use std::{env, fs, time::Instant};
use virtualmachine::Machine;
use crate::{decompiler::{operation_to_name, process}, errors::{create_error, print_error, reverse_subtype_short, reverse_type_short}, virtualmachine::VMState};

mod lexer;
mod parser;
mod enviroment;
mod compiler;
mod virtualmachine;
mod errors;
mod decompiler;

const CLIVER: [u8; 3] = [1,0,2];

#[derive(Debug, Clone)]
struct Context {
    file: String,
    raw_file: String,
    c_funcid: usize,
    known: bool
}

fn print_help() {
    println!("Usage: ASL <command> <file> [<error code>]");
    println!("Commands:");
    println!("  run       - Run an ASL/ASX file");
    println!("  compile   - Compile the ASL file to bytecode");
    println!("  traceback - Traceback an error based on an error code");
    println!("  viewx-    - View the contents of an ASX file");
}

fn main() {
    let msg = format!("Astro Lang (ASL) CLI v{}.{}.{}", CLIVER[0], CLIVER[1], CLIVER[2]);
    println!("{}", msg);
    println!("{}", "=".repeat(msg.len()));
    let args: Vec<String> = env::args().collect();
    if args.len() < 3 {
        println!("Not enough arguments provided.");
        print_help();
        return;
    }
    if args[1] == "run" {
        let file = &args[2];
        if file.ends_with(".asl") {
            let inp = fs::read_to_string(file);
            let time = Instant::now();
            match inp {
                Result::Ok(data) => {
                    let ctx = Context {
                        file: String::from(file),
                        raw_file: data.clone(),
                        c_funcid: 0,
                        known: true
                    };
                    let lexed = lexer::lex(data, &ctx);
                    let ast = parser::parse(lexed, &ctx);
                    let (compiled, contexts) = compiler::compile(ast, &ctx);
                    let ntime = time.elapsed();
                    println!("Build successful. Took: {}ms", ntime.as_millis());
                    let mut vm = Machine::new(contexts);
                    vm.load(&compiled);
                    while let VMState::Paused = vm.state {
                        vm.resume();
                    }
                    match vm.state {
                        VMState::Finished => {
                            println!("Execution finished successfully.");
                        },
                        VMState::Error(err) => {
                            print_error(&err);
                            panic!("Execution failed with an error.");
                        },
                        _ => {}
                    }
                },
                Result::Err(err) => {
                    panic!("Can't read file: {}", err);
                }
            }
        } else if file.ends_with(".asx") {
            let inp = fs::read(file);
            match inp {
                Result::Ok(data) => {
                    let decompiled = process(&data);
                    let mut contexts: Vec<Context> = Vec::new();
                    for i in 0..decompiled.func_count {
                        contexts.push(Context { file: String::from(file), raw_file: String::from("Unknown"), c_funcid: i, known: false });
                    }
                    let mut vm = Machine::new(contexts);
                    vm.load(&data);
                    while let VMState::Paused = vm.state {
                        vm.resume();
                    }
                    match vm.state {
                        VMState::Finished => {
                            println!("Execution finished successfully.");
                        },
                        VMState::Error(err) => {
                            print_error(&err);
                            panic!("Execution failed with an error.");
                        },
                        _ => {}
                    }
                },
                Result::Err(err) => {
                    panic!("Can't read file: {}", err);
                }
            }
        } else {
            println!("Unknown file type. Please use .asl or .asx files.");
        }
    } else if args[1] == "compile" {
        let file = &args[2];
        if file.ends_with(".asl") {
            let inp = fs::read_to_string(file);
            let time = Instant::now();
            match inp {
                Result::Ok(data) => {
                    let ctx = Context {
                        file: String::from(file),
                        raw_file: data.clone(),
                        c_funcid: 0,
                        known: true
                    };
                    let lexed = lexer::lex(data, &ctx);
                    let ast = parser::parse(lexed, &ctx);
                    let (compiled, _contexts) = compiler::compile(ast, &ctx);
                    match fs::write("compiled.asx", compiled) {
                        Ok(_) => {
                            let ntime = time.elapsed();
                            println!("Build successful. Took: {}ms", ntime.as_millis());
                        },
                        Err(err) => {
                            panic!("Can't write compiled file: {}", err);
                        }
                    }
                },
                Result::Err(err) => {
