rialo-build-lib 0.11.2

// Copyright (c) Subzero Labs, Inc.
// SPDX-License-Identifier: Apache-2.0

//! Source code building support for toolchains
//!
//! This module provides infrastructure for building toolchains from source,
//! particularly the Rialo Rust toolchain from the rust-lang/rust repository.

use std::path::PathBuf;

use anyhow::{Context, Result};

use super::{
    get_platform, get_toolchain_root,
    rialo_rust::{RUST_COMMIT_HASH, RUST_NIGHTLY_VERSION},
    RialoRustToolchain,
};

/// Configuration for building a toolchain from source
#[derive(Debug, Clone)]
pub struct SourceBuildConfig {
    /// URL to the source repository
    pub source_url: String,
    /// Git commit hash to checkout
    pub commit_hash: String,
    /// Path to patch files to apply
    pub patch_files: Vec<PathBuf>,
    /// Build system configuration
    pub build_config: BuildSystemConfig,
}

impl Default for SourceBuildConfig {
    fn default() -> Self {
        Self {
            source_url: "https://github.com/rust-lang/rust".to_string(),
            commit_hash: RUST_COMMIT_HASH.to_string(),
            patch_files: Vec::new(),
            build_config: BuildSystemConfig::default(),
        }
    }
}

/// Build system configuration
#[derive(Debug, Clone)]
pub enum BuildSystemConfig {
    /// Rust bootstrap build system (x.py)
    RustBootstrap {
        /// Build profile (e.g., "compiler")
        profile: String,
        /// Target platforms to build for
        targets: Vec<String>,
        /// Whether to build extended tools
        extended: bool,
        /// Additional tools to build
        tools: Vec<String>,
        /// Build stage (typically 2 for compiler)
        build_stage: u32,
    },
}

impl Default for BuildSystemConfig {
    fn default() -> Self {
        let platform = get_platform().unwrap_or_else(|_| "unknown".to_string());
        Self::RustBootstrap {
            profile: "compiler".to_string(),
            targets: vec![platform, "riscv64emac-solana-solana".to_string()],
            extended: true,
            tools: vec!["cargo".to_string()],
            build_stage: 0, // Don't set build-stage, let bootstrap decide
        }
    }
}

/// Trait for toolchains that can be built from source
pub trait SourceBuildable {
    /// Check if building from source is supported
    fn can_build_from_source(&self) -> bool;

    /// Get the source build configuration
    fn get_source_config(&self) -> Result<SourceBuildConfig>;

    /// Build the toolchain from source
    fn build_from_source(&self, config: &SourceBuildConfig) -> Result<()>;
}

/// Rust source builder for the Rialo toolchain
pub struct RustSourceBuilder {
    /// Directory where Rust source will be cloned
    source_dir: PathBuf,
    /// Directory where toolchain will be installed
    install_dir: PathBuf,
    /// Build configuration
    config: SourceBuildConfig,
}

impl RustSourceBuilder {
    /// Create a new Rust source builder
    pub fn new(install_dir: PathBuf) -> Result<Self> {
        let toolchain_root = get_toolchain_root()?;
        let source_dir = toolchain_root.parent().unwrap().join("rust-src/rust");

        Ok(Self {
            source_dir,
            install_dir,
            config: SourceBuildConfig::default(),
        })
    }

    /// Create a new builder with custom configuration
    pub fn with_config(install_dir: PathBuf, config: SourceBuildConfig) -> Result<Self> {
        let toolchain_root = get_toolchain_root()?;
        let source_dir = toolchain_root.parent().unwrap().join("rust-src/rust");

        Ok(Self {
            source_dir,
            install_dir,
            config,
        })
    }

    /// Clone the Rust source repository
    pub fn clone_source(&self) -> Result<()> {
        if self.source_dir.exists() {
            println!(
                "Rust source directory already exists at {}",
                self.source_dir.display()
            );
            println!("Checking out commit {}...", self.config.commit_hash);

            // Verify we're on the right commit
            let output = std::process::Command::new("git")
                .current_dir(&self.source_dir)
                .args(["rev-parse", "HEAD"])
                .output()
                .context("Failed to get current git commit")?;

            let current_commit = String::from_utf8_lossy(&output.stdout).trim().to_string();

            if current_commit == self.config.commit_hash {
                println!("✅ Already on correct commit");
                return Ok(());
            }

