open Kosuzu

let is_older s d = try Unix.((stat d).st_mtime < (stat s).st_mtime) with _-> true

let convert cs r (text, files) = match Text.str "Content-Type" text with
	| "" | "text/plain" ->
		let source = List.hd files in
		let dest = Filename.concat r.Conversion.dir (Text.short_id text) in
		List.fold_left (fun a f ->
			match f.Conversion.page with None -> false || a
			| Some page ->
				let dest = dest ^ f.Conversion.ext in
				(if is_older source dest || Conversion.Rel.Id_map.mem text.Text.id r.relations
				 then (File_store.file dest (page r text); true) else false)
				|| a)
			false cs
	| x -> Printf.eprintf "Can't convert Content-Type: %s file: %s" x text.Text.title; false

let converters types kv =
	let n = String.split_on_char ',' types in
	let t = [] in
	let t = if List.(mem "all" n || mem "htm" n) then (Html.converter kv)::t else t in
	let t = if List.(mem "all" n || mem "atom" n) then (Atom.converter "text/html")::t else t in
	let t = if List.(mem "all" n || mem "gmi" n) then (Gemini.converter)::t else t in
	let t = if List.(mem "all" n || mem "gmi-atom" n) then (Atom.converter "text/gemini")::t else t in
	t

let directory converters noindex repo =
	let order = File_store.oldest in
	let repo =
		let open Conversion in
		let rels = File_store.fold ~dir:repo.dir ~order Rel.acc_txt Rel.empty_map in
		let relations = Peers.fold Rel.acc_pck rels in
		{ repo with relations } in
	let acc (ts,ls,acc) ((elt,_) as r) = Topic_set.to_map ts (Text.set "topics" elt), elt::ls,
		if convert converters repo r then acc+1 else acc in
	let topics, texts, count =
		File_store.fold ~dir:repo.Conversion.dir ~order acc (Topic_set.Map.empty, [], 0) in
	let topic_roots = try List.rev @@ String_set.list_of_csv (Store.KV.find "Topics" repo.kv)
		with Not_found -> Topic_set.roots topics in
	let repo = Conversion.{ repo with topic_roots; topics; texts = List.rev texts } in
	if not noindex then
		List.iter (fun c -> match c.Conversion.indices with None -> () | Some f -> f repo) converters;
	Printf.printf "Converted: %d Indexed: %d\n" count (List.length texts)

let load_kv dir =
	let kv = File_store.of_kv_file () in
	let idx = Filename.concat dir "index.pck" in
	if not (Sys.file_exists idx) then kv else
		match Header_pack.of_string @@ File_store.to_string (idx) with
		| Error s -> prerr_endline s; kv
		| Ok { info; peers; _ } ->
			let kv = if Store.KV.mem "Id" kv then kv else Store.KV.add "Id" info.Header_pack.id kv in
			let kv = if Store.KV.mem "Title" kv then kv else Store.KV.add "Title" info.Header_pack.title kv in
			let kv = if Store.KV.mem "Locations" kv then kv else Store.KV.add "Locations" (String.concat ";\n" info.Header_pack.locations) kv in
			let kv = Store.KV.add "Peers" (String.concat ";\n" Header_pack.(to_str_list peers)) kv in
			kv

let at_path types noindex path = match path with
	| "" -> prerr_endline "unspecified text file or directory"
	| path when Sys.file_exists path ->
		if Sys.is_directory path then (
			let kv = load_kv path in
			let repo = { (Conversion.empty ()) with dir = path; kv } in
			directory (converters types kv) noindex repo
		) else (
			match File_store.to_text path with
			| Error s -> prerr_endline s
			| Ok text ->
				let dir = "." in
				let open Conversion in
				let relations = File_store.(fold ~dir ~order:newest Rel.acc_txt Rel.empty_map) in
				let repo = { (Conversion.empty ()) with dir; kv = load_kv ""; relations } in
				ignore @@ convert (converters types repo.kv) repo (text, [path])
		)
	| path -> Printf.eprintf "Path doesn't exist: %s" path

open Cmdliner

let path = Arg.(value & pos 0 string "" & info [] ~docv:"path" ~doc:"Text file or directory to convert. If directory is provided, it must contain an index.pck (see: txt index)")
let types = Arg.(value & opt string "all" & info ["t"; "type"] ~docv:"output type" ~doc:"Convert to file type")
let noindex = Arg.(value & flag & info ["noindex"] ~doc:"Don't create indices in target format")

let convert_t = Term.(const at_path $ types $ noindex $ path)

let cmd =
  let doc = "Convert texts" in
  let man = [
      `S Manpage.s_description;
      `P "Convert text or indexed texts within a directory to another format.";
      `P "If path is a directory must contain an index.pck.";
      `P "Run `txt index` first." ]
  in
  let info = Cmd.info "convert" ~doc ~man in
  Cmd.v info convert_t