commit 4b71c945a93641e0e89bf0eddb1fe0eb654c3c42
Author: milarin <milaring@proton.me>
Date:   Fri Jan 13 10:21:45 2023 +0100

    DeterminePriority implemented

diff --git a/determine_priority.go b/determine_priority.go
new file mode 100644
index 0000000..0c4008f
--- /dev/null
+++ b/determine_priority.go
@@ -0,0 +1,28 @@
+package logic
+
+import "git.milar.in/nyaanime/model"
+
+func DeterminePriority(props model.PropertyHolder) (priority int, preferredProperties map[string]int) {
+	preferredProperties = map[string]int{}
+
+	for _, lang := range props.GetLanguages() {
+		if langPriority, ok := PreferredLanguages[lang]; ok {
+			priority += langPriority
+			preferredProperties["lang/"+lang] = langPriority
+		}
+	}
+
+	for _, sub := range props.GetSubtitles() {
+		if subPriority, ok := PreferredSubtitles[sub]; ok {
+			priority += subPriority
+			preferredProperties["sub/"+sub] = subPriority
+		}
+	}
+
+	if prefRes, ok := PreferredResolutions[props.GetResolution()]; ok {
+		priority += prefRes
+		preferredProperties["res/"+props.GetResolution().String()] = prefRes
+	}
+
+	return
+}
diff --git a/envvars.go b/envvars.go
new file mode 100644
index 0000000..a7cf3cf
--- /dev/null
+++ b/envvars.go
@@ -0,0 +1,13 @@
+package logic
+
+import (
+	"git.milar.in/milarin/envvars/v2"
+	"git.milar.in/nyaanime/model"
+)
+
+var (
+	// preferred torrent properties
+	PreferredLanguages   = ParsePreferredStringProps(envvars.StringSlice("PREFERRED_LANGUAGES", "|", []string{}))
+	PreferredSubtitles   = ParsePreferredStringProps(envvars.StringSlice("PREFERRED_SUBTITLES", "|", []string{}))
+	PreferredResolutions = ParsePreferredProps(envvars.StringSlice("PREFERRED_RESOLUTIONS", "|", []string{}), model.ParseResolution)
+)
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..d70f5c0
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,12 @@
+module git.milar.in/nyaanime/logic
+
+go 1.19
+
+require (
+	git.milar.in/milarin/envvars/v2 v2.0.0
+	git.milar.in/milarin/gmath v0.0.3
+	git.milar.in/milarin/slices v0.0.6
+	git.milar.in/nyaanime/model v0.0.0-20221008104642-466e1111ddea
+)
+
+require git.milar.in/milarin/anilist v1.5.0 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..763cd13
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,10 @@
+git.milar.in/milarin/anilist v1.5.0 h1:fSiAXY/topNk4ISEp2QtcG9HHKLJfMc8w05iqc+Paf0=
+git.milar.in/milarin/anilist v1.5.0/go.mod h1:8PTHXFMA45JpfRFIpcdrKwDHue8fbT/wwV1BuHFn6c0=
+git.milar.in/milarin/envvars/v2 v2.0.0 h1:DWRQCWaHqzDD8NGpSgv5tYLuF9A/dVFPAtTvz3oiIqE=
+git.milar.in/milarin/envvars/v2 v2.0.0/go.mod h1:HkdEi+gG2lJSmVq547bTlQV4qQ0hO333bE8IrE0B9yY=
+git.milar.in/milarin/gmath v0.0.3 h1:ii6rKNItS55O/wtIFhD1cTN2BMwDZjTBmiOocKURvxM=
+git.milar.in/milarin/gmath v0.0.3/go.mod h1:HDLftG5RLpiNGKiIWh+O2G1PYkNzyLDADO8Cd/1abiE=
+git.milar.in/milarin/slices v0.0.6 h1:AQoSarZ58WHYol9c6woWJSe8wFpPC2RC4cvIlZpfg9s=
+git.milar.in/milarin/slices v0.0.6/go.mod h1:NOr53AOeur/qscu/FBj3lsFR262PNYBccLYSTCAXRk4=
+git.milar.in/nyaanime/model v0.0.0-20221008104642-466e1111ddea h1:iBwxI3vZ+Hix/5HHB3k9f9/R0nkwR0EvVJ3o5RJEKP4=
+git.milar.in/nyaanime/model v0.0.0-20221008104642-466e1111ddea/go.mod h1:kPWLDvFrhc1Uf77gxsBOxNeJ5JTVF2HhVs1IdVcw0tg=
diff --git a/preferred_props.go b/preferred_props.go
new file mode 100644
index 0000000..53f17e9
--- /dev/null
+++ b/preferred_props.go
@@ -0,0 +1,53 @@
+package logic
+
+import (
+	"strings"
+
+	"git.milar.in/milarin/gmath"
+	"git.milar.in/milarin/slices"
+)
+
+// ParsePreferredProps parses properties and its corresponding priority.
+// priorities are distributed exponentially in reverse order.
+//
+// That means the last entry will have priority 1, the second last 2, then 4, 8 and so on.
+//
+// Properties with name "_" will be ignored and function as a placeholder to increase the priority
+// of the properties which comes before them.
+//
+// Properties separated by comma will have the same priorities.
+//
+// str usually is the return value of a call to strings.Split(str, "|")
+//
+// Examples:
+// str = "a|b|c"       -> c:1 b:2 a:4
+// str = "a|b|_|c"     -> c:1 b:4 a:8
+// str = "a,b|c"       -> c:1 b:4 a:4
+// str = "d|_|a,b|c"   -> c:1 b:4 a:4 d:16
+//
+// Additionally, properties can be converted to a generic type with the converter function
+func ParsePreferredProps[T comparable](str []string, converter func(string) (T, error)) map[T]int {
+	props := map[T]int{}
+
+	for i, subProps := range slices.Reverse(str) {
+		if subProps == "_" {
+			continue
+		}
+
+		propPriority := gmath.Pow(2, i)
+		for _, subProp := range strings.Split(subProps, ",") {
+			subPropT, err := converter(subProp)
+			if err != nil {
+				continue
+			}
+
+			props[subPropT] = propPriority
+		}
+	}
+
+	return props
+}
+
+func ParsePreferredStringProps(str []string) map[string]int {
+	return ParsePreferredProps(str, func(s string) (string, error) { return s, nil })
+}