            // Fetch and checkout the correct commit
            println!("Fetching latest changes...");
            std::process::Command::new("git")
                .current_dir(&self.source_dir)
                .args(["fetch"])
                .status()
                .context("Failed to fetch git changes")?;

            std::process::Command::new("git")
                .current_dir(&self.source_dir)
                .args(["checkout", &self.config.commit_hash])
                .status()
                .context("Failed to checkout commit")?;

            println!("✅ Checked out commit {}", self.config.commit_hash);
            return Ok(());
        }

        println!("Cloning Rust repository from {}...", self.config.source_url);
        println!("This may take several minutes...");

        // Create parent directory
        if let Some(parent) = self.source_dir.parent() {
            std::fs::create_dir_all(parent)
                .with_context(|| format!("Failed to create directory {}", parent.display()))?;
        }

        // Clone the repository
        let source_dir_str = self.source_dir.to_str().ok_or_else(|| {
            anyhow::anyhow!(
                "Invalid source directory path: {}",
                self.source_dir.display()
            )
        })?;

        let status = std::process::Command::new("git")
            .args(["clone", &self.config.source_url, source_dir_str])
            .status()
            .context("Failed to clone Rust repository")?;

        if !status.success() {
            return Err(anyhow::anyhow!("Git clone failed"));
        }

        // Checkout specific commit
        println!("Checking out commit {}...", self.config.commit_hash);
        let status = std::process::Command::new("git")
            .current_dir(&self.source_dir)
            .args(["checkout", &self.config.commit_hash])
            .status()
            .context("Failed to checkout commit")?;

        if !status.success() {
            return Err(anyhow::anyhow!("Git checkout failed"));
        }

        println!("✅ Rust source ready at {}", self.source_dir.display());
        Ok(())
    }

    /// Apply patches to the Rust source
    pub fn apply_patches(&self) -> Result<()> {
        if self.config.patch_files.is_empty() {
            println!("No patches to apply");
            return Ok(());
        }

        println!("Applying {} patches...", self.config.patch_files.len());

        // First, check if we need to clean any existing patch artifacts
        let target_file = self
            .source_dir
            .join("compiler/rustc_target/src/spec/targets/riscv64emac_solana_solana.rs");

        for patch_file in &self.config.patch_files {
            println!("Applying patch: {}", patch_file.display());

            // Check if patch can be applied
            let patch_path_str = patch_file.to_str().ok_or_else(|| {
                anyhow::anyhow!("Invalid patch file path: {}", patch_file.display())
            })?;

            let check_status = std::process::Command::new("git")
                .current_dir(&self.source_dir)
                .args(["apply", "--check", patch_path_str])
                .output();

            match check_status {
                Ok(output) if output.status.success() => {
                    // Patch can be applied cleanly
                    let apply_status = std::process::Command::new("git")
                        .current_dir(&self.source_dir)
                        .args(["apply", patch_path_str])
                        .status()
                        .context("Failed to apply patch")?;

                    if !apply_status.success() {
                        return Err(anyhow::anyhow!(
                            "Failed to apply patch {}",
                            patch_file.display()
                        ));
                    }

                    println!("  ✅ Patch applied successfully");
                }
                Ok(_) => {
                    // Patch cannot be applied - check if it's already applied
                    if target_file.exists() {
                        println!("  ⚠ Patch appears to be already applied");
                        continue;
                    } else {
                        // Patch failed and target doesn't exist - try to reset and apply
                        println!("  ⚠ Patch conflicts detected, resetting to clean state...");

                        // Reset to HEAD to clean any partial patch application
                        let reset_status = std::process::Command::new("git")
                            .current_dir(&self.source_dir)
                            .args(["reset", "--hard", "HEAD"])
                            .status()
                            .context("Failed to reset git repository")?;

                        if !reset_status.success() {
                            return Err(anyhow::anyhow!(
                                "Failed to reset repository to clean state"
                            ));
                        }

                        // Try applying again
                        let apply_status = std::process::Command::new("git")
                            .current_dir(&self.source_dir)
                            .args(["apply", patch_path_str])
                            .status()
                            .context("Failed to apply patch after reset")?;

                        if !apply_status.success() {
                            return Err(anyhow::anyhow!(
                                "Failed to apply patch {} even after reset",
                                patch_file.display()
                            ));
                        }

