local SETTINGS_FIELDS = {
  { key = "site_title",     label = "Site title" },
  { key = "site_tagline",   label = "Tagline (shown above the feed)" },
  { key = "site_author",    label = "Author name (footer, Atom feed)" },
  { key = "base_url",       label = "Base URL (absolute, no trailing slash — required for the Atom feed)" },
  { key = "posts_per_page", label = "Posts per page on the feed" },
}

local function text_field(key, label, placeholder)
  return '<div class="form-group">'
    .. '<label for="set-' .. key .. '">' .. EscapeHtml(label) .. '</label>'
    .. '<input type="text" id="set-' .. key .. '" name="' .. key .. '"'
    .. '  value="' .. EscapeHtml(config.get(key)) .. '"'
    .. '  placeholder="' .. EscapeHtml(placeholder or config.DEFAULTS[key] or "") .. '"'
    .. '  autocomplete="off">'
    .. '</div>'
end

local function checkbox_field(key, label)
  local checked = config.enabled(key) and " checked" or ""
  return '<div class="form-group-inline">'
    .. '<label class="checkbox-label">'
    .. '<input type="checkbox" name="' .. key .. '" value="1"' .. checked .. '>'
    .. ' ' .. EscapeHtml(label)
    .. '</label>'
    .. '</div>'
end

local function settings_page(msg)
  local tok = web.csrf_token()

  local site_fields = {}
  for _, f in ipairs(SETTINGS_FIELDS) do
    site_fields[#site_fields + 1] = text_field(f.key, f.label)
  end

  local nav_fields = {}
  for n = 1, 4 do
    nav_fields[#nav_fields + 1] =
      '<div class="nav-link-row">'
      .. text_field("nav_link" .. n .. "_label", "Link " .. n .. " label", "Label")
      .. text_field("nav_link" .. n .. "_url", "Link " .. n .. " URL", "https://\226\128\166 or /path")
      .. '</div>'
  end

  local msg_html = msg
    and '<div class="settings-saved"><p>' .. EscapeHtml(msg) .. '</p></div>'
    or ""

  local body =
    '<div class="settings-wrap">'
    .. '<header class="post-header">'
    .. '<a href="/edit" class="back-link">&#8592; Dashboard</a>'
    .. '<h1>Settings</h1>'
    .. '</header>'
    .. msg_html
    .. '<form method="post" action="/edit/settings">'
    .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'

    .. '<h2 class="settings-section-label">Site</h2>'
    .. table.concat(site_fields)
    .. checkbox_field("feature_wiki", "Enable the wiki section")

    .. '<h2 class="settings-section-label">Navbar links</h2>'
    .. '<p class="field-note">Up to four extra nav items. Both label and URL must be set for a link to appear.</p>'
    .. table.concat(nav_fields)

    .. '<h2 class="settings-section-label">Radio player</h2>'
    .. checkbox_field("radio_enabled", "Show the floating radio player")
    .. text_field("radio_url", "Playlist URL (m3u)", "https://radio.example.com/stations.m3u")

    .. '<div class="editor-actions">'
    .. '<button type="submit" class="btn btn-primary">Save settings</button>'
    .. '</div>'
    .. '</form>'
    .. '</div>'

  return render.respond("Settings", body)
end

route(fm.GET "/edit/settings", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  return settings_page(nil)
end)

route(fm.POST "/edit/settings", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then return forbidden() end

  for _, f in ipairs(SETTINGS_FIELDS) do
    local v = web.trim(r.params[f.key] or "")
    if f.key == "posts_per_page" and v ~= "" then
      local n = tonumber(v)
      v = (n and n >= 1 and n <= 100) and tostring(math.floor(n)) or ""
    end
    if f.key == "base_url" then
      v = v:gsub("/+$", "")
    end
    config.set(f.key, v)
  end

  -- Nav links: label free-form; URL must be absolute http(s) or site-relative.
  for n = 1, 4 do
    config.set("nav_link" .. n .. "_label", web.trim(r.params["nav_link" .. n .. "_label"]))
    local u = web.trim(r.params["nav_link" .. n .. "_url"])
    if u ~= "" and not (u:match("^https?://") or u:match("^/")) then u = "" end
    config.set("nav_link" .. n .. "_url", u)
  end

  local radio_url = web.trim(r.params.radio_url)
  if radio_url ~= "" and not radio_url:match("^https?://") then radio_url = "" end
  config.set("radio_url", radio_url)

  config.set("feature_wiki",  r.params.feature_wiki  == "1" and "1" or "0")
  config.set("radio_enabled", r.params.radio_enabled == "1" and "1" or "0")

  return settings_page("Settings saved.")
end)

