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

type filter_t = { authors: Logarion.Person.Set.t; topics: Logarion.String_set.t }

let print_pull_start width total title dir =
	Printf.printf "%*d/%s %s => %s %!" width 0 total title dir

let print_pull width total i =
	Printf.printf "\r%*d/%s %!" width (i+1) total

let printers total title dir =
	let width = String.length total in
	print_pull_start width total title dir;
	print_pull width total

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 per_text url dir filter print i id time title authors topics = match id with
	| "" -> Printf.eprintf "\nInvalid id for %s\n" title
	| id -> let open Logarion in
		print i;
		if newer time id dir
		&& (String_set.empty = filter.topics
			|| String_set.exists (fun t -> List.mem t topics) filter.topics)
		&& (Person.Set.empty = filter.authors
			|| Person.Set.exists (fun t -> List.mem (Person.to_string t) authors) filter.authors)
		then pull_text url dir id

(*TODO: integrate in lib*)
let validate_id_length s = String.length s <= 32
let validate_id_chars s = try
	String.iter (function 'a'..'z'|'A'..'Z'|'0'..'9'-> () | _ -> raise (Invalid_argument "")) s;
	true
	with Invalid_argument _ -> false

let pull_index url authors_opt topics_opt =
	let index_url = Filename.concat 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 when pk.info.id = "" ->
			Printf.printf "Empty ID index.pck, skipping %s\n" url; false
		| Ok pk when not (validate_id_length pk.info.id) ->
			Printf.printf "Index pack ID longer than 32 characters, skipping %s\n" url; false
		| Ok pk when not (validate_id_chars pk.info.id) ->
			Printf.printf "Index pack contains invalid ID characters, skipping %s\n" url; 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 filter = let open Logarion in {
				authors = (match authors_opt with Some s -> Person.Set.of_string s | None -> Person.Set.empty);
				topics =( match topics_opt with Some s -> String_set.of_string s | None -> String_set.empty);
			} in
			let name = match pk.info.title with "" -> url | title -> title in
			let print = printers (string_of_int @@ Logarion.Header_pack.numof_texts pk) name dir in
			try Logarion.Header_pack.iteri (per_text url dir filter print) pk; print_newline (); true
			with Invalid_argument msg -> Printf.printf "\nFailed to parse %s: %s\n%!" url 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
	let fold_locations init peer =
		ignore @@ List.fold_left pull init peer.Logarion.Peers.locations;
		false
	in
	ignore @@ Logarion.Peers.fold fold_locations 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*)