From 7584c3acc0391b69806f219b3e50a2caa526ea3d Mon Sep 17 00:00:00 2001
From: Karchnu <karchnu@karchnu.fr>
Date: Fri, 26 Apr 2024 19:35:00 +0200
Subject: [PATCH] Rewrite of the tag mechanism. Tests are needed.

---
 spec/test.cr     |   2 +-
 src/dodb/tags.cr | 116 ++++++++++++++++++++++++-----------------------
 2 files changed, 61 insertions(+), 57 deletions(-)

diff --git a/spec/test.cr b/spec/test.cr
index 456da00..13e0685 100644
--- a/spec/test.cr
+++ b/spec/test.cr
@@ -277,7 +277,7 @@ describe "DODB::DataBase" do
 			end
 
 			# Removing the “flagship” tag, brace for impact.
-			flagship, index = db_ships_by_tags.get_with_indices("flagship")[0]
+			flagship, index = db_ships_by_tags.get_with_indice("flagship")[0]
 			flagship.tags = [] of String
 			db[index] = flagship
 
diff --git a/src/dodb/tags.cr b/src/dodb/tags.cr
index f7b0e85..1e269fc 100644
--- a/src/dodb/tags.cr
+++ b/src/dodb/tags.cr
@@ -10,48 +10,27 @@ class DODB::Tags(V) < DODB::Indexer(V)
 		::Dir.mkdir_p indexing_directory
 	end
 
-	# FIXME: The slow is damn too high.
-	def tag_combinations(tags)
-		combinations = [] of Array(String)
-
-		tags.size.times do |i|
-			combinations.concat tags.permutations (i+1)
-		end
-
-		return combinations
+	def check!(key, value, old_value)
+		return true # Tags don’t have collisions or overloads.
 	end
 
 	def index(key, value)
-		indices = key_proc.call(value).sort
-
-		tag_combinations(indices).each do |previous_indices|
-			# FIXME: Not on `index`, but on the list of all previous indices.
-			symdir = symlinks_directory previous_indices
-			otdir  = other_tags_directory previous_indices
-
-			::Dir.mkdir_p symdir
-			::Dir.mkdir_p otdir
-
-			symlink = get_tagged_entry_path(key, previous_indices)
+		indices = key_proc.call(value)
 
+		indices.each do |i|
+			symlink = get_tagged_entry_path(i, key)
+			Dir.mkdir_p ::File.dirname symlink
+			# FIXME: Should not happen anymore. Should we remove this?
 			::File.delete symlink if ::File.exists? symlink
-
-			::File.symlink get_data_symlink(key, previous_indices), symlink
+			::File.symlink get_data_symlink(key), symlink
 		end
 	end
 
 	def deindex(key, value)
-		indices = key_proc.call(value).sort
+		indices = key_proc.call(value)
 
-		tag_combinations(indices).each do |previous_indices|
-			# FIXME: Not on `index`, but on the list of all previous indices.
-			symdir = symlinks_directory previous_indices
-			otdir  = other_tags_directory previous_indices
-
-			::Dir.mkdir_p symdir
-			::Dir.mkdir_p otdir
-
-			symlink = get_tagged_entry_path(key, previous_indices)
+		indices.each do |i|
+			symlink = get_tagged_entry_path(i, key)
 
 			::File.delete symlink if ::File.exists? symlink
 
@@ -59,24 +38,16 @@ class DODB::Tags(V) < DODB::Indexer(V)
 		end
 	end
 
-	def check!(key, value, old_value)
-		return true # Tags don’t have collisions or overloads.
-	end
-
-	def get_with_indices(key : String) : Array(Tuple(V, Int32))
-		get_with_indices [key]
-	end
-
-	def get_with_indices(keys : Array(String)) : Array(Tuple(V, Int32))
+	def get_with_indice(tag : String) : Array(Tuple(V, Int32))
 		r_value = Array(Tuple(V, Int32)).new
 
-		partition_directory = symlinks_directory keys
+		tag_directory = indexing_directory tag
 
-		return r_value unless Dir.exists? partition_directory
+		return r_value unless Dir.exists? tag_directory
 
-		Dir.each_child partition_directory do |child|
+		Dir.each_child tag_directory do |child|
 			r_value << {
-				V.from_json(::File.read("#{partition_directory}/#{child}")),
+				V.from_json(::File.read("#{tag_directory}/#{child}")),
 				File.basename(child).gsub(/\.json$/, "").to_i
 			}
 		end
@@ -84,30 +55,63 @@ class DODB::Tags(V) < DODB::Indexer(V)
 		r_value
 	end
 
-	def get(key : String) : Array(V)
-		get_with_indices(key).map &.[0]
+	def get_with_indices(keys : Array(String)) : Array(Tuple(V, Int32))
+		r_value = Array(Tuple(V, Int32)).new
+		keys.each do |tag|
+			r_value.concat get_with_indice tag
+		end
+		r_value
+	end
+
+	def get(tag : String) : Array(V)
+		get_with_indice(tag).map &.[0]
 	end
 
 	def get(keys : Array(String)) : Array(V)
 		get_with_indices(keys.sort).map &.[0]
 	end
 
+	def delete(tag)
+		delete tag, do true end
+	end
+
+	def delete(tag, &matcher)
+		tag_directory = indexing_directory tag
+
+		return unless Dir.exists? tag_directory
+
+		Dir.each_child tag_directory do |child|
+			path = "#{tag_directory}/#{child}"
+			item = V.from_json ::File.read path
+
+			if yield item
+				key = get_key path
+				@storage.delete key
+			end
+		end
+	end
+
+	private def get_key(path : String) : Int32
+		::File.readlink(path)
+			.sub(/\.json$/, "")
+			.sub(/^.*\//,   "")
+			.to_i
+	end
+
 	def indexing_directory : String
 		"#{@storage_root}/tags/by_#{@name}"
 	end
 
-	private def symlinks_directory(previous_indices : Array(String))
-		"#{indexing_directory}#{previous_indices.map { |i| "/other-tags/#{i}" }.join}/data"
-	end
-	private def other_tags_directory(previous_indices : Array(String))
-		"#{indexing_directory}#{previous_indices.map { |i| "/other-tags/#{i}" }.join}/other-tags"
+	private def indexing_directory(tag)
+		"#{indexing_directory}/#{tag}"
 	end
 
-	private def get_tagged_entry_path(key : String, indices : Array(String))
-		"#{indexing_directory}#{indices.map { |i| "/other-tags/#{i}" }.join}/data/#{key}.json"
+	private def get_tagged_entry_path(tag : String, key : String)
+		"#{indexing_directory}/#{tag}/#{key}.json"
 	end
-	private def get_data_symlink(key : String, indices : Array(String))
-		"../../../#{indices.map { "../../" }.join}/data/#{key}.json"
+
+	private def get_data_symlink(key : String)
+		"../../../data/#{key}.json"
 	end
 end