feat: Implement --get command to retrieve items by ID or tag with compression handling

src/modes/get.rs

@@ -4,3 +4,51 @@ use clap::Command;
 
 use crate::db;
 use crate::compression::{CompressionType, get_engine};
+use anyhow::Context;
+use clap::Command;
+use crate::db::Item;
+use crate::db::Meta;
+use crate::compression::CompressionEngine;
+use std::path::PathBuf;
+
+pub fn mode_get(
+    cmd: &mut Command,
+    args: crate::Args,
+    ids: &mut Vec<i64>,
+    tags: &mut Vec<String>,
+    conn: &mut crate::db::Connection,
+    data_path: PathBuf,
+) -> anyhow::Result<()> {
+    if !ids.is_empty() && !tags.is_empty() {
+        cmd.error(clap::error::ErrorKind::InvalidValue, "Both ID and tags given, you must supply exactly one ID or at least one tag when using --get").exit();
+    } else if ids.len() > 1 {
+        cmd.error(clap::error::ErrorKind::InvalidValue, "More than one ID given, you must supply exactly one ID or at least one tag when using --get").exit();
+    }
+
+    let mut meta: std::collections::HashMap<String, String> = std::collections::HashMap::new();
+    for item in args.item.meta.iter() {
+        let item = item.clone();
+        meta.insert(item.key, item.value);
+    }
+
+    let item_maybe = match tags.is_empty() && meta.is_empty() {
+        true => match ids.iter().next() {
+            Some(item_id) => crate::db::get_item(conn, *item_id)?,
+            None => crate::db::get_item_last(conn)?
+        },
+        false => crate::db::get_item_matching(conn, tags, &meta)?
+    };
+
+    if let Some(item) = item_maybe {
+        let mut item_path = data_path.clone();
+        item_path.push(item.id.unwrap().to_string());
+
+        let compression_type = crate::compression::CompressionType::from_str(&item.compression)?;
+        let compression_engine = crate::compression::get_engine(compression_type)?;
+        compression_engine.cat(item_path.clone())?;
+
+        Ok(())
+    } else {
+        Err(anyhow!("Unable to find matching item in database"))
+    }
+}