                        println!("  ✅ Patch applied successfully after reset");
                    }
                }
                Err(e) => {
                    return Err(anyhow::anyhow!("Failed to check patch: {}", e));
                }
            }
        }

        println!("✅ All patches applied");
        Ok(())
    }

    /// Create config.toml for the Rust build
    pub fn create_config_toml(&self) -> Result<()> {
        println!("Creating config.toml...");

        let BuildSystemConfig::RustBootstrap {
            profile,
            targets,
            extended,
            tools,
            build_stage: _,
        } = &self.config.build_config;

        // Create sysconfdir
        let sysconfdir = self.install_dir.join("sysconfdir");
        std::fs::create_dir_all(&sysconfdir)
            .with_context(|| format!("Failed to create sysconfdir {}", sysconfdir.display()))?;

        // Format targets
        let targets_str = targets
            .iter()
            .map(|t| format!("\"{}\"", t))
            .collect::<Vec<_>>()
            .join(", ");

        // Format tools
        let tools_str = tools
            .iter()
            .map(|t| format!("\"{}\"", t))
            .collect::<Vec<_>>()
            .join(", ");

        // Detect CI environment and set appropriate build stage
        // CI requires stage 2 for safety, local builds can use stage 1 for speed
        let is_ci = std::env::var("CI").is_ok()
            || std::env::var("GITHUB_ACTIONS").is_ok()
            || std::env::var("GITLAB_CI").is_ok()
            || std::env::var("CIRCLECI").is_ok();

        let build_stage = if is_ci {
            println!("CI environment detected: using build-stage = 2");
            2
        } else {
            println!("Local environment: using build-stage = 1 for faster builds");
            1
        };

        // Determine compiler paths for LLVM build
        let (cc_path, cxx_path) = if cfg!(target_os = "macos") {
            // Use Xcode clang on macOS
            ("/usr/bin/clang", "/usr/bin/clang++")
        } else {
            // Linux: prefer clang, fallback to gcc
            if which::which("clang").is_ok() {
                ("clang", "clang++")
            } else {
                ("gcc", "g++")
            }
        };

        // Disable CI LLVM downloads (old commits get deleted, causing 404 errors)
        // Use static linking to simplify build and avoid installation path issues
        let config_content = format!(
            r#"profile = "{profile}"
change-id = 137215

[build]
host = ["{host}"]
target = [{targets_str}]
docs = false
extended = {extended}
tools = [{tools_str}]
build-stage = {build_stage}

[install]
prefix = "{install_prefix}"
sysconfdir = "{sysconfdir}"

[llvm]
download-ci-llvm = false
link-shared = false
ccache = false

[llvm.build-config]
CMAKE_BUILD_TYPE = "Release"
CMAKE_C_COMPILER = "{cc_path}"
CMAKE_CXX_COMPILER = "{cxx_path}"
CMAKE_ASM_COMPILER = "{cc_path}"

[rust]
lld = true
incremental = true
debug-assertions = false
"#,
            profile = profile,
            host = get_platform()?,
            targets_str = targets_str,
            extended = extended,
            tools_str = tools_str,
            build_stage = build_stage,
            cc_path = cc_path,
            cxx_path = cxx_path,
            install_prefix = self.install_dir.display(),
            sysconfdir = sysconfdir.display(),
        );

        let config_path = self.source_dir.join("config.toml");
        std::fs::write(&config_path, config_content)
            .with_context(|| format!("Failed to write config.toml to {}", config_path.display()))?;

        println!("✅ config.toml created");
        Ok(())
    }

    /// Build the Rust toolchain
    pub fn build(&self) -> Result<()> {
        use std::io::Write;

        println!("Building Rust toolchain...");
        println!("⚠️  This will take 30-60 minutes depending on your system");
        println!("Build progress: stage0 → stage1 → stage2");
        println!();
        let _ = std::io::stdout().flush(); // Ensure output is visible

        // Set up environment variables
        let mut cmd = std::process::Command::new("./x.py");
        cmd.current_dir(&self.source_dir);
        cmd.arg("build");

