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#![warn(missing_docs)]

//! A library to handle Quake 3 virtual machines.

// Both `nom` and `error_chain` can recurse deeply
#![recursion_limit="1024"]

#[macro_use]
extern crate error_chain;
#[macro_use]
extern crate nom;

pub mod errors;
pub mod bytecode;
pub mod opcodes;
pub mod parser;

pub use bytecode::Instruction;

use errors::*;

const VM_MAGIC: [u8; 4] = [0x44, 0x14, 0x72, 0x12];

/// A Quake 3 virtual machine image.
///
/// A VM consists of instructions and data, where data is separated into
///
/// * word-sized data
/// * byte-sized data (LIT)
/// * uninitialized data (BSS)
#[derive(Debug,PartialEq)]
pub struct QVM {
    code: Vec<Instruction>,
    data: Vec<u32>,
    lit: Vec<u8>,
    bss_length: u32,
}

impl QVM {
    // TODO: Validate instructions; addresses might be out of bounds etc.
    /// Creates a new VM instance.
    ///
    /// # Errors
    /// lorem ipsum
    pub fn new(code: Vec<Instruction>,
               data: Vec<u32>,
               lit: Vec<u8>,
               bss_length: u32)
               -> Result<QVM> {
        Ok(QVM {
               code: code,
               data: data,
               lit: lit,
               bss_length: bss_length,
           })
    }

    /// Returns the instructions of the code segment.
    pub fn instructions(&self) -> &Vec<Instruction> {
        &self.code
    }

    /// Returns the word-sized data of the data segment.
    pub fn data(&self) -> &Vec<u32> {
        &self.data
    }

    /// Returns the byte-sized data of the LIT segment.
    pub fn lit(&self) -> &Vec<u8> {
        &self.lit
    }

    /// Returns the length of the uninitialized BSS segment.
    pub fn bss_length(&self) -> u32 {
        self.bss_length
    }
}

/// The different segments/sections in a QVM file.
///
/// See ioquake3's `segmentName_t` in `tools/asm/q3asm.c`
// These should match the names in ioquake3
#[allow(non_camel_case_types)]
#[derive(Debug, Clone, Copy)]
pub enum Segment {
    /// The code segment, consisting of instructions.
    CODE,
    /// The data segment, consisting of word-sized data.
    DATA,
    /// The LIT segment, consisting of byte-sized data.
    LIT,
    /// The BSS pseudo-segment, consisting of uninitialized data.
    BSS,
    /// The jump table targets pseudo-segment, consisting of jump label addresses.
    JTRG,
}