#![cfg(feature = "nix-util-c")]
#![cfg(test)]

use core::ffi::{CStr, c_char, c_uint, c_void};
use std::ffi::CString;
use std::{slice, str};

use serial_test::serial;

use nixide_sys::*;

#[test]
#[serial]
fn context_create_and_free() {
    unsafe {
        let ctx = nix_c_context_create();
        assert!(!ctx.is_null());
        nix_c_context_free(ctx);
    }
}

#[test]
#[serial]
fn libutil_init() {
    unsafe {
        let ctx = nix_c_context_create();
        assert!(!ctx.is_null());
        let err = nix_libutil_init(ctx);
        assert_eq!(err, NixErr::Ok);
        nix_c_context_free(ctx);
    }
}

#[test]
#[serial]
fn version_get() {
    unsafe {
        let version_ptr = nix_version_get();
        assert!(!version_ptr.is_null());
        let version = CStr::from_ptr(version_ptr).to_string_lossy();
        assert!(!version.is_empty(), "Version string should not be empty");
        assert!(
            version.chars().next().unwrap().is_ascii_digit(),
            "Version string should start with a digit: {version}"
        );
    }
}

#[test]
#[serial]
fn setting_set_and_get() {
    unsafe extern "C" fn string_callback(start: *const c_char, n: c_uint, user_data: *mut c_void) {
        let s = unsafe { slice::from_raw_parts(start.cast::<u8>(), n as usize) };
        let s = str::from_utf8(s).unwrap();
        let out = user_data.cast::<Option<String>>();
        *unsafe { &mut *out } = Some(s.to_string());
    }

    unsafe {
        let ctx = nix_c_context_create();
        assert!(!ctx.is_null());
        let err = nix_libutil_init(ctx);
        assert_eq!(err, NixErr::Ok);

        // Set a setting (use a dummy/extra setting to avoid breaking global config)
        let key = CString::new("extra-test-setting").unwrap();
        let value = CString::new("test-value").unwrap();
        let set_err = nix_setting_set(ctx, key.as_ptr(), value.as_ptr());
        // Setting may not exist, but should not crash
        assert!(
            set_err == NixErr::Ok || set_err == NixErr::Key,
            "Unexpected error code: {set_err}"
        );

        // Try to get the setting (may not exist, but should not crash)
        let mut got: Option<String> = None;
        let get_err = nix_setting_get(
            ctx,
            key.as_ptr(),
            Some(string_callback),
            (&raw mut got).cast(),
        );
        assert!(
            get_err == NixErr::Ok || get_err == NixErr::Key,
            "Unexpected error code: {get_err}"
        );
        // If OK, we should have gotten a value
        if get_err == NixErr::Ok {
            assert_eq!(got.as_deref(), Some("test-value"));
        }

        nix_c_context_free(ctx);
    }
}

#[test]
#[serial]
fn error_handling_apis() {
    unsafe extern "C" fn string_callback(start: *const c_char, n: c_uint, user_data: *mut c_void) {
        let s = unsafe { slice::from_raw_parts(start.cast::<u8>(), n as usize) };
        let s = str::from_utf8(s).unwrap();
        let out = user_data.cast::<Option<String>>();
        *unsafe { &mut *out } = Some(s.to_string());
    }

    unsafe {
        let ctx = nix_c_context_create();
        assert!(!ctx.is_null());
        let err = nix_libutil_init(ctx);
        assert_eq!(err, NixErr::Ok);

        // Set an error message
        let msg = CString::new("custom error message").unwrap();
        let set_err = nix_set_err_msg(ctx, NixErr::Unknown, msg.as_ptr());
        assert_eq!(set_err, NixErr::Unknown);

        // Get error code
        let code = nix_err_code(ctx);
        assert_eq!(code, NixErr::Unknown);

        // Get error message
        let mut len: c_uint = 0;
        let err_msg_ptr = nix_err_msg(ctx, ctx, &mut len as *mut _);
        if !err_msg_ptr.is_null() && len > 0 {
            let err_msg = str::from_utf8(slice::from_raw_parts(
                err_msg_ptr as *const u8,
                len as usize,
            ))
            .unwrap();
            assert!(err_msg.contains("custom error message"));
        }

        // Get error info message (should work, but may be empty)
        let mut info: Option<String> = None;
        let _ = nix_err_info_msg(ctx, ctx, Some(string_callback), (&raw mut info).cast());

        // Get error name (should work, but may be empty)
        let mut name: Option<String> = None;
        let _ = nix_err_name(ctx, ctx, Some(string_callback), (&raw mut name).cast());

        // Clear error
        nix_clear_err(ctx);
        let code_after_clear = nix_err_code(ctx);
        assert_eq!(code_after_clear, NixErr::Ok);

        nix_c_context_free(ctx);
    }
}