Parse history file

lib/mihainator/csv_parser.ex

@@ -3,7 +3,35 @@ defmodule Mihainator.CSVParser do
 
   def start(file) do
     File.stream!(file)
-    |> Stream.map(&String.split(&1, ","))
-    |> Enum.count()
+    |> CSV.decode!(separator: ?,, headers: true, escape_max_lines: 100)
+    |> Stream.chunk_every(2, 1, :discard)
+    |> Stream.filter(&next_day?/1)
+    |> Stream.map(&extract_data/1)
+    |> Enum.to_list()
+  end
+
+  defp next_day?([%{"posted_at" => current}, %{"posted_at" => next}]) do
+    current =
+      current
+      |> String.to_integer()
+      |> DateTime.from_unix!(:millisecond)
+
+    next =
+      next
+      |> String.to_integer()
+      |> DateTime.from_unix!(:millisecond)
+
+    Date.diff(next, current) == 1
+  end
+
+  defp extract_data([_, %{"isoutbox" => is_out, "posted_at" => posted_at}]) do
+    is_out = is_out == "1"
+
+    posted_at =
+      posted_at
+      |> String.to_integer()
+      |> DateTime.from_unix!(:millisecond)
+
+    [is_out, posted_at]
   end
 end

mix.exs

@@ -53,7 +53,8 @@ defmodule Mihainator.MixProject do
       {:jason, "~> 1.2"},
       {:dns_cluster, "~> 0.1.1"},
       {:bandit, "~> 1.5"},
-      {:credo, "~> 1.7", only: [:dev, :test], runtime: false}
+      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
+      {:csv, "~> 3.2"}
     ]
   end
 

mix.lock

@@ -3,6 +3,7 @@
   "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
   "castore": {:hex, :castore, "1.0.9", "5cc77474afadf02c7c017823f460a17daa7908e991b0cc917febc90e466a375c", [:mix], [], "hexpm", "5ea956504f1ba6f2b4eb707061d8e17870de2bee95fb59d512872c2ef06925e7"},
   "credo": {:hex, :credo, "1.7.8", "9722ba1681e973025908d542ec3d95db5f9c549251ba5b028e251ad8c24ab8c5", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "cb9e87cc64f152f3ed1c6e325e7b894dea8f5ef2e41123bd864e3cd5ceb44968"},
+  "csv": {:hex, :csv, "3.2.1", "6d401f1ed33acb2627682a9ab6021e96d33ca6c1c6bccc243d8f7e2197d032f5", [:mix], [], "hexpm", "8f55a0524923ae49e97ff2642122a2ce7c61e159e7fe1184670b2ce847aee6c8"},
   "dns_cluster": {:hex, :dns_cluster, "0.1.3", "0bc20a2c88ed6cc494f2964075c359f8c2d00e1bf25518a6a6c7fd277c9b0c66", [:mix], [], "hexpm", "46cb7c4a1b3e52c7ad4cbe33ca5079fbde4840dedeafca2baf77996c2da1bc33"},
   "esbuild": {:hex, :esbuild, "0.8.1", "0cbf919f0eccb136d2eeef0df49c4acf55336de864e63594adcea3814f3edf41", [:mix], [{:castore, ">= 0.0.0", [hex: :castore, repo: "hexpm", optional: false]}, {:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "25fc876a67c13cb0a776e7b5d7974851556baeda2085296c14ab48555ea7560f"},
   "file_system": {:hex, :file_system, "1.0.1", "79e8ceaddb0416f8b8cd02a0127bdbababe7bf4a23d2a395b983c1f8b3f73edd", [:mix], [], "hexpm", "4414d1f38863ddf9120720cd976fce5bdde8e91d8283353f0e31850fa89feb9e"},