From f0ac5fe7660883cb92c192b175666b4fa03c6281 Mon Sep 17 00:00:00 2001
From: Nicola Belluti <nicolabelluti@protonmail.com>
Date: Sun, 5 May 2024 22:16:48 +0200
Subject: [PATCH] Added the RecordIterator struct

---
 src/lib.rs             |  2 ++
 src/r701.rs            |  5 ++++
 src/record.rs          |  2 +-
 src/record_iterator.rs | 64 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 src/record_iterator.rs

diff --git a/src/lib.rs b/src/lib.rs
index f50a48f..f4568f7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,6 @@
 mod r701;
 mod record;
+mod record_iterator;
 pub use r701::R701;
 pub use record::{Clock, Record};
+pub use record_iterator::RecordIterator;
diff --git a/src/r701.rs b/src/r701.rs
index 4d2cad0..1700dff 100644
--- a/src/r701.rs
+++ b/src/r701.rs
@@ -1,3 +1,4 @@
+use crate::RecordIterator;
 use std::io::{BufRead, BufReader, Error, ErrorKind::InvalidData, Result, Write};
 use std::net::{TcpStream, ToSocketAddrs};
 
@@ -142,4 +143,8 @@ impl R701 {
         // Return only the payload bits as a vector
         Ok(response[12..response.len() - 2].to_vec())
     }
+
+    pub fn iter(&mut self) -> Result<RecordIterator> {
+        RecordIterator::from(self)
+    }
 }
diff --git a/src/record.rs b/src/record.rs
index 79ae136..84cac40 100644
--- a/src/record.rs
+++ b/src/record.rs
@@ -1,6 +1,6 @@
+use chrono::{DateTime, Local, TimeZone};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-use chrono::{DateTime, Local, TimeZone};
 
 #[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/record_iterator.rs b/src/record_iterator.rs
new file mode 100644
index 0000000..d9d5efa
--- /dev/null
+++ b/src/record_iterator.rs
@@ -0,0 +1,64 @@
+use crate::{Record, R701};
+use std::io::Result;
+
+#[derive(Debug)]
+pub struct RecordIterator<'a> {
+    r701: &'a mut R701,
+    input_buffer: Vec<u8>,
+    sequence_number: u16,
+    record_count: u16,
+    total_records: u16,
+}
+
+impl<'a> RecordIterator<'a> {
+    pub fn from(r701: &'a mut R701) -> Result<Self> {
+        // Ping the endpoint
+        r701.ping()?;
+
+        // Get the total number of records
+        let total_records = r701.get_total_record_count()?;
+
+        // Return a new Iterator
+        Ok(Self {
+            r701,
+            input_buffer: Vec::new(),
+            record_count: 0,
+            sequence_number: 0,
+            total_records,
+        })
+    }
+}
+
+impl<'a> Iterator for RecordIterator<'a> {
+    type Item = Record;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.record_count += 1;
+
+        // If we exceeded the total number of records, return None
+        if self.record_count > self.total_records {
+            return None;
+        }
+
+        // If the buffer is empty, make another request to the endpoint asking
+        // for more data
+        if self.input_buffer.len() < 12 {
+            let bytes = &mut self
+                .r701
+                .get_record_bytes(self.total_records, self.sequence_number)
+                .ok()?;
+
+            self.input_buffer.append(bytes);
+            self.sequence_number += 1;
+        }
+
+        // If the record bytes are set to `ff ff ff ff ff ff ff ff ff ff ff ff`,
+        // return None
+        if self.input_buffer[..12] == [0xff_u8; 12] {
+            return None;
+        }
+
+        // Return a new Record
+        self.input_buffer.drain(..12).as_slice().try_into().ok()
+    }
+}