From 6408ffa803f329e521c06d1fa57babf20885c2aa Mon Sep 17 00:00:00 2001
From: Antonio Cuni <anto.cuni@gmail.com>
Date: Fri, 29 Sep 2023 11:04:45 +0200
Subject: [PATCH] a very hacky and very very tentative implementation sketchy
 implementation of the py-terminal plugin

---
 pyscript.core/src/plugins/pyterminal.js     | 109 ++++++++++++++++++++
 pyscript.core/test/pyterminal.html          |  31 ++++++
 pyscript.core/types/plugins.d.ts            |   1 +
 pyscript.core/types/plugins/pyterminal.d.ts |   1 +
 4 files changed, 142 insertions(+)
 create mode 100644 pyscript.core/src/plugins/pyterminal.js
 create mode 100644 pyscript.core/test/pyterminal.html
 create mode 100644 pyscript.core/types/plugins/pyterminal.d.ts

diff --git a/pyscript.core/src/plugins/pyterminal.js b/pyscript.core/src/plugins/pyterminal.js
new file mode 100644
index 00000000..70773ebe
--- /dev/null
+++ b/pyscript.core/src/plugins/pyterminal.js
@@ -0,0 +1,109 @@
+// PyScript py-terminal plugin
+import { hooks } from "../core.js";
+
+// XXX TODO:
+// 1. these imports should be lazy?
+// 2. would be nice to automatically add xterm.css on demand
+import { Terminal } from 'https://cdn.jsdelivr.net/npm/xterm@5.3.0/+esm'
+import { Readline } from 'https://cdn.jsdelivr.net/npm/xterm-readline@1.1.1/+esm'
+const makePyTerminal = () => {
+    const element = document.querySelector('py-terminal');
+    if (element === null) {
+        return false;
+    }
+
+    const term = new Terminal({
+        theme: {
+            background: "#191A19",
+            foreground: "#F5F2E7",
+        },
+        cursorBlink: true,
+        cursorStyle: "block",
+        rows: 50
+    });
+
+    const rl = new Readline();
+    term.loadAddon(rl);
+    term.open(element);
+    term.focus();
+
+    async function readline(prompt) {
+        //console.log("readline", prompt);
+        const line = await rl.read(prompt);
+        return line;
+    }
+
+    async function write(line) {
+        //console.log("write", line);
+        rl.write(line);
+    }
+
+    console.log("PyTerminal made?");
+    return { term, readline, write };
+}
+
+// this is ONLY for non-workers, correct?
+// TODO: how to make it working for workers?
+hooks.onInterpreterReady.add(function override(pyScript) {
+    console.log("hello onInterpreterReady");
+    const t = makePyTerminal();
+    if (!t) {
+        console.log("<py-terminal> not found, nothing to do");
+        return;
+    }
+    const { stdout, stderr } = pyScript.io;
+
+    pyScript.io.stdout = (s, ...rest) => {
+        // XXX: the + "\n" is conceptually wrong.
+        // We probably need to configure pyodide's stdout as "raw mode"
+        // instead of "batched mode":
+        // https://pyodide.org/en/stable/usage/streams.html#a-raw-handler
+        t.write(s + "\n");
+        stdout(s, ...rest);
+    }
+
+    pyScript.io.stderr = (s, ...rest) => {
+        t.write(s + "\n"); // see above for the "\n"
+        stderr(s, ...rest);
+    }
+});
+
+
+// this is mostly pseudo-code for what it *should* happen for the workers case
+/*
+addEventListener("py:ready", (event) => {
+    console.log("hello py:ready");
+    if (!event.detail.worker) {
+        return;
+    }
+
+    const t = makePyTerminal();
+    if (!t) {
+        console.log("<py-terminal> not found, nothing to do");
+        return;
+    }
+
+    const xworker = event.target.xworker;
+
+    xworker.sync.pyterminal_readline = t.readline;
+    xworker.sync.pyterminal_write = t.write;
+
+    // XXX: I know that the following lines don't work, but this is more or
+    // lesswhat I would like to happen
+    pyScript.io.stdout = (s, ...rest) => {
+        // this is JS code, and we cannot send arbitrary JS code from the main
+        // to the worker. So maybe a solution is to hardcode this logic
+        // directly inside the worker code?
+        xworker.sync.pyterminal_write(s);
+    }
+    pyScript.io.stderr = (s, ...rest) => {
+        xworker.sync.pyterminal_write(s);
+    }
+    something.runPython(`
+        import builtins
+        import pyscript
+        builtins.input = sync.pyterminal_readline
+    `)
+
+});
+*/
diff --git a/pyscript.core/test/pyterminal.html b/pyscript.core/test/pyterminal.html
new file mode 100644
index 00000000..769bcb6c
--- /dev/null
+++ b/pyscript.core/test/pyterminal.html
@@ -0,0 +1,31 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+        <title>PyScript Next</title>
+        <script>
+            addEventListener("py:ready", console.log);
+        </script>
+        <link rel="stylesheet" href="../dist/core.css">
+        <script type="module" src="../dist/core.js"></script>
+
+        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/xterm@5.2.1/css/xterm.min.css">
+
+    </head>
+    <body>
+        <script type="py">
+            import sys
+            from pyscript import display
+            display("Hello", "PyScript Next", append=False)
+            print("this should go to the terminal")
+            print("another line")
+
+            # XXX we have a problem with the error plugin: this line should
+            # just go to the terminal, NOT to the red box in the DOM
+            print("this goes to stderr", file=sys.stderr)
+        </script>
+
+        <py-terminal></py-terminal>
+    </body>
+</html>
diff --git a/pyscript.core/types/plugins.d.ts b/pyscript.core/types/plugins.d.ts
index 1afe1308..176dc5cb 100644
--- a/pyscript.core/types/plugins.d.ts
+++ b/pyscript.core/types/plugins.d.ts
@@ -1,4 +1,5 @@
 declare namespace _default {
     function error(): Promise<typeof import("./plugins/error.js")>;
+    function pyterminal(): Promise<typeof import("./plugins/pyterminal.js")>;
 }
 export default _default;
diff --git a/pyscript.core/types/plugins/pyterminal.d.ts b/pyscript.core/types/plugins/pyterminal.d.ts
new file mode 100644
index 00000000..cb0ff5c3
--- /dev/null
+++ b/pyscript.core/types/plugins/pyterminal.d.ts
@@ -0,0 +1 @@
+export {};