-- ── /edit/links — editor for the single free-form Links page ─────────
-- (Registered before /edit/:id so "links" is not parsed as an id.)

local function links_editor_page(msg)
  local tok      = web.csrf_token()
  local body_val = config.get("links_page")
  local preview_html = body_val ~= ""
    and md.render(body_val)
    or  '<p class="text-muted">Preview will appear here\226\128\166</p>'
  local msg_html = msg
    and '<div class="settings-saved"><p>' .. EscapeHtml(msg) .. '</p></div>'
    or ""

  local body =
    '<div class="editor-wrap">'
    .. '<header class="post-header">'
    .. '<a href="/edit" class="back-link">&#8592; Dashboard</a>'
    .. '<h1>Links page</h1>'
    .. '</header>'
    .. '<p class="field-note">A single free-form Markdown page served at /links.'
    .. ' Leave it empty to remove the page and its nav item.</p>'
    .. msg_html
    .. '<form method="post" action="/edit/links">'
    .. '<input type="hidden" name="csrf_token" value="' .. tok .. '">'
    .. '<div class="editor-layout">'
    .. '<div class="editor-pane">'
    .. '<div class="pane-label">Markdown</div>'
    .. '<textarea id="ed-body" name="body" class="editor-textarea"'
    .. '  hx-post="/edit/preview"'
    .. '  hx-trigger="keyup changed delay:400ms"'
    .. '  hx-target="#preview-pane"'
    .. '  hx-swap="innerHTML"'
    .. '  hx-include="[name=csrf_token]"'
    .. '  placeholder="## Friends\10- [somebody](https://example.com)\226\128\166">'
    .. EscapeHtml(body_val)
    .. '</textarea>'
    .. '</div>'
    .. '<div class="preview-col">'
    .. '<div class="pane-label">Preview</div>'
    .. '<div id="preview-pane" class="preview-pane post-body">'
    .. preview_html
    .. '</div>'
    .. '</div>'
    .. '</div>'
    .. '<div class="editor-actions">'
    .. (body_val ~= ""
        and '<a href="/links" class="btn" target="_blank" rel="noopener">View live</a>'
        or "")
    .. '<button type="submit" class="btn btn-primary">Save</button>'
    .. '</div>'
    .. '</form>'
    .. '</div>'

  return render.respond("Links page", body)
end

route(fm.GET "/edit/links", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  return links_editor_page(nil)
end)

route(fm.POST "/edit/links", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then return forbidden() end

  config.set("links_page", r.params.body or "")
  return links_editor_page("Saved.")
end)

-- ── GET /edit/new?kind=:kind ──────────────────────────────────────────
route(fm.GET "/edit/new", function(r)
  local denied = auth.require_session()
  if denied then return denied end

  local kind = r.params.kind
  if kind ~= "blog" and kind ~= "wiki" and kind ~= "docs" then kind = "blog" end

  return editor_page(nil, kind, nil)
end)

-- ── POST /edit/new ────────────────────────────────────────────────────
route(fm.POST "/edit/new", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then return forbidden() end

  local kind    = r.params.kind or "blog"
  local title   = web.trim(r.params.title)
  local slug    = web.trim(r.params.slug)
  local body    = r.params.body or ""
  local tags    = web.trim(r.params.tags)
  local summary = web.trim(r.params.summary)
  local pub     = (r.params.published == "1") and 1 or 0

  if kind ~= "blog" and kind ~= "wiki" and kind ~= "docs" then kind = "blog" end
  if slug == "" then slug = web.slugify(title) end

  if title == "" then
    return editor_page(nil, kind, "Title is required.")
  end
  if not web.valid_slug(slug) then
    return editor_page(nil, kind,
      "Slug must contain only lowercase letters, digits, and hyphens (no leading or trailing hyphens).")
  end

  local ok, err
  if kind == "docs" then
    local file_data = r.params.file or ""
    local mime_type = r.params.mime_type or "application/pdf"
    if file_data == "" then
      return editor_page(nil, kind, "A file is required.")
    end
    ok, err = pcall(db.insert_doc, slug, title, mime_type, file_data, pub)
  else
    if body:match("^%s*$") then
      return editor_page(nil, kind, "Body cannot be empty.")
    end
    ok, err = pcall(db.insert_content, kind, slug, title, body, summary, pub, tags)
  end

  if not ok then
    local msg = tostring(err):find("UNIQUE")
      and "A post with that slug already exists for this section."
      or  "Database error: " .. tostring(err)
    return editor_page(nil, kind, msg)
  end

  return web.redirect("/" .. kind .. "/" .. slug)
end)

