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

fn main() {
    maybe_override_tauri_config_for_tests();
    setup_tdlib();
    tauri_build::build();
}

fn maybe_override_tauri_config_for_tests() {
    let profile = env::var("PROFILE").unwrap_or_default();
    let skip_resources = env::var("TAURI_SKIP_RESOURCES").is_ok() || profile == "test";
    if !skip_resources {
        return;
    }

    let manifest_dir =
        PathBuf::from(env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR not set"));
    let config_path = manifest_dir.join("tauri.conf.json");
    let Ok(raw) = std::fs::read_to_string(&config_path) else {
        println!("cargo:warning=Failed to read tauri.conf.json; keeping default config");
        return;
    };

    let mut value: serde_json::Value = match serde_json::from_str(&raw) {
        Ok(value) => value,
        Err(err) => {
            println!("cargo:warning=Failed to parse tauri.conf.json: {err}");
            return;
        }
    };

    if let Some(bundle) = value.get_mut("bundle").and_then(|b| b.as_object_mut()) {
        bundle.insert("resources".to_string(), serde_json::Value::Array(Vec::new()));
    }

    let out_dir = env::var("OUT_DIR").unwrap_or_else(|_| ".".into());
    let override_path = PathBuf::from(out_dir).join("tauri.conf.test.json");
    if std::fs::write(&override_path, serde_json::to_string_pretty(&value).unwrap_or(raw)).is_ok()
    {
        env::set_var("TAURI_CONFIG", &override_path);
        println!(
            "cargo:warning=TAURI resources disabled for test build (using {})",
            override_path.display()
        );
    }
}

#[cfg(not(any(target_os = "android", target_os = "ios")))]
fn setup_tdlib() {
    // local-tdlib: use LOCAL_TDLIB_PATH or auto-detect tdlib-cache/
    if std::env::var("LOCAL_TDLIB_PATH").is_err() {
        let manifest_dir =
            PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR"));
        let arch = std::env::var("CARGO_CFG_TARGET_ARCH").unwrap_or_else(|_| "aarch64".into());
        let arch_name = if arch == "aarch64" { "aarch64" } else { "x86_64" };
        let os = std::env::var("CARGO_CFG_TARGET_OS").unwrap_or_else(|_| "macos".into());
        let os_arch = if os == "macos" || os == "darwin" {
            format!("macos-{arch_name}")
        } else if os == "linux" {
            format!("linux-{arch_name}")
        } else if os == "windows" {
            format!("windows-{arch_name}")
        } else {
            arch_name.to_string()
        };
        let default = manifest_dir.join("tdlib-cache").join(&os_arch);
        if default.join("lib").exists() {
            std::env::set_var("LOCAL_TDLIB_PATH", &default);
        } else {
            panic!(
                "LOCAL_TDLIB_PATH not set and tdlib-cache not found at {}.\n\
                 Run: cd src-tauri && ./scripts/download-tdlib.sh\n\
                 Then retry the build.",
                default.display()
            );
        }
    }
    tdlib_rs::build::build(None);

    // On macOS, replace the bundled dylib with our source-built version
    // that targets macOS 10.15 (the prebuilt one targets macOS 14.0)
    #[cfg(target_os = "macos")]
    copy_local_tdlib_for_bundle();
}

#[cfg(any(target_os = "android", target_os = "ios"))]
fn setup_tdlib() {
    // No TDLib on mobile
}

/// On macOS, copy the source-built TDLib dylib (with 10.15 deployment target)
/// to libraries/ for Tauri bundler. Lookup order:
///   1. tdlib-prebuilt/macos-<arch>/  (committed to git, no build needed)
///   2. tdlib-local/lib/              (local build via build-tdlib-from-source.sh)
///   3. download-tdlib output         (fallback, targets macOS 14.0+)
#[cfg(target_os = "macos")]
fn copy_local_tdlib_for_bundle() {
    use std::path::PathBuf;

    let manifest_dir =
        PathBuf::from(env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR not set"));
    let libraries_dir = manifest_dir.join("libraries");

    // Use CARGO_CFG_TARGET_ARCH to handle cross-compilation (e.g. arm64 host → x86_64 target)
    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap_or_else(|_| "aarch64".into());
    let arch_name = match target_arch.as_str() {
        "aarch64" => "arm64",
        other => other,
    };

    let tdlib_version = "1.8.29";
    let dylib_name = format!("libtdjson.{tdlib_version}.dylib");

    // 1. Check tdlib-prebuilt/ (committed to git)
    let prebuilt = manifest_dir
        .join("tdlib-prebuilt")
        .join(format!("macos-{arch_name}"))
        .join(&dylib_name);

    // 2. Check tdlib-local/<arch>/ (local source build)
    let local = manifest_dir
        .join("tdlib-local")
        .join(arch_name)
        .join("lib")
        .join(&dylib_name);

    let src_dylib = if prebuilt.exists() {
        println!("cargo:warning=Using prebuilt TDLib from {}", prebuilt.display());
        prebuilt
    } else if local.exists() {
        println!("cargo:warning=Using locally-built TDLib from {}", local.display());
        local
    } else {
        // 3. Fall back to tdlib-cache (from download-tdlib.sh) or LOCAL_TDLIB_PATH
        let local_tdlib = env::var("LOCAL_TDLIB_PATH")
            .map(PathBuf::from)
            .unwrap_or_else(|_| {
                manifest_dir
                    .join("tdlib-cache")
                    .join(format!("macos-{arch_name}"))
            });
        println!("cargo:warning=Using TDLib from {}", local_tdlib.display());
        local_tdlib.join("lib").join(&dylib_name)
    };

    if !src_dylib.exists() {
        println!("cargo:warning=TDLib dylib not found at {}", src_dylib.display());
        return;
    }

    let dst_dylib = libraries_dir.join(&dylib_name);
    std::fs::create_dir_all(&libraries_dir).expect("Failed to create libraries/");
    std::fs::copy(&src_dylib, &dst_dylib).expect("Failed to copy TDLib dylib to libraries/");
    set_permissions_rw(&dst_dylib);
    fix_install_name(&dst_dylib, &dylib_name);

    // Add rpath so the binary finds the dylib in Contents/Frameworks/
    println!("cargo:rustc-link-arg=-Wl,-rpath,@executable_path/../Frameworks");
}

#[cfg(target_os = "macos")]
fn fix_install_name(dylib_path: &std::path::Path, dylib_name: &str) {
    run_cmd(
        "install_name_tool",
        &[
            "-id",
            &format!("@rpath/{dylib_name}"),
            dylib_path.to_str().unwrap(),
        ],
    );
}

#[cfg(target_os = "macos")]
fn set_permissions_rw(path: &std::path::Path) {
    use std::os::unix::fs::PermissionsExt;
    let mut perms = std::fs::metadata(path)
        .expect("Failed to read metadata")
        .permissions();
    perms.set_mode(0o755);
    std::fs::set_permissions(path, perms).expect("Failed to set permissions");
}

#[cfg(target_os = "macos")]
fn run_cmd(cmd: &str, args: &[&str]) {
    let status = std::process::Command::new(cmd)
        .args(args)
        .status()
        .unwrap_or_else(|e| panic!("Failed to run {cmd}: {e}"));
    if !status.success() {
        panic!("{cmd} failed with exit code {:?}", status.code());
    }
}