From f5d288f64bff1739b79f99e2accdf0aa7886af4a Mon Sep 17 00:00:00 2001
From: Folkert Kevelam <contact@pyllr.nl>
Date: Tue, 8 Oct 2024 22:13:51 +0200
Subject: [PATCH] Initial commit

---
 lua/SpecSwitcher/path.lua | 98 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 lua/SpecSwitcher/path.lua

diff --git a/lua/SpecSwitcher/path.lua b/lua/SpecSwitcher/path.lua
new file mode 100644
index 0000000..c980473
--- /dev/null
+++ b/lua/SpecSwitcher/path.lua
@@ -0,0 +1,98 @@
+local path = {}
+
+function path.Common_Root( Left, Right, Separator )
+    local Sep = Separator or "/"
+    local smallest_string = nil
+    local largest_string = nil
+    if string.len(Left) > string.len(Right) then
+        smallest_string = Right
+        largest_string = Left
+    else
+        smallest_string = Left
+        largest_string = Right
+    end
+
+    local last_sep_idx = 1
+    local sep = string.byte(Sep)
+    for i = 1, #smallest_string do
+        if smallest_string:byte(i) == sep then
+            last_sep_idx = i
+        end
+
+        if smallest_string:byte(i) ~= largest_string:byte(i) then
+            break
+        end
+    end
+
+    local match = string.sub(smallest_string, 1, last_sep_idx - 1)
+
+    if match == '' then
+        return nil
+    else
+        return match
+    end
+end
+
+function path.Get_Extension( P )
+    if P == nil then
+        return nil
+    end
+
+    local rev_string = string.reverse(P)
+    local start_idx = 0
+    local end_idx = 0
+    start_idx, end_idx = string.find(rev_string, ".", 1, true)
+
+    if start_idx == nil then
+        return nil
+    else
+        return string.sub(P, #P - (start_idx -2))
+    end
+end
+
+function path.Get_Extension_From_List( P, Extension_List )
+    if Extension_List == nil or P == nil then
+        return nil
+    end
+
+    local ext_length = 0
+    for _,item in ipairs(Extension_List) do
+        local current_ext_length = #item
+        if current_ext_length > ext_length then
+            ext_length = current_ext_length
+        end
+    end
+
+    local rev_string = string.reverse(P)
+    local start_idx = 0
+    local end_idx = 0
+    local match = nil
+    while ( true ) do
+        start_idx, end_idx = string.find(rev_string, ".", start_idx+1, true)
+        if start_idx == nil or (start_idx-1) > ext_length then
+            break
+        end
+
+        for _,exts in ipairs(Extension_List) do
+            if exts == string.sub(P, #P - (start_idx -2)) then
+                match = exts
+            end
+        end
+    end
+
+    return match
+end
+
+function path.Get_Ext( P, Extension_List )
+    if Extension_List == nil then
+        return path.Get_Extension(P)
+    else
+        return path.Get_Extension_From_List(P, Extension_List)
+    end
+end
+
+print(path.Common_Root("/home/folkert/Documents/Projects","/home/folkert/Downloads/sub/sub2/sub3/sub4/hello.txt"))
+print(path.Get_Ext("/home/folkert/Documents/projects.wo.cp", {"o.cp"}))
+
+
+return path