#!/usr/bin/env bash

assignTags(){
	local filename
	local tags
	local tagIDs
	local tagIDsOr
	local fileID
	filename="$(findFile "$1")"
	[ ! -e "$filename" ] && exit 1
	tags="$(cat - | sed '/^$/d')"
	fileID="$(findFileId "$filename")"
	# If there are tags
	if [ -n "$tags" ]; then
		local values
		local orlist
		while read -r line; do
			values+=",('$(safeSQL "$line")')"
			orlist+=" OR name = '$(safeSQL "$line")'"
		done <<<"$(echo "$tags")"
		values="$(echo "$values" | sed 's/^,//')"
		orlist="$(echo "$orlist" | sed 's/^ OR //')"
		
		# Ensure that all the tags exist
		echo "INSERT INTO tags (name) VALUES $values
			EXCEPT SELECT name FROM tags;" |
				sqlite3 "${sqliteFile}"

		# Get the tag ids we need to assosiate with the current file
		tagIDs="$(echo "SELECT id FROM tags WHERE $orlist" |
			sqlite3 "${sqliteFile}")"
		
		#Loop through them all
		while read -r tagID; do
			tagIDsOr+=" OR tagID = $(safeSQL "$tagID")"
			
			# Check the tag is already linkded with the file
			local existing
			existing="$(echo "SELECT id FROM links
				WHERE itemID = $(safeSQL "$fileID")
				AND tagID = $(safeSQL "$tagID")" |
				sqlite3 "${sqliteFile}"
			)"

			# If not, add a link
			if [ -z "$existing" ]; then
				echo "INSERT INTO links (itemID,tagID)
				VALUES ($(safeSQL "$fileID"),$(safeSQL "$tagID"))" |
				sqlite3 "${sqliteFile}"
			fi
		done <<<"$(echo "$tagIDs")"
		tagIDsOr="$(echo "$tagIDsOr" | sed 's/^ OR //')"

		# Delete any links that are not in the list
		echo "DELETE FROM links
		WHERE itemID = $(safeSQL "$fileID")
		AND NOT ( $tagIDsOr )" |
		sqlite3 "${sqliteFile}"

	else # If there are no tags, simply delete any that are referenced
		echo "DELETE FROM links WHERE itemID = '$(safeSQL "$fileID")'" |
			sqlite3 "${sqliteFile}"
	fi
	

}

listTags(){
	vecho "listTags $*"
	cd "$dataDir" || return
	local header="--header"
	[ "$1" = "--noheader" ] && header=""
	echo "SELECT tags.name,COUNT(links.id) count
		FROM tags LEFT JOIN links ON tags.id = links.tagID
		GROUP BY tags.id" |
		sqlite3 --column $header "${sqliteFile}"
}

purgeTags(){
	vecho "purgeTags $*"
	echo "DELETE FROM tags WHERE id IN (
		SELECT id FROM tags WHERE id NOT IN (SELECT tagID FROM links)
	)"| sqlite3 --column --header "${sqliteFile}"
}