                    panic!("Can't read file: {}", err);
                }
            }
        } else {
            println!("Unknown file type. Please use .asl files.");
        }
    } else if args[1] == "traceback" {
        if args.len() < 4 {
            println!("Not enough arguments provided for traceback.");
            print_help();
            return;
        }
        let file = &args[2];
        if file.ends_with(".asl") {
            let inp = fs::read_to_string(file);
            let time = Instant::now();
            match inp {
                Result::Ok(data) => {
                    let ctx = Context {
                        file: String::from(file),
                        raw_file: data.clone(),
                        c_funcid: 0,
                        known: true
                    };
                    let lexed = lexer::lex(data, &ctx);
                    let ast = parser::parse(lexed, &ctx);
                    let (compiled, contexts) = compiler::compile(ast, &ctx);
                    let ntime = time.elapsed();
                    println!("Build successful. Took: {}ms", ntime.as_millis());
                    let decompiled = process(&compiled);
                    let errcode_data: Vec<&str> = args[3].split(":").collect();
                    if decompiled.func_count <= errcode_data[2].parse().unwrap() {
                        println!("Error code {} is invalid for this file.", args[3]);
                        return;
                    }
                    let func_ctx = contexts[errcode_data[2].parse::<usize>().unwrap()].clone();
                    let error = create_error("", errcode_data[3].parse().unwrap(), reverse_type_short(errcode_data[0].to_string()), reverse_subtype_short(errcode_data[1].to_string()), &func_ctx);
                    print_error(&error);
                    return;
                },
                Result::Err(err) => {
                    panic!("Can't read file: {}", err);
                }
            }
        } else {
            println!("Unknown file type. Please use .asl files.");
        }
    } else if args[1] == "viewx" {
        let file = &args[2];
        if file.ends_with(".asx") {
            let inp = fs::read(file);
            match inp {
                Result::Ok(data) => {
                    let decompiled = process(&data);
                    println!("ASX Verion: {}", decompiled.version);
                    println!("Function Count: {}", decompiled.func_count);
                    for i in 0..decompiled.func_count {
                        println!("Function {}:", i);
                        let func = &decompiled.functions[i];
                        println!("  Variables:");
                        for var in &func.variables {
                            println!("    {}: {} ({}:{})", var.id, var.name, var.start, var.end);
                        }
                        println!("  Strings:");
                        for (id, string) in &func.strings {
                            println!("    {}: {}", id, string);
                        }
                        println!("  Functions:");
                        for (id, pos) in &func.functions {
                            println!("    {}: {}", id, pos);
                        }
                        println!("  Try/Catch: {}", func.try_catch);
                        println!("  Body:");
                        //Print these under each other like when you tabulate
                        let mut longest_cols: Vec<usize> = vec![0, 0, 0, 0];
                        for op in &func.body {
                            longest_cols[0] = longest_cols[0].max(operation_to_name(op.opcode).len());
                            longest_cols[1] = longest_cols[1].max(op.arg1.to_string().len());
                            longest_cols[2] = longest_cols[2].max(op.arg2.to_string().len());
                            longest_cols[3] = longest_cols[3].max(op.arg3.to_string().len());
                        }
                        let mut longest = 0;
                        for op in &func.body {
                            let op_name = operation_to_name(op.opcode);
                            let str = format!("    {}{} {}{} {}{} {}{} at {}", 
                                " ".repeat(longest_cols[0] - op_name.len()),
                                op_name, 
                                " ".repeat(longest_cols[1] - op.arg1.to_string().len()), 
                                op.arg1, 
                                " ".repeat(longest_cols[2] - op.arg2.to_string().len()), 
                                op.arg2, 
                                " ".repeat(longest_cols[3] - op.arg3.to_string().len()),
                                op.arg3,
                                op.pos);
                            longest = longest.max(str.len()+4);
                            println!("{}", str);
                        }
                        println!("{}", "=".repeat(longest));
                    }
                },
                Result::Err(err) => {
                    panic!("Can't read file: {}", err);
                }
            }
        } else {
            println!("Unknown file type. Please use .asx files.");
        }
    } else {
        println!("Invalid command.");
        print_help();
    }
}