From 2b7f7849518e1dd07f492188d8b62f9842d71b3a Mon Sep 17 00:00:00 2001
From: Ryan Pandya <ryan@pandu.ski>
Date: Tue, 30 Aug 2022 13:10:23 -0700
Subject: [PATCH] Implemented very rudimentary sync conflict detection and api
 endpoint /conflicts.

---
 logsrv_api/lib/logsrv.ex         | 59 ++++++++++++++++++++++++++++++--
 logsrv_api/lib/logsrv/helpers.ex | 14 ++++++++
 logsrv_api/lib/logsrv/router.ex  |  9 +++++
 3 files changed, 80 insertions(+), 2 deletions(-)
 create mode 100644 logsrv_api/lib/logsrv/helpers.ex

diff --git a/logsrv_api/lib/logsrv.ex b/logsrv_api/lib/logsrv.ex
index 22960c2..dc30094 100644
--- a/logsrv_api/lib/logsrv.ex
+++ b/logsrv_api/lib/logsrv.ex
@@ -4,11 +4,11 @@ defmodule Logsrv do
   """
 
   def dir do
-    Application.get_env(:logsrv, :dir)
+    Application.get_env(:logsrv, :dir) <> "/"
   end
 
   def dir(subdir) do
-    "#{dir()}/#{subdir}"
+    "#{dir()}/#{subdir}/"
   end
 
   def journals do
@@ -21,4 +21,59 @@ defmodule Logsrv do
     |> File.ls!
   end
 
+  def compare(fd) do
+    sync_conflict_fd = fd
+    orig_fd = fd
+      |> String.replace(~r/\.sync.*/,"\.md")
+
+    sync_conflict = sync_conflict_fd |> File.read!
+    orig = orig_fd |> File.read!
+
+    # FOR NOW, just return the diff
+    diff = orig
+      |> String.myers_difference(sync_conflict)
+
+    diff
+    |> Kernel.inspect()
+    |> Jason.encode!
+
+  end
+
+  def conflicts do
+    {conflicts(journals()), conflicts(pages())}
+  end
+
+  def conflicts(list) do
+    list
+    |> Enum.filter( fn (fd) ->
+    fd |> String.match?(~r/.*sync.*/)
+    end)
+  end
+
+  def resolve_conflicts do
+    {journal_conflicts, pages_conflicts} = conflicts()
+
+    [
+      journal_conflicts
+    |> Enum.map( fn(fd) ->
+      %{
+        :type => :journal,
+        :date => fd |> Logsrv.Helpers.to_date,
+        :file => fd,
+        :diff => compare(dir(:journals) <> fd),
+      }
+    end),
+
+    pages_conflicts
+    |> Enum.map( fn(fd) ->
+      %{
+        :type => :page,
+        :file => fd,
+        :diff => compare(dir(:pages) <> fd),
+      }    end)
+        ]
+    |> List.flatten()
+
+  end
+
 end
diff --git a/logsrv_api/lib/logsrv/helpers.ex b/logsrv_api/lib/logsrv/helpers.ex
new file mode 100644
index 0000000..9383dbd
--- /dev/null
+++ b/logsrv_api/lib/logsrv/helpers.ex
@@ -0,0 +1,14 @@
+defmodule Logsrv.Helpers do
+
+  def moot do
+    "moo"
+  end
+
+  def to_date(str) do
+    str
+    |> String.replace(~r/\..*/,"")
+    |> String.replace("_","-")
+    |> Date.from_iso8601!()
+  end
+
+end
diff --git a/logsrv_api/lib/logsrv/router.ex b/logsrv_api/lib/logsrv/router.ex
index 0ec0e25..d258b1b 100644
--- a/logsrv_api/lib/logsrv/router.ex
+++ b/logsrv_api/lib/logsrv/router.ex
@@ -45,6 +45,15 @@ defmodule Logsrv.Router do
     |> send_resp(200, pages) # Send a 200 OK response with the posts in the body
   end
 
+  get "/conflicts" do
+    conflicts = Logsrv.resolve_conflicts
+    |> Jason.encode!
+
+    conn
+    |> put_resp_content_type("application/json")
+    |> send_resp(200, conflicts) # Send a 200 OK response with the conflicts
+  end
+
   # Fallback handler when there was no match
   match _ do
     send_resp(conn, 404, "Not Found")