let writer accum data =
	Buffer.add_string accum data;
	String.length data

let showContent content =
	Printf.printf "%s" (Buffer.contents content);
	flush stdout

let showInfo connection =
	Printf.printf "Time: %f for: %s\n"
		(Curl.get_totaltime connection)
		(Curl.get_effectiveurl connection)

let getContent connection url =
	Curl.set_url connection url;
	Curl.perform connection

let curl_pull url =
	let result = Buffer.create 4069
	and errorBuffer = ref "" in
	let connection = Curl.init () in
	try
		Curl.set_errorbuffer connection errorBuffer;
		Curl.set_writefunction connection (writer result);
		Curl.set_followlocation connection true;
		Curl.set_url connection url;
		Curl.perform connection;
(*		showContent result;*)
(*		showInfo connection;*)
		Curl.cleanup connection;
		Ok result
	with
	| Curl.CurlException (_reason, _code, _str) ->
		Curl.cleanup connection;
		Error (Printf.sprintf "Error: %s %s" url !errorBuffer)
	| Failure s ->
		Curl.cleanup connection;
		Error (Printf.sprintf "Caught exception: %s" s)

let newer time id dir =
	match Logarion.File_store.to_text @@ Filename.(concat dir (Logarion.Id.short id) ^ ".txt") with
	| Error x -> prerr_endline x; true
	| Ok txt -> time > (Logarion.(Header_pack.date (Date.listing txt.date)))
	| exception (Sys_error _) -> true

let print_peers p =
	let open Logarion.Header_pack in
	match Msgpck.to_list p.peers with [] -> ()
	| ps -> print_endline @@
		List.fold_left (fun a x -> Printf.sprintf "%s %s" a (Msgpck.to_string x)) "peers: " ps

let parse_index _is_selected fn url dir p =
	let open Logarion.Header_pack in
	match Msgpck.to_list p.texts with
	| [] -> Printf.printf "%s => %s, has empty index\n" p.info.title dir; false
	| texts ->
		let numof_texts = string_of_int @@ List.length texts in
		let text_num_len = String.length numof_texts in
		Printf.printf "%*d/%s %s => %s\r" text_num_len 0 numof_texts p.info.title dir;
		let of_pck i x =
			Printf.printf "\r%*d/%s %!" text_num_len (i+1) numof_texts;
			match x with
			| Msgpck.List (id::time::title::_authors::_topics) ->
				(match Logarion.Header_pack.to_id id with
				| "" -> Printf.eprintf "Invalid id for%s " (Msgpck.to_string title)
				| id ->
					let t = match time with Msgpck.Int i -> Int32.of_int i | Msgpck.Uint32 i -> i | x -> Msgpck.to_uint32 x in
					if newer t id dir then fn url dir id)
			| _ -> prerr_endline ("Invalid record structure") in
		List.iteri of_pck texts;
		print_newline ();
		true

let fname dir text = Filename.concat dir (Logarion.Text.short_id text ^ ".txt")
let pull_text url dir id =
	let u = Filename.concat url ((Logarion.Id.short id) ^ ".txt") in
	match curl_pull u with
	| Error msg -> Printf.eprintf "Failed getting %s: %s" u msg
	| Ok txt ->
		let txt = Buffer.contents txt in
		match Logarion.Text.of_string txt with
		| Error s -> prerr_endline s
		| Ok text ->
			let file = open_out_gen [Open_creat; Open_trunc; Open_wronly] 0o640 (fname dir text) in
			output_string file txt; close_out file

let pull_index url _authors _topics =
	let index_url = url ^ "/index.pck" in
	match curl_pull index_url with
	| Error s -> prerr_endline s; false
	| Ok body ->
		match Logarion.Header_pack.of_string (Buffer.contents body) with
		| Error s -> Printf.printf "Error with %s: %s\n" url s; false
		| Ok pk ->
			let dir = Filename.concat Logarion.Peers.text_dir pk.info.id in
			Logarion.File_store.with_dir dir;
			let file = open_out_gen [Open_creat; Open_trunc; Open_wronly] 0o640 (Filename.concat dir "index.pck") in
			output_string file ( Logarion.Header_pack.string {
					pk with info = { pk.info with locations = url::pk.info.locations }});
			close_out file;
(*			let predicates = A.predicate A.authored authors_opt*)
(*				@ A.predicate A.topics topics_opt in*)
			let is_selected text = List.fold_left (fun a e -> a && e text) true [](*predicates*) in
			try parse_index is_selected pull_text url dir pk with
			Invalid_argument msg -> Printf.eprintf "Failed to parse: %s\n%!" msg; false

let pull_list auths topics =
	Curl.global_init Curl.CURLINIT_GLOBALALL;
	let pull got_one peer_url = if got_one then got_one else
		(pull_index peer_url auths topics) in
	Logarion.Peers.fold pull false;
	Curl.global_cleanup ()

let pull url auths topics = match url with
	| "" -> pull_list auths topics | x -> ignore (pull_index x auths topics)

open Cmdliner
let term =
	let authors = Arg.(value & opt (some string) None & info ["a"; "authors"]
		~docv:"comma-separated names" ~doc:"filter by authors") in
	let topics = Arg.(value & opt (some string) None & info ["t"; "topics"]
		~docv:"comma-separated topics" ~doc:"filter by topics") in
	let url = Arg.(value & pos 0 string "" & info [] ~docv:"URL"
		~doc:"Repository location") in
	Term.(const pull $ url $ authors $ topics),
		Term.info "pull" ~doc:"pull listed texts" ~man:[ `S "DESCRIPTION";
			`P "Pull texts from known repositories. To add a new repository use:";
			`P "txt pull [url]";
			`P ("This creates a directory in " ^ Logarion.Peers.text_dir
				^ " and downloads the text index.pck file in it")]

(*module Msg = struct*)
(*	type t = string * string*)
(*	let compare (x0,y0) (x1,y1) =*)
(*		match compare x1 x0 with 0 -> String.compare y0 y1 | c -> c*)
(*end*)
(*module MsgSet = Set.Make(Msg)*)
(*let pull_msgs url _authors _topics =*)
(*	match http_apply response url with*)
(*	| Error msg ->*)
(*		Printf.eprintf "Failed index request for %s %s" url msg*)
(*	| Ok body ->*)
(*		let rec fold_msgs s a fn =*)
(*			let t, msg = Scanf.bscanf s "%s %s@\n" (fun t m -> t, m) in*)
(*			if t <> "" then fold_msgs s (fn a t msg) fn else a*)
(*		in*)
(*		let s = Scanf.Scanning.from_string body in*)
(*		let msgs = MsgSet.empty in*)
(*		let date_string t = Ptime.to_date t |>*)
(*			fun (y, m, d) -> Printf.sprintf "%04d-%02d-%02d" y m d in*)
(*		let msgs = fold_msgs s msgs*)
(*			(fun msgs t m -> match Ptime.of_rfc3339 t with*)
(*			| Ok (v,_,_) -> let open MsgSet in*)
(*				let msgs = if cardinal msgs > 1 then remove (max_elt msgs) msgs else msgs in*)
(*				add (v,m) msgs*)
(*			| _ -> msgs) in*)
(*		let msg_string = MsgSet.fold*)
(*			(fun (t,m) a -> a ^ Printf.sprintf "  %s 𐄁 %s\n" (date_string t) m)*)
(*			msgs "" in*)
(*		Printf.printf "┌───{ %s }───┐\n%s" url msg_string*)