(: Store for XQuery document data , type, text,uri
 on save parse is created and stored
 implementation: data is stored in webSocket
@author Andy Bunce
:)
module namespace docs="lsp/docs";
import module namespace p="xq4" at "xq4.xqm";

declare record docs:Position(
	 (: Line position in a document (zero-based). :)
	line as xs:integer,

	(: Character offset on a line in a document (zero-based). :)
	character as xs:integer
);

(: document info :)
declare type docs:property as enum(
    "textDocument",
    "parse"
);

(: get $property for $file from session $socket :)
declare function docs:get(
    $socket as xs:string,
    $file as xs:string,
    $property as docs:property
)
{
    let $key:=ws:get($socket,"files")($file)($property)
    return ws:get($socket,$key)
};

(: save $textDocument data as session $socket properties :)
declare function docs:save(
    $socket as xs:string,
    $textDocument as map(*)
)
{
let $text as xs:string:=$textDocument?text
let $uri:=$textDocument?uri
let $files:=ws:get($socket,"files",{})
let $files:=if(map:contains($files,$uri)) 
            then $files 
            else map:put($files,$uri,{
                "textDocument":random:uuid(),
                "parse":random:uuid() })
let $keys:=$files($uri)
let $xml:=p:parse-Module($text)

return (
    ws:set($socket,"files",$files),
    ws:set($socket,$keys?textDocument,$textDocument),
    ws:set($socket,$keys?parse,$xml)
) 
};

declare function docs:resolvePosition(text as xs:string, pos as docs:Position) 
as xs:integer
{
  let line = 0, off = 0
  while (line < pos.line) {
    let next = text.indexOf("\n", off)
    if (!next) throw new RangeError("Position out of bounds")
    off = next + 1
    line++
  }
  off += pos.character
  if (off > string-length($text)) throw new RangeError("Position out of bounds")
  return off
}

declare function docs:toPosition($text as xs:string, $pos as xs:integer)
as docs:Position {
  for (let off = 0, line = 0;;) {
    let next = text.indexOf("\n", off)
    if (next < 0 || next >= pos) return {line, character: pos - off}
    off = next + 1
    line++
  }
}