Create blog_engine.exs

Author: danglinhanh

blog_engine.exs

@@ -0,0 +1,98 @@
+defmodule BlogEngine do
+  defmodule Post do
+    defstruct [:id, :title, :body, :created_at]
+  end
+
+  def start do
+    IO.puts("Welcome to the Elixir Blog Engine CLI")
+    loop([], 1)
+  end
+
+  defp loop(posts, next_id) do
+    IO.puts("\nAvailable commands:")
+    IO.puts("  new         - Create a new post")
+    IO.puts("  list        - List all posts")
+    IO.puts("  view [id]   - View a post by ID")
+    IO.puts("  delete [id] - Delete a post by ID")
+    IO.puts("  quit        - Exit the app")
+
+    case IO.gets("\nCommand> ") |> String.trim() do
+      "new" ->
+        {post, new_id} = create_post(next_id)
+        loop([post | posts], new_id)
+
+      "list" ->
+        list_posts(posts)
+        loop(posts, next_id)
+
+      "quit" ->
+        IO.puts("Goodbye!")
+
+      cmd when String.starts_with?(cmd, "view ") ->
+        [_ | [id_str]] = String.split(cmd)
+        view_post(posts, String.to_integer(id_str))
+        loop(posts, next_id)
+
+      cmd when String.starts_with?(cmd, "delete ") ->
+        [_ | [id_str]] = String.split(cmd)
+        updated_posts = delete_post(posts, String.to_integer(id_str))
+        loop(updated_posts, next_id)
+
+      _ ->
+        IO.puts("Invalid command.")
+        loop(posts, next_id)
+    end
+  end
+
+  defp create_post(id) do
+    title = IO.gets("Title: ") |> String.trim()
+    body = IO.gets("Body: ") |> String.trim()
+    created_at = DateTime.utc_now() |> DateTime.to_string()
+
+    post = %Post{
+      id: id,
+      title: title,
+      body: body,
+      created_at: created_at
+    }
+
+    IO.puts("Post created with ID #{id}.")
+    {post, id + 1}
+  end
+
+  defp list_posts([]) do
+    IO.puts("No posts available.")
+  end
+
+  defp list_posts(posts) do
+    IO.puts("\nPosts:")
+    Enum.each(Enum.reverse(posts), fn post ->
+      IO.puts("  [#{post.id}] #{post.title} (#{post.created_at})")
+    end)
+  end
+
+  defp view_post(posts, id) do
+    case Enum.find(posts, fn p -> p.id == id end) do
+      nil ->
+        IO.puts("Post not found.")
+      post ->
+        IO.puts("\n--- Post ##{post.id} ---")
+        IO.puts("Title: #{post.title}")
+        IO.puts("Created: #{post.created_at}")
+        IO.puts("Body:\n#{post.body}")
+    end
+  end
+
+  defp delete_post(posts, id) do
+    case Enum.find(posts, fn p -> p.id == id end) do
+      nil ->
+        IO.puts("Post not found.")
+        posts
+      _ ->
+        IO.puts("Post #{id} deleted.")
+        Enum.reject(posts, fn p -> p.id == id end)
+    end
+  end
+end
+
+BlogEngine.start()