feat: setup windows system console output detection for dynamic console attach

src/platform/desktop.rs

@@ -6,6 +6,7 @@ use std::time::Duration;
 use crate::asset::Asset;
 use crate::error::{AssetError, PlatformError};
 use crate::platform::CommonPlatform;
+use tracing::{debug, info, warn};
 
 /// Desktop platform implementation.
 pub struct Platform;
@@ -24,6 +25,29 @@ impl CommonPlatform for Platform {
     }
 
     fn init_console(&self) -> Result<(), PlatformError> {
+        #[cfg(windows)]
+        {
+            use windows::Win32::System::Console::GetConsoleWindow;
+
+            // Check if we already have a console window
+            if unsafe { !GetConsoleWindow().0.is_null() } {
+                debug!("Already have a console window");
+                return Ok(());
+            } else {
+                debug!("No existing console window found");
+            }
+
+            if let Some(file_type) = Self::is_output_setup()? {
+                debug!(r#type = file_type, "Existing output detected");
+            } else {
+                debug!("No existing output detected");
+
+                // Try to attach to parent console for direct cargo run
+                Self::attach_to_parent_console()?;
+                info!("Successfully attached to parent console");
+            }
+        }
+
         Ok(())
     }
 
@@ -42,3 +66,102 @@ impl CommonPlatform for Platform {
         }
     }
 }
+
+#[cfg(windows)]
+impl Platform {
+    /// Check if the output stream has been setup by a parent process
+    fn is_output_setup() -> Result<Option<&'static str>, PlatformError> {
+        use windows::Win32::Storage::FileSystem::{
+            GetFileType, FILE_TYPE_CHAR, FILE_TYPE_DISK, FILE_TYPE_PIPE, FILE_TYPE_REMOTE, FILE_TYPE_UNKNOWN,
+        };
+
+        use windows_sys::Win32::{
+            Foundation::INVALID_HANDLE_VALUE,
+            System::Console::{GetStdHandle, STD_OUTPUT_HANDLE},
+        };
+
+        // Get the process's standard output handle, check if it's invalid
+        let handle = match unsafe { GetStdHandle(STD_OUTPUT_HANDLE) } {
+            INVALID_HANDLE_VALUE => {
+                return Err(PlatformError::ConsoleInit("Invalid handle".to_string()));
+            }
+            handle => handle,
+        };
+
+        // Identify the file type of the handle
+        let (well_known, file_type) = match unsafe {
+            use windows::Win32::Foundation::HANDLE;
+            GetFileType(HANDLE(handle))
+        } {
+            FILE_TYPE_PIPE => (true, "pipe"),
+            FILE_TYPE_CHAR => (true, "char"),
+            FILE_TYPE_DISK => (true, "disk"),
+            FILE_TYPE_UNKNOWN => (false, "unknown"),
+            FILE_TYPE_REMOTE => (false, "remote"),
+            unexpected => {
+                warn!("Unexpected file type: {unexpected:?}");
+                (false, "unknown")
+            }
+        };
+
+        debug!("File type: {file_type:?}, well known: {well_known}");
+
+        // If it's anything recognizable and valid, assume that a parent process has setup an output stream
+        Ok(well_known.then(|| file_type))
+    }
+
+    /// Try to attach to parent console
+    fn attach_to_parent_console() -> Result<(), PlatformError> {
+        use windows::{
+            core::PCSTR,
+            Win32::{
+                Foundation::{GENERIC_READ, GENERIC_WRITE},
+                Storage::FileSystem::{CreateFileA, FILE_FLAGS_AND_ATTRIBUTES, FILE_SHARE_READ, FILE_SHARE_WRITE, OPEN_EXISTING},
+                System::Console::{
+                    AttachConsole, FreeConsole, SetStdHandle, ATTACH_PARENT_PROCESS, STD_ERROR_HANDLE, STD_OUTPUT_HANDLE,
+                },
+            },
+        };
+
+        // Attach the process to the parent's console
+        unsafe { AttachConsole(ATTACH_PARENT_PROCESS) }
+            .map_err(|e| PlatformError::ConsoleInit(format!("Failed to attach to parent console: {:?}", e)))?;
+
+        let handle = unsafe {
+            let pcstr = PCSTR::from_raw("CONOUT$\0".as_ptr());
+            CreateFileA::<PCSTR>(
+                pcstr,
+                (GENERIC_READ | GENERIC_WRITE).0,
+                FILE_SHARE_READ | FILE_SHARE_WRITE,
+                None,
+                OPEN_EXISTING,
+                FILE_FLAGS_AND_ATTRIBUTES(0),
+                None,
+            )
+        }
+        .map_err(|e| PlatformError::ConsoleInit(format!("Failed to create console handle: {:?}", e)))?;
+
+        // Set the console's output and then error handles
+        if let Some(handle_error) = unsafe { SetStdHandle(STD_OUTPUT_HANDLE, handle) }
+            .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console output handle: {:?}", e)))
+            .and_then(|_| {
+                unsafe { SetStdHandle(STD_ERROR_HANDLE, handle) }
+                    .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console error handle: {:?}", e)))
+            })
+            .err()
+        {
+            // If either set handle call fails, free the console
+            unsafe { FreeConsole() }
+                // Free the console if the SetStdHandle calls fail
+                .map_err(|free_error| {
+                    PlatformError::ConsoleInit(format!(
+                        "Failed to free console after SetStdHandle failed: {free_error:?} ({handle_error:?})"
+                    ))
+                })
+                // And then return the original error if the FreeConsole call succeeds
+                .and(Err(handle_error))?;
+        }
+
+        Ok(())
+    }
+}