Update source files

crates/borders-core/build.rs

@@ -0,0 +1,74 @@
+use std::env;
+use std::fs;
+use std::path::PathBuf;
+
+fn main() {
+    // Get the workspace root (two levels up from borders-core)
+    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+    let workspace_root = manifest_dir.parent().unwrap().parent().unwrap();
+
+    // Determine if we're in production mode (CI or release profile)
+    let is_production = env::var("CI").is_ok() || env::var("PROFILE").map(|p| p == "release").unwrap_or(false);
+
+    // Read git commit from .source-commit file
+    let source_commit_path = workspace_root.join(".source-commit");
+    let git_commit = if source_commit_path.exists() {
+        match fs::read_to_string(&source_commit_path) {
+            Ok(content) => content.trim().to_string(),
+            Err(e) if is_production => {
+                panic!("Failed to read .source-commit file in production: {}", e);
+            }
+            Err(_) => "unknown".to_string(),
+        }
+    } else {
+        // Fallback to git command if file doesn't exist (local development)
+        let git_result = std::process::Command::new("git").args(["rev-parse", "HEAD"]).current_dir(workspace_root).output().ok().and_then(|output| if output.status.success() { String::from_utf8(output.stdout).ok() } else { None }).map(|s| s.trim().to_string());
+
+        match git_result {
+            Some(commit) => commit,
+            None if is_production => {
+                panic!("Failed to acquire git commit in production and .source-commit file does not exist");
+            }
+            None => "unknown".to_string(),
+        }
+    };
+
+    // Determine build time based on environment
+    let build_time = if let Ok(epoch) = env::var("SOURCE_DATE_EPOCH") {
+        // Use provided timestamp for reproducible builds
+        match epoch.parse::<i64>().ok().and_then(|ts| chrono::DateTime::from_timestamp(ts, 0)).map(|dt| dt.to_rfc3339()) {
+            Some(time) => time,
+            None if is_production => {
+                panic!("Failed to parse SOURCE_DATE_EPOCH in production: {}", epoch);
+            }
+            None => "unknown".to_string(),
+        }
+    } else if env::var("CI").is_ok() {
+        // Generate fresh timestamp in CI
+        chrono::Utc::now().to_rfc3339()
+    } else {
+        // Static value for local development
+        "dev".to_string()
+    };
+
+    // Set environment variables for compile-time access
+    println!("cargo:rustc-env=BUILD_GIT_COMMIT={}", git_commit);
+    println!("cargo:rustc-env=BUILD_TIME={}", build_time);
+
+    // Only re-run the build script when specific files change
+    println!("cargo:rerun-if-changed=build.rs");
+
+    // In CI, watch the .source-commit file if it exists
+    if source_commit_path.exists() {
+        println!("cargo:rerun-if-changed={}", source_commit_path.display());
+    }
+
+    // In local development, watch .git/HEAD to detect branch switches
+    // We intentionally don't watch the branch ref file to avoid spurious rebuilds
+    if env::var("CI").is_err() {
+        let git_head = workspace_root.join(".git").join("HEAD");
+        if git_head.exists() {
+            println!("cargo:rerun-if-changed={}", git_head.display());
+        }
+    }
+}