-- app state + messages

-- screens
scr_boot=0
scr_timeline=1
scr_thread=2
scr_compose=3
scr_auth=4
scr_demo=5
scr_splash=6

scr=scr_splash
scr_wt=-1       -- time() a screen change started its slide (-1 = none yet)
lastscr=-1      -- last scr seen, for edge-detecting screen changes
trans_dir=1          -- 1=forward (cards from right), -1=back (cards from left)
prev_was_thread=false  -- title to roll out on next transition
prev_was_compose=false -- true when closing the compose drawer
feed={}        -- timeline posts
thread={}      -- open thread posts
posts=feed     -- active list pointer
sel=1
scroll=0
prev_sel=1
prev_scroll=0
just_switched=false
discard_loading=false -- true while discarding an in-flight REQ_MORE after screen change
thread_focus=0        -- refid to auto-focus after a thread loads (0 = none)
loading=true
hasmore=false
status="connecting to bluesky..."
status_t=0
stik=0

-- compose state
draft=""
reply_to=0     -- 0 = new post, else refid
quote_of=0     -- 0 = not a quote, else the quoted post's refid
quote_name=""  -- display name of the quoted post's author (compose header)
maxchars=300

theme=0 -- 0=day,1=night
last_pt=-1 -- last page-theme bit seen on pin 126 (edge-detect)
mi_track=-1 mi_theme=-1 -- last track/theme reflected in the pause menu labels
-- feed switcher: names from js (idx 1=following). active_feed is the picked
-- index; loaded_feed is what the timeline currently shows (reload when they
-- differ); mi_feed shadows the pause-menu label registration.
feeds={"following"} feedsm={"following"} active_feed=1 loaded_feed=1 mi_feed=-1
alt_ref=0  -- refid whose alt-text marquee clock is running
alt_t0=0   -- time() the active post's alt marquee started

function set_status(s)
 status=s
 status_t=time()
end

function parse_post(s)
 local f=split(s,"\1",false)
 return {
  name=f[1] or "?",
  handle=f[2] or "",
  reltime=f[3] or "",
  text=f[4] or "",
  likes=f[5] or "0",
  reposts=f[6] or "0",
  replies=f[7] or "0",
  refid=tonum(f[8]) or 0,
  depth=tonum(f[9]) or 0,
  -- img_state: 0=no image, 1=loading, 2=ready
  img_state=(tonum(f[10]) or 0)==1 and 1 or 0,
  linktext=f[11] or "",
  liked=(tonum(f[12]) or 0)==1, -- viewer already liked this post?
  alt=f[13] or "", -- image alt text (marquee'd when long + selected)
  reposted=(tonum(f[14]) or 0)==1, -- viewer already reposted this post?
  avatar_pixels=nil,
 }
end

-- run fn(p) on every post matching id across the timeline + open thread - the
-- same id can exist in both when uriRefs reuses a timeline id in a thread post.
function eachpost(id,fn)
 for l in all({feed,thread}) do
  for p in all(l) do
   if p.refid==id then fn(p) end
  end
 end
end

-- unpack 2px/byte nibble-packed bytes (hi nibble first) into a 0-15 pixel list
function unpack_px(packed)
 local px={}
 for b in all(packed) do add(px,(b>>4)&0xf) add(px,b&0xf) end
 return px
end

-- update all posts with this refid (image/avatar can land in feed + thread both);
-- px is unpacked once on first match, then shared via the closure upvalue.
function on_image(refid,packed)
 local px
 eachpost(refid,function(p)
  px=px or unpack_px(packed)
  p.pixels=px p.img_state=2
 end)
end

function on_image_fail(refid)
 eachpost(refid,function(p) p.img_state=0 end)
end

function on_avatar(refid,packed)
 local px
 eachpost(refid,function(p)
  px=px or unpack_px(packed)
  p.avatar_pixels=px
 end)
end

function on_message(op,arg,s)
 if op==op_demo_stop then exit_demo() return end
 if not ONLINE then return end
 if op==op_resp_post then
  if not discard_loading then
   add(posts,parse_post(s))
   loading=false
  end
  elseif op==op_resp_end then
   if discard_loading then
    discard_loading=false -- REQ_MORE fully discarded; next response is REQ_THREAD
   else
    loading=false
    hasmore=(arg!=0)
    if #posts>0 then sfx(8) end -- new-posts chime
    -- auto-focus a specific post after a thread loads (e.g. self-reply from timeline)
    if scr==scr_thread and thread_focus>0 then
     for i=1,#thread do
      if thread[i].refid==thread_focus then
       sel=i scroll=max(0,i-2)
       break
      end
     end
     thread_focus=0
    end
   end
  elseif op==op_resp_ok then
   set_status"posted!"
   reset_draft()
   sfx(6) -- success
   open_timeline(true)
  elseif op==op_resp_error then
   loading=false
   set_status(sub(s,1,40))
   sfx(7) -- error
   -- a failed send leaves the draft intact: drop back into compose so it can
   -- be edited and resent (a fetch error has no draft, so this is a no-op).
   if #draft>0 then
    scr=scr_compose
    poke(0x5f2d,1)
   end
 elseif op==op_resp_feeds then
  -- rebuild the feed switcher from js: names arrive interleaved [header,menu,...].
  -- keep active/loaded in range and equal so arriving feeds never trigger a
  -- spurious reload; mi_feed=-1 forces re-register.
  local a=split(s,"\1",false) feeds={} feedsm={}
  for i=1,#a,2 do add(feeds,a[i]) add(feedsm,a[i+1]) end
  active_feed=mid(1,active_feed,#feeds) loaded_feed=active_feed mi_feed=-1
 elseif op==op_resp_auth_lost then
  scr=scr_auth
 end
end