//! Build script for coolprop-sys.
//!
//! This compiles the CoolProp C++ library statically.
//! Supports macOS, Linux, and Windows.

use std::env;
use std::path::PathBuf;

fn coolprop_src_path() -> Option<PathBuf> {
    // Try to find CoolProp source in common locations
    let possible_paths = vec![
        // Vendor directory (recommended)
        PathBuf::from("../../vendor/coolprop")
            .canonicalize()
            .unwrap_or(PathBuf::from("../../../vendor/coolprop")),
        // External directory
        PathBuf::from("external/coolprop"),
        // System paths (Unix)
        PathBuf::from("/usr/local/src/CoolProp"),
        PathBuf::from("/opt/CoolProp"),
    ];

    possible_paths
        .into_iter()
        .find(|path| path.join("CMakeLists.txt").exists())
}

fn main() {
    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap_or_default();

    // Check if CoolProp source is available
    if let Some(coolprop_path) = coolprop_src_path() {
        println!("cargo:rerun-if-changed={}", coolprop_path.display());

        // Build CoolProp using CMake
        let dst = cmake::Config::new(&coolprop_path)
            .define("COOLPROP_SHARED_LIBRARY", "OFF")
            .define("COOLPROP_STATIC_LIBRARY", "ON")
            .define("COOLPROP_CATCH_TEST", "OFF")
            .define("COOLPROP_C_LIBRARY", "ON")
            .define("COOLPROP_MY_IFCO3_WRAPPER", "OFF")
            .build();

        println!("cargo:rustc-link-search=native={}/build", dst.display());
        println!("cargo:rustc-link-search=native={}/lib", dst.display());
        println!(
            "cargo:rustc-link-search=native={}/build",
            coolprop_path.display()
        ); // Fallback

        // Link against CoolProp statically
        println!("cargo:rustc-link-lib=static=CoolProp");

        // On macOS, force load the static library so its symbols are exported in the final cdylib
        if target_os == "macos" {
            println!(
                "cargo:rustc-link-arg=-Wl,-force_load,{}/build/libCoolProp.a",
                dst.display()
            );
        }
    } else {
        println!(
            "cargo:warning=CoolProp source not found in vendor/. \
                   For full static build, run: \
                   git clone https://github.com/CoolProp/CoolProp.git vendor/coolprop"
        );
        // Fallback for system library
        if target_os == "windows" {
            // On Windows, try to find CoolProp as a system library
            println!("cargo:rustc-link-lib=CoolProp");
        } else {
            println!("cargo:rustc-link-lib=static=CoolProp");
        }
    }

    // Link required system libraries for C++ standard library
    match target_os.as_str() {
        "macos" => {
            println!("cargo:rustc-link-lib=dylib=c++");
        }
        "linux" | "freebsd" | "openbsd" | "netbsd" => {
            println!("cargo:rustc-link-lib=dylib=stdc++");
        }
        "windows" => {
            // MSVC links the C++ runtime automatically; nothing to do.
            // For MinGW, stdc++ is needed but MinGW is less common.
        }
        _ => {
            // Best guess for unknown Unix-like targets
            println!("cargo:rustc-link-lib=dylib=stdc++");
        }
    }

    // Link libm (only on Unix; on Windows it's part of the CRT)
    if target_os != "windows" {
        println!("cargo:rustc-link-lib=dylib=m");
    }

    // Force export symbols for Python extension (macOS only)
    if target_os == "macos" {
        println!("cargo:rustc-link-arg=-Wl,-all_load");
    }
    // Linux equivalent (only for shared library builds, e.g., Python wheels)
    // Note: --whole-archive must bracket the static lib; the linker handles this
    // automatically for Rust cdylib targets, so we don't need it here.

    // Tell Cargo to rerun if build.rs changes
    println!("cargo:rerun-if-changed=build.rs");
}