add priority subcommand

src/cli.rs

@@ -34,4 +34,15 @@ pub enum SubCommand {
     Remove {
         idx: usize,
     },
+    Priority {
+        idx: usize,
+        #[clap(subcommand)]
+        priority: Priority,
+    },
+}
+
+#[derive(Parser)]
+pub enum Priority {
+    Before { idx: usize },
+    After { idx: usize },
 }

src/main.rs

@@ -1,6 +1,9 @@
 use clap::Parser;
 use serde::{Deserialize, Serialize};
-use std::io::{BufRead, Write};
+use std::{
+    cmp::Ordering,
+    io::{BufRead, Write},
+};
 use xdg::BaseDirectories;
 
 mod cli;
@@ -94,6 +97,44 @@ fn main() {
                 println!("{}", task.name);
             }
         }
+        cli::SubCommand::Priority {
+            idx: target_idx,
+            priority,
+        } => {
+            if target_idx == 0 || target_idx > tasks.len() {
+                println!("invalid index");
+            }
+
+            let idx = match priority {
+                cli::Priority::Before { idx } | cli::Priority::After { idx } => {
+                    match target_idx.cmp(&idx) {
+                        Ordering::Equal => return,
+                        Ordering::Less => idx - 1,
+                        Ordering::Greater => idx,
+                    }
+                }
+            };
+            if idx == 0 || idx > tasks.len() {
+                println!("invalid index");
+            }
+
+            let target = tasks.remove(target_idx - 1);
+
+            match priority {
+                cli::Priority::Before { .. } => {
+                    tasks.insert(idx - 1, target);
+                    println!("{} < {}", target_idx, idx);
+                }
+                cli::Priority::After { .. } => {
+                    tasks.insert(idx, target);
+                    println!("{} > {}", target_idx, idx);
+                }
+            }
+
+            let mut file = std::fs::File::create(&tasks_file_path).unwrap();
+            file.write_all(&serde_json::to_vec(&tasks).unwrap())
+                .unwrap();
+        }
         cli::SubCommand::Start => {
             println!("starting...");
             println!("-- on start hook found");