cassiopeia: finishing up version 0.3.0

This commit does kind of a lot to get cass(1) over the finish line.
For one it implements all the CLI functions (well, almost all) with
their respective parameters, and also creates a new `gen` module which
uses the IR stream to generate a new file based on the old one, while
updating header fields that need to be updated (currently only
`version`).

This version does nothing with the actual header values, and probably
has a lot of bugs.  More documentation will follow in future
cassiopeia commits.

3 files changed, 97 insertions, 7 deletions

diff --git a/apps/cassiopeia/src/format/gen.rs b/apps/cassiopeia/src/format/gen.rs
new file mode 100644
index 000000000000..2bcd6cc724fd
--- /dev/null
+++ b/apps/cassiopeia/src/format/gen.rs
@@ -0,0 +1,33 @@
+//! Cassiopeia line generator
+//!
+//! This module takes a set of IR lines, and generates strings from
+//! them that are in accordance with the way that the parser of the
+//! same version expects them.
+
+use crate::format::ir::{IrItem, IrType};
+
+/// Take a line of IR and generate a string to print into a file
+pub(crate) fn line(ir: &IrItem) -> String {
+    let IrItem { tt, lo } = ir;
+    match tt {
+        IrType::Ignore => "".into(),
+        IrType::Header(map) => format!(
+            "HEADER {}",
+            map.iter()
+                .map(|(k, v)| format!("{}={},", k, v))
+                .collect::<Vec<_>>()
+                .join("")
+        ),
+        IrType::Start(time) => format!("START {}", time.to_string()),
+        
+        // FIXME: find a better way to align the lines here rather
+        // than having to manually having to pad the 'STOP' commands
+        IrType::Stop(time) => format!("STOP  {}", time.to_string()),
+        IrType::Invoice(date) => format!("INVOICE {}", date.to_string()),
+    }
+}
+
+pub(crate) fn head_comment() -> String {
+    ";; generated by cassiopeia, be careful about editing by hand!".into()
+}
+
diff --git a/apps/cassiopeia/src/format/ir.rs b/apps/cassiopeia/src/format/ir.rs
index 32922ec079e7..09a54e810615 100644
--- a/apps/cassiopeia/src/format/ir.rs
+++ b/apps/cassiopeia/src/format/ir.rs
@@ -44,7 +44,7 @@ pub(crate) fn generate_ir(buf: impl Iterator<Item = LineCfg>) -> IrStream {
     buf.enumerate().fold(vec![], |mut buf, (lo, item)| {
         #[cfg_attr(rustfmt, rustfmt_skip)]
         buf.push(match item {
-            LineCfg::Header(map) => IrItem { tt: IrType::Header(map), lo },
+            LineCfg::Header(map) => IrItem { tt: IrType::Header(map.into_iter().map(|(k, v)| (k, v.replace(",", ""))).collect()), lo },
             LineCfg::Start(Some(time)) => IrItem { tt: IrType::Start(time.into()), lo },
             LineCfg::Stop(Some(time)) => IrItem { tt: IrType::Stop(time.into()), lo },
             LineCfg::Invoice(Some(date)) => IrItem { tt: IrType::Invoice(date.into()), lo },
@@ -56,8 +56,45 @@ pub(crate) fn generate_ir(buf: impl Iterator<Item = LineCfg>) -> IrStream {
     })
 }
 
-
 pub(crate) trait MakeIr {
     /// Make a new IR line from an object
     fn make_ir(&self) -> IrType;
 }
+
+pub(crate) fn clean_ir(ir: &mut IrStream) {
+    ir.remove(0); // FIXME: this is required to remove the leading
+    // comment, which will be manually re-generated at
+    // the moment, but which would just add more blank
+    // lines between the new comment, and the first line
+    // in this current format.  This is very bad, yikes
+    // yikes yikes, but what can I do, I have a deadline
+    // (not really) lol
+
+    // FIXME: this hack gets rid of a trailing empty line if it exists
+    // to make sure we don't have any gaps between work sessions.
+    if match ir.last() {
+        Some(IrItem {
+            tt: IrType::Ignore, ..
+        }) => true,
+        _ => false,
+    } {
+        ir.pop();
+    }
+}
+    
+/// Taken an IrType and append it to an existing IR stream
+pub(crate) fn append_ir(ir: &mut IrStream, tt: IrType) {
+
+    let lo = ir.last().unwrap().lo;
+    ir.push(IrItem { tt, lo });
+}
+
+/// Search for the header that contains the version string and update it
+pub(crate) fn update_header(ir: &mut IrStream) {
+    ir.iter_mut().for_each(|item| match item.tt {
+        IrType::Header(ref mut map) if map.contains_key("version") => {
+            map.insert("version".into(), crate::meta::VERSION.into());
+        }
+        _ => {}
+    });
+}
diff --git a/apps/cassiopeia/src/format/mod.rs b/apps/cassiopeia/src/format/mod.rs
index 814c08656dbe..89f3a6ccb466 100644
--- a/apps/cassiopeia/src/format/mod.rs
+++ b/apps/cassiopeia/src/format/mod.rs
@@ -1,18 +1,22 @@
 //! cassiopeia file format
 
-mod ir;
+mod gen;
+pub(crate) mod ir;
 mod lexer;
 mod parser;
 
-pub(crate) use ir::{IrItem, IrStream, IrType, MakeIr};
 pub(crate) use lexer::{LineLexer, LineToken, Token};
 pub(crate) use parser::LineCfg;
 
 use crate::TimeFile;
-use std::{fs::File, io::Read};
+use ir::{IrItem, IrStream};
+use std::{
+    fs::{File, OpenOptions},
+    io::{Read, Write},
+};
 
 #[derive(Default)]
-pub struct ParseOutput {
+pub(crate) struct ParseOutput {
     pub(crate) ir: IrStream,
     pub(crate) tf: TimeFile,
 }
@@ -27,7 +31,7 @@ impl ParseOutput {
 
 /// Load a file from disk and parse it into a
 /// [`TimeFile`](crate::TimeFile)
-pub fn load_file(path: &str) -> Option<ParseOutput> {
+pub(crate) fn load_file(path: &str) -> Option<ParseOutput> {
     let mut f = File::open(path).ok()?;
     let mut content = String::new();
     f.read_to_string(&mut content).ok()?;
@@ -45,3 +49,19 @@ pub fn load_file(path: &str) -> Option<ParseOutput> {
         .fold(ParseOutput::default(), |output, ir| output.append(ir)),
     )
 }
+
+/// Write a file with the updated IR stream
+pub(crate) fn write_file(path: &str, ir: &mut IrStream) -> Option<()> {
+    ir::update_header(ir);
+    let mut lines = ir.into_iter().map(|ir| gen::line(ir)).collect::<Vec<_>>();
+    lines.insert(0, gen::head_comment());
+
+    let mut f = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .truncate(true)
+        .open(path)
+        .ok()?;
+    f.write_all(lines.join("\n").as_bytes()).ok()?;
+    Some(())
+}