From cdf81b610d9fcd922ad2598fb12cc0d62cbd542d Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sun, 3 Sep 2023 14:00:56 -0700
Subject: [PATCH] terminal: mark prompt continuation lines, end prompt clear at
 first prompt

---
 src/terminal/Screen.zig   |  7 ++++---
 src/terminal/Terminal.zig | 17 +++++++++++++----
 src/terminal/stream.zig   | 13 +++++++------
 src/termio/Exec.zig       |  5 +++++
 4 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/src/terminal/Screen.zig b/src/terminal/Screen.zig
index 532bb352e..98b6edc4a 100644
--- a/src/terminal/Screen.zig
+++ b/src/terminal/Screen.zig
@@ -155,13 +155,14 @@ pub const RowHeader = struct {
         /// This is a prompt line, meaning it only contains the shell prompt.
         /// For poorly behaving shells, this may also be the input.
         prompt = 1,
+        prompt_continuation = 2,
 
         /// This line contains the input area. We don't currently track
         /// where this actually is in the line, so we just assume it is somewhere.
-        input = 2,
+        input = 3,
 
         /// This line is the start of command output.
-        command = 3,
+        command = 4,
     };
 };
 
@@ -1762,7 +1763,7 @@ fn jumpPrompt(self: *Screen, delta: isize) bool {
     while (y >= 0 and y <= max_y and delta_rem > 0) : (y += step) {
         const row = self.getRow(.{ .screen = @intCast(y) });
         switch (row.getSemanticPrompt()) {
-            .prompt, .input => delta_rem -= 1,
+            .prompt, .prompt_continuation, .input => delta_rem -= 1,
             .command, .unknown => {},
         }
     }
diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 025167d74..bd32dbb83 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -40,6 +40,7 @@ pub const ScreenType = enum {
 /// See: https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md
 pub const SemanticPrompt = enum {
     prompt,
+    prompt_continuation,
     input,
     command,
 };
@@ -361,12 +362,18 @@ fn clearPromptForResize(self: *Terminal) void {
             const real_y = self.screen.cursor.y - y;
             const row = self.screen.getRow(.{ .active = real_y });
             switch (row.getSemanticPrompt()) {
-                // If we're at a prompt or input area, then we are at a prompt.
+                // We are at a prompt but we're not at the start of the prompt.
                 // We mark our found value and continue because the prompt
                 // may be multi-line.
-                .prompt,
-                .input,
-                => found = real_y,
+                .input => found = real_y,
+
+                // If we find the prompt then we're done. We are also done
+                // if we find any prompt continuation, because the shells
+                // that send this currently (zsh) cannot redraw every line.
+                .prompt, .prompt_continuation => {
+                    found = real_y;
+                    break;
+                },
 
                 // If we have command output, then we're most certainly not
                 // at a prompt. Break out of the loop.
@@ -1535,6 +1542,7 @@ pub fn markSemanticPrompt(self: *Terminal, p: SemanticPrompt) void {
     const row = self.screen.getRow(.{ .active = self.screen.cursor.y });
     row.setSemanticPrompt(switch (p) {
         .prompt => .prompt,
+        .prompt_continuation => .prompt_continuation,
         .input => .input,
         .command => .command,
     });
@@ -1557,6 +1565,7 @@ pub fn cursorIsAtPrompt(self: *Terminal) bool {
         switch (row.getSemanticPrompt()) {
             // If we're at a prompt or input area, then we are at a prompt.
             .prompt,
+            .prompt_continuation,
             .input,
             => return true,
 
diff --git a/src/terminal/stream.zig b/src/terminal/stream.zig
index 57dc801b7..c922df8f4 100644
--- a/src/terminal/stream.zig
+++ b/src/terminal/stream.zig
@@ -53,10 +53,10 @@ pub fn Stream(comptime Handler: type) type {
             // log.debug("char: {c}", .{c});
             const actions = self.parser.next(c);
             for (actions) |action_opt| {
-                // if (action_opt) |action| {
-                //     if (action != .print)
-                //         log.info("action: {}", .{action});
-                // }
+                if (action_opt) |action| {
+                    if (action != .print and action == .osc_dispatch)
+                        log.info("action: {}", .{action});
+                }
                 switch (action_opt orelse continue) {
                     .print => |p| if (@hasDecl(T, "print")) try self.handler.print(p),
                     .execute => |code| try self.execute(code),
@@ -802,8 +802,9 @@ pub fn Stream(comptime Handler: type) type {
                 },
 
                 .prompt_start => |v| {
-                    if (@hasDecl(T, "promptStart")) {
-                        try self.handler.promptStart(v.aid, v.redraw);
+                    if (@hasDecl(T, "promptStart")) switch (v.kind) {
+                        .primary, .right => try self.handler.promptStart(v.aid, v.redraw),
+                        .continuation => try self.handler.promptContinuation(v.aid),
                     } else log.warn("unimplemented OSC callback: {}", .{cmd});
                 },
 
diff --git a/src/termio/Exec.zig b/src/termio/Exec.zig
index 021e58fe8..175e7fa0d 100644
--- a/src/termio/Exec.zig
+++ b/src/termio/Exec.zig
@@ -1623,6 +1623,11 @@ const StreamHandler = struct {
         self.terminal.flags.shell_redraws_prompt = redraw;
     }
 
+    pub fn promptContinuation(self: *StreamHandler, aid: ?[]const u8) !void {
+        _ = aid;
+        self.terminal.markSemanticPrompt(.prompt_continuation);
+    }
+
     pub fn promptEnd(self: *StreamHandler) !void {
         self.terminal.markSemanticPrompt(.input);
     }