#![forbid(unsafe_code)]
#![warn(clippy::all)]

mod args;
#[cfg(feature = "compiler")]
mod compiler;
mod errors;
mod file_io;
#[cfg(feature = "compiler")]
mod parser;
mod vm;

use file_io::open_bytecode;
#[cfg(feature = "compiler")]
use file_io::{into_bytecode, open_source, write_bytecode};
#[cfg(feature = "compiler")]
use std::env;
use std::path::Path;
#[cfg(feature = "compiler")]
use std::path::PathBuf;

use args::*;
#[cfg(feature = "compiler")]
use compiler::Compiler;
#[cfg(feature = "compiler")]
use errors::GenericError;
#[cfg(feature = "compiler")]
use parser::Parser;
#[cfg(feature = "compiler")]
use vm::FunctionSignature;
use vm::{BuiltinFunctionDef, BuiltinFunctions, CompiledReid, Value, VariableType, VirtualMachine};

fn main() {
    let print = BuiltinFunctionDef::new(
        "print",
        vec![VariableType::TypeString],
        Box::new(move |args| {
            if let Value::StringVal(string) = &args[0] {
                println!("{}", string);
            }
        }),
    );
    let builtin_functions = BuiltinFunctions(vec![print]);

    let opt: MainOpt = argh::from_env();

    #[cfg(feature = "compiler")]
    if let Some(run_path) = opt.run_path {
        run_bytecode(&run_path, builtin_functions);
    } else if let Some(subcommand) = opt.subcommand {
        match subcommand {
            Subcommand::Compile(opt) => {
                let source = Path::new(&opt.source);
                let output = if let Some(output) = opt.output {
                    PathBuf::from(output)
                } else {
                    source.with_extension("reidc")
                };
                let compiled = compile(source, builtin_functions.signatures());
                match compiled {
                    Ok(compiled) => {
                        let bytecode = into_bytecode(&compiled);
                        if let Err(err) = write_bytecode(bytecode, &output) {
                            eprintln!("{}", err);
                            std::process::exit(1);
                        }
                    }
                    Err(error) => {
                        eprintln!("{}", error);
                        std::process::exit(1);
                    }
                }
            }
            Subcommand::Run(opt) => {
                let path = Path::new(&opt.source);
                let compiled = compile(path, builtin_functions.signatures());
                match compiled {
                    Ok(compiled) => run(compiled, builtin_functions),
                    Err(error) => {
                        eprintln!("{}", error);
                        std::process::exit(1);
                    }
                }
            }
        }
    } else {
        let command = env::args().collect::<Vec<String>>().join(" ");
        eprintln!("Please try running instead:");
        eprintln!("  {} <path>", command);
        eprintln!("  {} help", command);
    }

    #[cfg(not(feature = "compiler"))]
    run_bytecode(&opt.run_path, builtin_functions);
}

fn run_bytecode(run_path: &Path, builtin_functions: BuiltinFunctions) {
    let compiled = open_bytecode(run_path);
    dbg!(&compiled);
    match compiled {
        Ok(compiled) => run(compiled, builtin_functions),
        Err(error) => {
            eprintln!("{}", error);
            std::process::exit(1);
        }
    }
}

#[cfg(feature = "compiler")]
fn compile(path: &Path, builtin: Vec<FunctionSignature>) -> Result<CompiledReid, GenericError> {
    let parsed = Parser::from(open_source(&path)?).parse()?;
    //dbg!(&parsed);

    let compiled = Compiler::from(parsed)
        .with_builtin_functions(builtin)
        .compile()?;
    //dbg!(&compiled);

    Ok(compiled)
}

fn run(reid: CompiledReid, builtin: BuiltinFunctions) {
    let mut vm = VirtualMachine::from(reid);
    vm.add_builtin_functions(builtin);
    if let Err(error) = vm.run() {
        eprintln!("Runtime panic: {:#?}", error);
        std::process::exit(1);
    }
}