add gnuplot plotting

.gitignore

@@ -2,3 +2,4 @@
 /.vscode
 /*.csv
 /*.nscim
+/plot.png

src/app/app.rs

@@ -42,7 +42,7 @@ impl Widget for &App {
         let (x_max, y_max) = self.screen.how_many_cells_fit_in(&area, &self.vars);
 
         let is_selected = |x: usize, y: usize| -> bool {
-            if let Mode::Visual((mut x1, mut y1)) = self.mode {
+            if let Mode::Visual((mut x1, mut y1)) | Mode::VisualCmd((mut x1, mut y1), _)= self.mode {
                 let (mut x2, mut y2) = self.grid.cursor();
                 x1 += 1;
                 y1 += 1;
@@ -80,10 +80,6 @@ impl Widget for &App {
                     y_idx = y as usize - 1 + self.screen.scroll_y();
                 }
 
-                if is_selected(x.into(), y.into()) {
-                    style = style.fg(Color::LightMagenta).bg(Color::Blue);
-                }
-
                 const ORANGE1: Color = Color::Rgb(200, 160, 0);
                 const ORANGE2: Color = Color::Rgb(180, 130, 0);
 
@@ -171,6 +167,10 @@ impl Widget for &App {
                             }
                             None => should_render = false,
                         }
+
+                        if is_selected(x.into(), y.into()) {
+                            style = style.bg(Color::Blue);
+                        }
                         if (x_idx, y_idx) == self.grid.cursor() {
                             should_render = true;
                             style = Style::new().fg(Color::Black).bg(Color::White);

src/app/mode.rs

@@ -1,5 +1,8 @@
 use std::{
-    cmp::{max, min}, fmt::Display, fs, path::PathBuf
+    cmp::{max, min},
+    fmt::Display,
+    fs,
+    path::PathBuf, process::Command,
 };
 
 use ratatui::{
@@ -12,7 +15,7 @@ use crate::app::{
     app::App,
     error_msg::StatusMessage,
     logic::{
-        calc::{CSV_EXT, CUSTOM_EXT, LEN},
+        calc::{CSV_EXT, CUSTOM_EXT, Grid, LEN},
         cell::CellType,
     },
 };
@@ -152,8 +155,73 @@ impl Mode {
             if args.is_empty() {
                 return;
             }
+
+            // These values are going to be used in probably all
+            // the commands related to ranges, we will just write
+            // logic here first, once.
+            let (x1, y1) = pos;
+            let (x1, y1) = (*x1, *y1);
+            let (x2, y2) = app.grid.cursor();
+            let (low_x, hi_x) = if x1 < x2 { (x1, x2) } else { (x2, x1) };
+            let (low_y, hi_y) = if y1 < y2 { (y1, y2) } else { (y2, y1) };
+
+            let mut save_range = |to: &str| {
+                let mut g = Grid::new();
+                for (i, x) in (low_x..=hi_x).enumerate() {
+                    for (j, y) in (low_y..=hi_y).enumerate() {
+                        g.set_cell_raw((i, j), app.grid.get_cell_raw(x, y).clone());
+                    }
+                }
+                if let Err(_e) = g.save_to(to) {
+                    app.msg = StatusMessage::error("Failed to save file");
+                }
+            };
+
+            let get_project_name = || {
+                if let Some(file) = &app.file {
+                    if let Some(name) = file.file_name() {
+                        if let Some(name) = name.to_str() {
+                            return name;
+                        }
+                    }
+                }
+                return "unknown"
+            };
+
             match args[0] {
-                "foo" => {}
+                "export" => {
+                    if let Some(arg1) = args.get(1) {
+                        save_range(&arg1);
+                    } else {
+                        app.msg = StatusMessage::error("export <path.csv>")
+                    }
+                    app.mode = Mode::Normal
+                }
+                "plot" => {
+                    // Use gnuplot to plot the selected data.
+                    // * Temp data will be stored in /tmp/
+                    // * Output will either be plot.png or a name that you pass in
+                    let output_filename = if let Some(arg1) = args.get(1) {
+                        arg1
+                    } else {
+                        "plot.png"
+                    };
+
+                    save_range("/tmp/plot.csv");
+                    let plot = include_str!("../../template.gnuplot");
+                    let s = plot.replace("$FILE", "/tmp/plot.csv");
+                    let s = s.replace("$TITLE", get_project_name());
+                    let s = s.replace("$XLABEL", "hard-coded x");
+                    let s = s.replace("$YLABEL", "hard-coded y");
+                    let s = s.replace("$OUTPUT", "/tmp/output.png");
+                    let _ = fs::write("/tmp/plot.p", s);
+
+                    let _ = Command::new("gnuplot").arg("/tmp/plot.p").output();
+                    let _ = fs::copy("/tmp/output.png", output_filename);
+
+                    app.msg = StatusMessage::info("Wrote gnuplot data to /tmp");
+                    app.mode = Mode::Normal
+                }
                 _ => {}
             }
         }

template.gnuplot

@@ -1,10 +1,10 @@
-datafile = 'data.csv'
+datafile = '$FILE'
 set datafile separator ','
 
-set title 'Probably the filename'
+set title '$TITLE'
 set key autotitle columnhead
-set xlabel "x"
+set xlabel "$XLABEL"
-set ylabel "y"
+set ylabel "$YLABEL"
 
 set style line 1 linewidth 2 linecolor 1 pointtype 7 pointsize 1.5
 
@@ -12,6 +12,6 @@ set autoscale
 set grid
 
 set term png size 1280, 720
-set output 'output.png'
+set output '$OUTPUT'
 plot datafile using 1:2 with linespoints linestyle 1 
 replot