1 files changed, 168 insertions, 0 deletions
diff --git a/src/watch/state.rs b/src/watch/state.rs
new file mode 100644
index 0000000..c0f6c53
--- /dev/null
+++ b/src/watch/state.rs
@@ -0,0 +1,168 @@
+use anyhow::Result;
+use crossterm::{
+    style::Stylize,
+    terminal::{size, Clear, ClearType},
+    ExecutableCommand,
+};
+use std::io::{self, StdoutLock, Write};
+
+use crate::{
+    app_state::{AppState, ExercisesProgress},
+    progress_bar::progress_bar,
+};
+
+pub struct WatchState<'a> {
+    writer: StdoutLock<'a>,
+    app_state: &'a mut AppState,
+    stdout: Option<Vec<u8>>,
+    stderr: Option<Vec<u8>>,
+    show_hint: bool,
+    show_done: bool,
+    manual_run: bool,
+}
+
+impl<'a> WatchState<'a> {
+    pub fn new(app_state: &'a mut AppState, manual_run: bool) -> Self {
+        let writer = io::stdout().lock();
+
+        Self {
+            writer,
+            app_state,
+            stdout: None,
+            stderr: None,
+            show_hint: false,
+            show_done: false,
+            manual_run,
+        }
+    }
+
+    #[inline]
+    pub fn into_writer(self) -> StdoutLock<'a> {
+        self.writer
+    }
+
+    pub fn run_current_exercise(&mut self) -> Result<()> {
+        self.show_hint = false;
+
+        let output = self.app_state.current_exercise().run()?;
+        self.stdout = Some(output.stdout);
+
+        if output.status.success() {
+            self.stderr = None;
+            self.show_done = true;
+        } else {
+            self.app_state
+                .set_pending(self.app_state.current_exercise_ind())?;
+
+            self.stderr = Some(output.stderr);
+            self.show_done = false;
+        }
+
+        self.render()
+    }
+
+    pub fn run_exercise_with_ind(&mut self, exercise_ind: usize) -> Result<()> {
+        self.app_state.set_current_exercise_ind(exercise_ind)?;
+        self.run_current_exercise()
+    }
+
+    pub fn next_exercise(&mut self) -> Result<ExercisesProgress> {
+        if !self.show_done {
+            self.writer
+                .write_all(b"The current exercise isn't done yet\n")?;
+            self.show_prompt()?;
+            return Ok(ExercisesProgress::Pending);
+        }
+
+        self.app_state.done_current_exercise(&mut self.writer)
+    }
+
+    fn show_prompt(&mut self) -> io::Result<()> {
+        self.writer.write_all(b"\n")?;
+
+        if self.manual_run {
+            self.writer.write_fmt(format_args!("{}un/", 'r'.bold()))?;
+        }
+
+        if self.show_done {
+            self.writer.write_fmt(format_args!("{}ext/", 'n'.bold()))?;
+        }
+
+        if !self.show_hint {
+            self.writer.write_fmt(format_args!("{}int/", 'h'.bold()))?;
+        }
+
+        self.writer
+            .write_fmt(format_args!("{}ist/{}uit? ", 'l'.bold(), 'q'.bold()))?;
+
+        self.writer.flush()
+    }
+
+    pub fn render(&mut self) -> Result<()> {
+        // Prevent having the first line shifted.
+        self.writer.write_all(b"\n")?;
+
+        self.writer.execute(Clear(ClearType::All))?;
+
+        if let Some(stdout) = &self.stdout {
+            self.writer.write_all(stdout)?;
+            self.writer.write_all(b"\n")?;
+        }
+
+        if let Some(stderr) = &self.stderr {
+            self.writer.write_all(stderr)?;
+            self.writer.write_all(b"\n")?;
+        }
+
+        self.writer.write_all(b"\n")?;
+
+        if self.show_hint {
+            self.writer.write_fmt(format_args!(
+                "{}\n{}\n\n",
+                "Hint".bold().cyan().underlined(),
+                self.app_state.current_exercise().hint,
+            ))?;
+        }
+
+        if self.show_done {
+            self.writer.write_fmt(format_args!(
+                "{}\n\n",
+                "Exercise done ✓
+When you are done experimenting, enter `n` or `next` to go to the next exercise 🦀"
+                    .bold()
+                    .green(),
+            ))?;
+        }
+
+        let line_width = size()?.0;
+        let progress_bar = progress_bar(
+            self.app_state.n_done(),
+            self.app_state.exercises().len() as u16,
+            line_width,
+        )?;
+        self.writer.write_fmt(format_args!(
+            "{progress_bar}Current exercise: {}\n",
+            self.app_state.current_exercise().terminal_link(),
+        ))?;
+
+        self.show_prompt()?;
+
+        Ok(())
+    }
+
+    pub fn show_hint(&mut self) -> Result<()> {
+        self.show_hint = true;
+        self.render()
+    }
+
+    pub fn handle_invalid_cmd(&mut self, cmd: &str) -> io::Result<()> {
+        self.writer.write_all(b"Invalid command: ")?;
+        self.writer.write_all(cmd.as_bytes())?;
+        if cmd.len() > 1 {
+            self.writer
+                .write_all(b" (confusing input can occur after resizing the terminal)")?;
+        }
+        self.writer.write_all(b"\n")?;
+        self.show_prompt()
+    }
+}