        // Build stage and compiler paths are configured in config.toml
        // Set compiler flags to suppress pointer type warnings
        cmd.env("CFLAGS", "-Wno-error=incompatible-pointer-types");
        cmd.env("CXXFLAGS", "-Wno-error=incompatible-pointer-types");

        println!("Starting build...");
        let _ = std::io::stdout().flush();

        let status = cmd.status().context("Failed to start build")?;

        if !status.success() {
            eprintln!("❌ Build failed!");
            let _ = std::io::stderr().flush();
            return Err(anyhow::anyhow!(
                "Build failed with exit code: {:?}\nCheck the output above for errors.\nSource directory: {}",
                status.code(),
                self.source_dir.display()
            ));
        }

        println!("✅ Build completed successfully");
        let _ = std::io::stdout().flush();
        Ok(())
    }

    /// Install the built toolchain
    pub fn install(&self) -> Result<()> {
        use std::io::Write;

        println!("Installing toolchain to {}...", self.install_dir.display());
        println!("This will copy the built toolchain to the install directory...");
        let _ = std::io::stdout().flush();

        let status = std::process::Command::new("./x.py")
            .current_dir(&self.source_dir)
            .arg("install")
            .status()
            .context("Failed to start install")?;

        if !status.success() {
            eprintln!("❌ Installation failed!");
            let _ = std::io::stderr().flush();
            return Err(anyhow::anyhow!(
                "Installation failed with exit code: {:?}\nCheck the output above for errors.\nInstall directory: {}",
                status.code(),
                self.install_dir.display()
            ));
        }

        println!("✅ Toolchain installed to {}", self.install_dir.display());
        let _ = std::io::stdout().flush();
        Ok(())
    }

    /// Complete build process: clone, patch, configure, build, install
    pub fn build_complete(&self) -> Result<()> {
        self.clone_source()?;
        self.apply_patches()?;
        self.create_config_toml()?;
        self.build()?;
        self.install()?;
        Ok(())
    }
}

impl SourceBuildable for RialoRustToolchain {
    fn can_build_from_source(&self) -> bool {
        // Check if required tools are available
        which::which("git").is_ok()
            && which::which("python3").is_ok()
            && which::which("cmake").is_ok()
            && which::which("rustup").is_ok()
    }

    fn get_source_config(&self) -> Result<SourceBuildConfig> {
        // Write patch to the toolchain install directory
        let patch_dir = self.config.install_path.join("patches");
        std::fs::create_dir_all(&patch_dir)
            .with_context(|| format!("Failed to create patch directory {}", patch_dir.display()))?;

        let patch_path = Self::write_patch_file(&patch_dir)?;

        let config = SourceBuildConfig {
            patch_files: vec![patch_path],
            ..Default::default()
        };

        Ok(config)
    }

    fn build_from_source(&self, config: &SourceBuildConfig) -> Result<()> {
        Self::check_rustup()?;
        self.with_install_lock(|toolchain| toolchain.build_from_source_unlocked(config))
    }
}

impl RialoRustToolchain {
    fn build_from_source_unlocked(&self, config: &SourceBuildConfig) -> Result<()> {
        println!("Building Rialo Rust toolchain from source...");
        println!("Version: {}", RUST_NIGHTLY_VERSION);
        println!("Commit: {}", RUST_COMMIT_HASH);
        println!();

        // Check prerequisites
        if !self.can_build_from_source() {
            return Err(anyhow::anyhow!(
                "Missing required tools for source build. Please ensure git, python3, cmake, and rustup are installed."
            ));
        }

        // Create source builder
        let builder =
            RustSourceBuilder::with_config(self.config.install_path.clone(), config.clone())?;

        // Build
        builder.build_complete()?;

        // Register with rustup
        self.register_with_rustup_unlocked()?;

        println!();
        println!("✅ Rialo Rust toolchain built and installed successfully");
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_source_build_config_default() {
        let config = SourceBuildConfig::default();
        assert_eq!(config.source_url, "https://github.com/rust-lang/rust");
        assert_eq!(config.commit_hash, RUST_COMMIT_HASH);
    }

    #[test]
    fn test_build_system_config_default() {
        let config = BuildSystemConfig::default();
        match config {
            BuildSystemConfig::RustBootstrap {
                profile,
                targets,
                extended,
                tools,
                build_stage,
            } => {
                assert_eq!(profile, "compiler");
                assert!(targets.contains(&"riscv64emac-solana-solana".to_string()));
                assert!(extended);
                assert!(tools.contains(&"cargo".to_string()));
                assert_eq!(build_stage, 0); // 0 = let bootstrap decide
            }
        }
    }
}