/*
* Copyright (C) 2023  The Trinitrix Project <soispha@vhack.eu, antifallobst@systemausfall.org>
*
* This file is part of the Trixy crate for Trinitrix.
*
* Trixy is free software: you can redistribute it and/or modify
* it under the terms of the Lesser GNU General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* and the Lesser GNU General Public License along with this program.
* If not, see <https://www.gnu.org/licenses/>.
*/




use std::{env, fs, io::Write, path::PathBuf, process::Command};

use trixy_lang_parser::parse_trixy_lang;

use crate::config::TrixyConfig;

pub mod config;
mod generate;

const VIM_LINE_RUST: &'static str = "// vim: filetype=rust\n";
const VIM_LINE_C: &'static str = "// vim: filetype=c\n";

impl TrixyConfig {
    /// This is the heart of Trixy
    /// It mainly does one thing:
    ///     - Generate a tree of modules from the input trixy file
    ///
    pub fn generate(&self) {
        let source_code = fs::read_to_string(&self.trixy_path).unwrap_or_else(|err| {
            panic! {"Can't read file at path: '{}'. The Error is: '{}'",
            self.trixy_path.display(), err};
        });

        let trixy_code = parse_trixy_lang(&source_code).unwrap_or_else(|err| {
            panic! {"Parsing of the trixy file failed: \n{}", err}
        });

        // host code
        let host_code = prettyplease::unparse(
            &syn::parse2(generate::generate(&trixy_code, &self))
                .expect("This code was generated, it should also be parsable"),
        );
        let mut host_code_out = fs::File::create(PathBuf::from(format!(
            "{}/{}",
            env::var("OUT_DIR").expect("The build script should have this define"),
            &self.host_code_name.display()
        )))
        .expect("This file should always be free to use");
        write!(host_code_out, "{}\n{}", host_code, VIM_LINE_RUST).expect("Write should work");

        // c header
        let c_header = generate::c_api::header::generate(&trixy_code, &self);
        let c_header_path = PathBuf::from(format!(
            "{}/{}",
            env::var("OUT_DIR").expect("The build script should have this define"),
            &self.c_header_name.display()
        ));
        let mut c_header_out =
            fs::File::create(&c_header_path).expect("This file should always be free to use");
        write!(c_header_out, "{}\n{}", c_header, VIM_LINE_C).expect("Write should work");

        Command::new("clang-format")
            .args(["-i", &c_header_path.to_str().unwrap()])
            .status()
            .unwrap_or_else(|err| {
                panic!(
                    "Failed to format the c header file with `clang-format`; Error: `{}`",
                    err
                )
            });

        if let Some(dist_dir) = &self.dist_dir_path {
            if !dist_dir.is_dir() {
                fs::create_dir(dist_dir).unwrap_or_else(|err| {
                    panic! {
                    "Failed to create the dist directory ('{}') because of: `{}`",
                    dist_dir.display(), err}
                });
            }
            if self.check_dist_dir {
                if dist_dir.read_dir().iter().count() != 1 {
                    panic!("Your specified dist dir already has something in it! Set `check_dist_dir` to `false` to override this check");
                }
            }
            let c_header_dist = PathBuf::from(format!(
                "{}/{}",
                dist_dir.display(),
                self.c_header_name.display()
            ));
            fs::copy(c_header_path, c_header_dist).unwrap_or_else(
                |err| panic! {"Failed to copy the c header to the dist dir because of: `{}`", err},
            );
        }
    }
}