From 0906e227d57c12672a0c8b23cbb20b7b937ae394 Mon Sep 17 00:00:00 2001
From: Ivan Yuriev <ivanyr44@gmail.com>
Date: Fri, 13 Dec 2024 18:12:55 +0300
Subject: [PATCH] improved shutdown

---
 src/forest.gleam      | 29 +++++++++++++++++---------
 src/tree_events.gleam |  4 +++-
 src/treevault.gleam   | 47 +++++++++++++++++++++++++++++--------------
 3 files changed, 54 insertions(+), 26 deletions(-)

diff --git a/src/forest.gleam b/src/forest.gleam
index 1b974d6..2a17e04 100644
--- a/src/forest.gleam
+++ b/src/forest.gleam
@@ -2,6 +2,7 @@ import gleam/dict.{type Dict}
 import gleam/erlang/process.{type Subject}
 import gleam/list
 import gleam/otp/actor
+import gleam/string
 
 import gleam/result.{try}
 import json_serde
@@ -9,7 +10,7 @@ import query
 import simplifile
 import tree
 import tree_events.{
-  type TreeEvents, GetEvent, RecursiveGetEvent, SetEvent, Shutdown,
+  type TreeEvents, GetEvent, RecursiveGetEvent, SetEvent, Shutdown, Snapshot,
 }
 
 pub type Message {
@@ -95,8 +96,8 @@ fn handle_message(event: TreeEvents, tree) {
     SetEvent(path, data, client) -> {
       let res = query.set(tree, path, data)
       case res {
-        Error(_) -> {
-          actor.send(client, res |> result.map(fn(_) { "Ok" }))
+        Error(err) -> {
+          actor.send(client, res |> result.map(fn(_) { err |> string.inspect }))
           actor.continue(tree)
         }
         Ok(tree) -> {
@@ -105,13 +106,21 @@ fn handle_message(event: TreeEvents, tree) {
         }
       }
     }
-    Shutdown(filepath) -> {
-      let json = tree |> json_serde.serialize()
-      case simplifile.write(filepath, json) {
-        Error(err) ->
-          actor.Stop(process.Abnormal(err |> simplifile.describe_error))
-        Ok(_) -> actor.Stop(process.Normal)
-      }
+    Snapshot(filepath, client) -> {
+      actor.send(client, snapshot(tree, filepath))
+      actor.continue(tree)
+    }
+
+    Shutdown -> {
+      actor.Stop(process.Normal)
     }
   }
 }
+
+fn snapshot(tree, filepath) {
+  let json = tree |> json_serde.serialize()
+  case simplifile.write(filepath, json) {
+    Error(err) -> Error(err |> simplifile.describe_error)
+    Ok(_) -> Ok("Ok")
+  }
+}
diff --git a/src/tree_events.gleam b/src/tree_events.gleam
index 20b32da..823204d 100644
--- a/src/tree_events.gleam
+++ b/src/tree_events.gleam
@@ -16,5 +16,7 @@ pub type TreeEvents {
     reply_with: Subject(Result(String, QueryError)),
   )
 
-  Shutdown(filepath: String)
+  Snapshot(filepath: String, reply_with: Subject(Result(String, String)))
+
+  Shutdown
 }
diff --git a/src/treevault.gleam b/src/treevault.gleam
index 771a276..268ae45 100644
--- a/src/treevault.gleam
+++ b/src/treevault.gleam
@@ -12,13 +12,18 @@ import gleam/otp/actor
 import gleam/string
 import gleam_community/ansi
 import glisten
+import query
+import query_error
 import spinner
 import tree_events
 
-import query
-import query_error
-
 pub fn main() {
+  init()
+
+  process.sleep_forever()
+}
+
+fn init() {
   let config = config.load("./config.json") |> io.debug
   let forest = case forest.load(config.snapshots_path, config.forest) {
     Error(err) -> {
@@ -63,7 +68,6 @@ pub fn main() {
           }
         }
       }
-
       actor.continue(state)
     })
     |> glisten.serve(config.port)
@@ -90,19 +94,14 @@ fn read_next(forest) {
       case term {
         "exit\n" -> {
           graceful(forest)
-          let spinner =
-            spinner.new("Shutting down...")
-            |> spinner.with_colour(ansi.pink)
-            |> spinner.start
-          process.sleep(5000)
-          "Bye" |> io.println
-          spinner |> spinner.stop
         }
         "help\n" -> {
-          "Available commands: " |> io.println
-          "exit" |> io.println
+          "Available commands:\n" |> io.println
+          "help\n" |> io.println
+          "exit\n" |> io.println
           read_next(forest)
         }
+
         _ -> {
           "Unknown command" |> io.println
           read_next(forest)
@@ -113,13 +112,31 @@ fn read_next(forest) {
 }
 
 fn graceful(forest: forest.Forest) {
+  let spinner =
+    spinner.new("Shutting down...")
+    |> spinner.with_colour(ansi.pink)
+    |> spinner.start
+
   forest.trees
   |> dict.to_list
-  |> list.map(fn(tree) {
+  |> list.each(fn(tree) {
     let ps = tree.1.1
     let path = tree.1.0
 
-    ps |> process.send(tree_events.Shutdown(path))
     { "Exiting: " <> tree.0 } |> io.println
+    let res =
+      ps
+      |> process.call_forever(fn(actor) { tree_events.Snapshot(path, actor) })
+    case res {
+      Ok(ok) -> ok
+      Error(err) -> err
+    }
+    |> io.println
+
+    ps |> process.send(tree_events.Shutdown)
   })
+
+  process.sleep(1000)
+  "Bye" |> io.println
+  spinner |> spinner.stop
 }