use std::collections::BTreeSet;
use std::fs;
use std::path::{Path, PathBuf};

const ALLOWED_DEPENDENCIES: [&str; 8] = [
    "libremetaverse",
    "libremetaverse-types",
    "reqwest",
    "serde",
    "serde_json",
    "sha2",
    "tokio",
    "url",
];

#[test]
fn package_has_only_reviewed_rust_dependencies_and_no_build_script() {
    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    assert!(
        !root.join("build.rs").exists(),
        "agent must not have a build script"
    );
    let manifest = fs::read_to_string(root.join("Cargo.toml")).expect("read package manifest");
    let dependency_section = manifest
        .split("[dependencies]")
        .nth(1)
        .expect("dependency section")
        .split("\n[")
        .next()
        .expect("end of dependency section");
    let observed = dependency_section
        .lines()
        .filter_map(|line| line.split_once('=').map(|(name, _)| name.trim()))
        .filter(|name| !name.is_empty())
        .collect::<BTreeSet<_>>();
    assert_eq!(
        observed,
        ALLOWED_DEPENDENCIES.into_iter().collect(),
        "every direct dependency needs explicit policy review"
    );
}

#[test]
fn runtime_source_has_no_subprocess_or_native_abi_escape_hatch() {
    let source = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("src");
    let mut files = Vec::with_capacity(8);
    collect_rust_files(&source, &mut files);
    assert!(
        files.len() <= 12,
        "source-file count needs a reviewed bound update"
    );
    for path in files {
        let text = fs::read_to_string(&path).expect("read runtime source");
        for forbidden in [
            "std::process::Command",
            "tokio::process",
            "Command::new(",
            "extern \"C\"",
            "#[link(",
            "unsafe fn ",
            "unsafe impl ",
        ] {
            assert!(
                !text.contains(forbidden),
                "{} contains forbidden runtime boundary {forbidden:?}",
                path.display()
            );
        }
        assert!(
            !text.lines().any(|line| {
                let line = line.trim_start();
                line.starts_with("unsafe {") || line.contains("= unsafe {")
            }),
            "{} contains an unsafe block",
            path.display()
        );
    }
}

#[test]
fn world_backend_requires_the_opaque_policy_authorization() {
    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    let backend = fs::read_to_string(root.join("src/backend.rs")).expect("backend source");
    assert!(backend.contains("action: AuthorizedAction"));
    assert!(!backend.contains("call: ProposedToolCall"));
    assert!(!backend.contains("decision: PolicyDecision"));
}

#[test]
fn live_session_adapter_reuses_only_the_native_network_manager_lifecycle() {
    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    let backend = fs::read_to_string(root.join("src/backend.rs")).expect("backend source");
    for required in [
        ".native_default_login_params(",
        ".native_login(",
        ".native_subscribe_disconnected(",
        ".native_subscribe_event_queue_running(",
        ".native_logout_async(",
    ] {
        assert!(
            backend.contains(required),
            "missing native lifecycle {required}"
        );
    }
    assert!(!backend.contains("reqwest"));
}

fn collect_rust_files(directory: &Path, output: &mut Vec<PathBuf>) {
    for entry in fs::read_dir(directory).expect("read source directory") {
        let path = entry.expect("source entry").path();
        if path.is_dir() {
            collect_rust_files(&path, output);
        } else if path.extension().is_some_and(|extension| extension == "rs") {
            output.push(path);
        }
    }
}