-- ── POST /edit/preview ────────────────────────────────────────────────
route(fm.POST "/edit/preview", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then
    return render.partial('<p class="text-muted">Invalid request token.</p>')
  end

  local body = r.params.body or ""
  if body:match("^%s*$") then
    return render.partial('<p class="text-muted">Preview will appear here\226\128\166</p>')
  end
  return render.partial(md.render(body))
end)

-- ── POST /edit/upload — image upload from the editor ─────────────────
route(fm.POST "/edit/upload", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then
    return render.partial('<p class="upload-error">Invalid request token.</p>')
  end

  local data = r.params.file or ""
  if data == "" then
    return render.partial('<p class="upload-error">No file selected.</p>')
  end

  local mime = media.sniff(data)
  if not mime or not media.is_image(mime) then
    return render.partial(
      '<p class="upload-error">Unsupported file type. Use PNG, JPEG, GIF, or WebP.</p>')
  end

  local slug = web.slugify(web.trim(r.params.name))
  if slug == "" then
    slug = "img-" .. os.date("!%Y%m%d-%H%M%S")
  end

  -- Retry with a random suffix on slug collision.
  local ok, err = pcall(db.insert_doc, slug, slug, mime, data, 1)
  if not ok and tostring(err):find("UNIQUE") then
    slug = slug .. "-" .. web.random_hex(3)
    ok, err = pcall(db.insert_doc, slug, slug, mime, data, 1)
  end
  if not ok then
    Log(kLogWarn, "upload failed: " .. tostring(err))
    return render.partial('<p class="upload-error">Upload failed. Check the server log.</p>')
  end

  local snippet = "![](/docs/" .. slug .. ")"
  return render.partial(
    '<div class="upload-ok">'
    .. '<code>' .. EscapeHtml(snippet) .. '</code>'
    .. '<button type="button" class="btn"'
    .. " onclick=\"insertSnippet(this.dataset.snippet)\""
    .. ' data-snippet="' .. EscapeHtml(snippet) .. '">Insert into post</button>'
    .. '</div>')
end)

-- ── GET /edit/:id ─────────────────────────────────────────────────────
route(fm.GET "/edit/:id", function(r)
  local denied = auth.require_session()
  if denied then return denied end

  local id = tonumber(r.params.id)
  if not id then return web.not_found() end

  local item = db.get_by_id(id)
  if not item then return web.not_found() end

  return editor_page(item, item.kind, nil)
end)

-- ── POST /edit/:id ────────────────────────────────────────────────────
route(fm.POST "/edit/:id", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then return forbidden() end

  local id = tonumber(r.params.id)
  if not id then return web.not_found() end

  local item = db.get_by_id(id)
  if not item then return web.not_found() end

  local title = web.trim(r.params.title)
  local slug  = web.trim(r.params.slug)
  local pub   = (r.params.published == "1") and 1 or 0

  if title == "" then
    return editor_page(item, item.kind, "Title is required.")
  end
  if not web.valid_slug(slug) then
    return editor_page(item, item.kind,
      "Slug must contain only lowercase letters, digits, and hyphens.")
  end

  local ok, err
  if item.kind == "docs" then
    local file_data = r.params.file or ""
    local mime_type = r.params.mime_type or ""
    local fields = { title = title, slug = slug, published = pub }
    -- Only update file if a new one was uploaded; keep existing blob otherwise.
    if file_data ~= "" then fields.file_data = file_data end
    if mime_type ~= "" then fields.mime_type = mime_type end
    ok, err = pcall(db.update_content, id, fields)
  else
    local body    = r.params.body or ""
    local tags    = web.trim(r.params.tags)
    local summary = web.trim(r.params.summary)
    if body:match("^%s*$") then
      return editor_page(item, item.kind, "Body cannot be empty.")
    end
    ok, err = pcall(db.update_content, id,
      { title = title, slug = slug, body = body, tags = tags,
        summary = summary, published = pub })
  end

  if not ok then
    local msg = tostring(err):find("UNIQUE")
      and "A post with that slug already exists for this section."
      or  "Database error: " .. tostring(err)
    return editor_page(item, item.kind, msg)
  end

  return web.redirect("/" .. item.kind .. "/" .. slug)
end)

-- ── POST /edit/:id/delete ─────────────────────────────────────────────
route(fm.POST "/edit/:id/delete", function(r)
  local denied = auth.require_session()
  if denied then return denied end
  if not web.csrf_check(r) then return forbidden() end

  local id = tonumber(r.params.id)
  if id then
    local ok, err = pcall(db.delete_content, id)
    if not ok then Log(kLogWarn, "delete failed: " .. tostring(err)) end
  end

  return web.redirect("/edit")
end)