// Copyright 2021-2024 Vector 35 Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::{
    binaryview,
    rc,
    string::{BnStrCompatible, IntoJson},
};

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

#[cfg(not(target_os = "windows"))]
fn binja_path() -> PathBuf {
    use std::ffi::{CStr, OsStr};
    use std::mem;
    use std::os::raw;
    use std::os::unix::ffi::OsStrExt;

    #[repr(C)]
    struct DlInfo {
        dli_fname: *const raw::c_char,
        dli_fbase: *mut raw::c_void,
        dli_sname: *const raw::c_char,
        dli_saddr: *mut raw::c_void,
    }

    if let Ok(p) = env::var("BINJA_DIR") {
        return PathBuf::from(p);
    }

    extern "C" {
        fn dladdr(addr: *mut raw::c_void, info: *mut DlInfo) -> raw::c_int;
    }

    unsafe {
        let mut info: DlInfo = mem::zeroed();

        if dladdr(BNSetBundledPluginDirectory as *mut _, &mut info) == 0 {
            panic!("Failed to find libbinaryninjacore path!");
        }

        if info.dli_fname.is_null() {
            panic!("Failed to find libbinaryninjacore path!");
        }

        let path = CStr::from_ptr(info.dli_fname);
        let path = OsStr::from_bytes(path.to_bytes());
        let mut path = PathBuf::from(path);
        while path.is_symlink() {
            path = path
                .read_link()
                .expect("Failed to find libbinaryninjacore path!");
        }

        path.pop();
        path
    }
}

#[cfg(target_os = "windows")]
fn binja_path() -> PathBuf {
    PathBuf::from(env::var("PROGRAMFILES").unwrap()).join("Vector35\\BinaryNinja\\")
}

use binaryninjacore_sys::{BNInitPlugins, BNInitRepoPlugins, BNSetBundledPluginDirectory};

/// Loads plugins, core architecture, platform, etc.
///
/// ⚠️ Important! Must be called at the beginning of scripts.  Plugins do not need to call this. ⚠️
///
/// You can instead call this through [`Session`] or [`script_helper`]
pub fn init() {
    unsafe {
        let path = binja_path().join("plugins").into_os_string();
        let path = path.into_string().unwrap();

        BNSetBundledPluginDirectory(path.as_str().into_bytes_with_nul().as_ptr() as *mut _);
        BNInitPlugins(true);
        BNInitRepoPlugins();
    }
}

/// Unloads plugins, stops all worker threads, and closes open logs
///
/// ⚠️ Important! Must be called at the end of scripts. ⚠️
pub fn shutdown() {
    unsafe { binaryninjacore_sys::BNShutdown() };
}

pub fn is_shutdown_requested() -> bool {
    unsafe { binaryninjacore_sys::BNIsShutdownRequested() }
}

/// Prelued-postlued helper function (calls [`init`] and [`shutdown`] for you)
/// ```no_run
/// # use binaryninja::binaryview::BinaryViewExt;
/// binaryninja::headless::script_helper(|| {
///     let cat = binaryninja::load("/bin/cat").expect("Couldn't open `/bin/cat`");
///     for function in cat.functions().iter() {
///         println!("  `{}`", function.symbol().full_name());
///     }
/// });
/// ```
pub fn script_helper(func: fn()) {
    init();
    func();
    shutdown();
}

/// Wrapper for [`init`] and [`shutdown`]. Instantiating this at the top of your script will initialize everything correctly and then clean itself up at exit as well.
pub struct Session {}

impl Session {
    pub fn new() -> Self {
        init();
        Self {}
    }

    /// ```no_run
    /// let headless_session = binaryninja::headless::Session::new();
    ///
    /// let bv = headless_session.load("/bin/cat").expect("Couldn't open `/bin/cat`");
    /// ```
    pub fn load(&self, filename: &str) -> Option<rc::Ref<binaryview::BinaryView>> {
        crate::load(filename)
    }

    /// ```no_run
    /// use binaryninja::{metadata::Metadata, rc::Ref};
    /// use std::collections::HashMap;
    ///
    /// let settings: Ref<Metadata> = HashMap::from([
    ///     ("analysis.linearSweep.autorun", false.into()),
    /// ]).into();
    /// let headless_session = binaryninja::headless::Session::new();
    ///
    /// let bv = headless_session.load_with_options("/bin/cat", true, Some(settings))
    ///     .expect("Couldn't open `/bin/cat`");
    /// ```
    pub fn load_with_options<O: IntoJson>(
        &self,
        filename: &str,
        update_analysis_and_wait: bool,
        options: Option<O>,
    ) -> Option<rc::Ref<binaryview::BinaryView>> {
        crate::load_with_options(filename, update_analysis_and_wait, options)
    }
}

impl Default for Session {
    fn default() -> Self {
        Self::new()
    }
}

impl Drop for Session {
    fn drop(&mut self) {
        shutdown()
    }
}