initial file browser work

rust/src/plant_hal.rs

@@ -26,8 +26,10 @@ use plant_ctrl2::sipo::ShiftRegister40;
 
 use anyhow::{anyhow, Context};
 use anyhow::{bail, Ok, Result};
+use serde::Serialize;
 use std::ffi::CString;
-use std::fs::File;
+use std::fs::{self, DirEntry, File};
+use std::io::{Read, Write};
 use std::path::Path;
 
 use chrono::{DateTime, Utc};
@@ -60,6 +62,7 @@ const REPEAT_MOIST_MEASURE: usize = 1;
 
 const SPIFFS_PARTITION_NAME: &str = "storage";
 const CONFIG_FILE: &str = "/spiffs/config.cfg";
+const BASE_PATH: &str = "/spiffs";
 
 const TANK_MULTI_SAMPLE: usize = 11;
 
@@ -165,7 +168,34 @@ pub struct PlantCtrlBoard<'a> {
     >,
 }
 
+#[derive(Serialize, Debug)]
+pub struct FileInfo{
+    filename:String,
+    size:usize
+}
+
 impl PlantCtrlBoard<'_> {
+    pub fn list_files(&self) -> Result<Vec<FileInfo>> {
+        let spiffs = Path::new(BASE_PATH);
+        let list = fs::read_dir(spiffs).unwrap().map(|dir| {
+            let file = dir.unwrap();
+            FileInfo{
+                filename: file.file_name().into_string().unwrap(),
+                size: file.metadata().unwrap().len() as usize
+            }
+        });
+        return Ok(list.collect());
+    }
+
+    pub fn get_file_handle(&self, filename:String, write:bool) -> Result<File> {
+        let filepath = Path::new(BASE_PATH).join(Path::new(&filename));
+        return Ok(if write {
+            File::create(filepath)?
+        } else {
+            File::open(filepath)?
+        })
+    }
+
     pub fn is_day(&self) -> bool {
         self.solar_is_day.get_level().into()
     }