use crate::durandal::{bin::*, chunk::*, err::*, fx32::*, text::mac_roman_conv};
use bitflags::bitflags;
use std::fmt;

impl Chunked<Point> for Point
{
   const SIZE_CHUNK: usize = 4;

   fn read(b: &[u8]) -> ResultS<Point>
   {
      let x = b.c_i16b(0)?;
      let y = b.c_i16b(2)?;
      Ok(Point{x, y})
   }
}

impl Chunked<Endpoint> for Endpoint
{
   const SIZE_CHUNK: usize = 16;

   fn read(b: &[u8]) -> ResultS<Endpoint>
   {
      let flags   = b.c_u16b(0)?;
      let adj_hi  = b.c_i16b(2)?;
      let adj_lo  = b.c_i16b(4)?;
      let pos     = Point::read(&b[6..10])?;
      let support = b.c_u16b(14)?;
      let flags   = EndpointFlags::from_bits_truncate(flags);
      Ok(Endpoint{flags, adj_hi, adj_lo, pos, support})
   }
}

impl Chunked<Line> for Line
{
   const SIZE_CHUNK: usize = 32;

   fn read(b: &[u8]) -> ResultS<Line>
   {
      let epnt_f = b.c_u16b(0)?;
      let epnt_b = b.c_u16b(2)?;
      let flags  = b.c_u16b(4)?;
      let length = b.c_i16b(6)?;
      let adj_hi = b.c_i16b(8)?;
      let adj_lo = b.c_i16b(10)?;
      let side_f = b.c_u16b(12)?;
      let side_b = b.c_u16b(14)?;
      let poly_f = b.c_u16b(16)?;
      let poly_b = b.c_u16b(18)?;
      let flags  = LineFlags::from_bits_truncate(flags);
      Ok(Line{flags, length, adj_hi, adj_lo, epnt_f, epnt_b, side_f, side_b,
              poly_f, poly_b})
   }
}

fn read_side_tex(b: &[u8]) -> ResultS<SideTex>
{
   let offs   = Point::read(&b[0..4])?;
   let tex_id = b.c_u16b(4)?;
   let tex_id = if tex_id == 65535 {None} else {Some(tex_id)};
   Ok(SideTex{offs, tex_id})
}

impl Chunked<Side> for Side
{
   const SIZE_CHUNK: usize = 64;

   fn read(b: &[u8]) -> ResultS<Side>
   {
      let stype    = b.c_u16b(0)?;
      let flags    = b.c_u16b(2)?;
      let tex_pri  = read_side_tex(&b[4..10])?;
      let tex_sec  = read_side_tex(&b[10..16])?;
      let tex_tra  = read_side_tex(&b[16..22])?;
      let ex_tleft = Point::read(&b[22..26])?;
      let ex_trigh = Point::read(&b[26..30])?;
      let ex_bleft = Point::read(&b[30..34])?;
      let ex_brigh = Point::read(&b[34..38])?;
      let paneltyp = b.c_u16b(38)?;
      let paneldat = b.c_i16b(40)?;
      let xfer_pri = b.c_u16b(42)?;
      let xfer_sec = b.c_u16b(44)?;
      let xfer_tra = b.c_u16b(46)?;
      let shade    = b.c_u32b(48)?;
      let flags    = SideFlags::from_bits_truncate(flags);
      let shade    = Fx32::from_bits(shade);
      Ok(Side{stype, flags, tex_pri, tex_sec, tex_tra, ex_tleft, ex_trigh,
              ex_bleft, ex_brigh, paneltyp, paneldat, xfer_pri, xfer_sec,
              xfer_tra, shade})
   }
}

impl Chunker<Minf> for Minf
{
   fn chunk(b: &[u8]) -> ResultS<Minf>
   {
      let env_code = b.c_u16b(0)?;
      let physi_id = b.c_u16b(2)?;
      let music_id = b.c_u16b(4)?;
      let msn_flag = b.c_u16b(6)?;
      let env_flag = b.c_u16b(8)?;
      let levelnam = mac_roman_conv(&b[18..84]);
      let ent_flag = b.c_u32b(84)?;
      let msn_flag = MsnFlags::from_bits_truncate(msn_flag);
      let env_flag = EnvFlags::from_bits_truncate(env_flag);
      let ent_flag = EntFlags::from_bits_truncate(ent_flag);
      Ok(Minf{env_code, physi_id, music_id, msn_flag, env_flag, ent_flag,
              levelnam})
   }
}

type Unit = i16;

pub struct Point
{
   x: Unit,
   y: Unit,
}

#[derive(Debug)]
pub struct Endpoint
{
   flags:   EndpointFlags,
   adj_hi:  Unit,
   adj_lo:  Unit,
   pos:     Point,
   support: u16,
}

#[derive(Debug)]
pub struct Line
{
   flags:  LineFlags,
   length: Unit,
   adj_hi: Unit,
   adj_lo: Unit,
   epnt_f: u16,
   epnt_b: u16,
   side_f: u16,
   side_b: u16,
   poly_f: u16,
   poly_b: u16,
}

#[derive(Debug)]
pub struct SideTex
{
   offs:   Point,
   tex_id: Option<u16>,
}

#[derive(Debug)]
pub struct Side
{
   stype:    u16,
   flags:    SideFlags,
   tex_pri:  SideTex,
   tex_sec:  SideTex,
   tex_tra:  SideTex,
   ex_tleft: Point,
   ex_trigh: Point,
   ex_bleft: Point,
   ex_brigh: Point,
   paneltyp: u16,
   paneldat: i16,
   xfer_pri: u16,
   xfer_sec: u16,
   xfer_tra: u16,
   shade:    Fx32,
}

#[derive(Debug)]
pub struct Minf
{
   env_code: u16,
   physi_id: u16,
   music_id: u16,
   msn_flag: MsnFlags,
   env_flag: EnvFlags,
   ent_flag: EntFlags,
   levelnam: String,
}

bitflags! {
   pub struct EndpointFlags: u16
   {
      const Solid       = 0x00_01;
      const SameHeight  = 0x00_02;
      const Transparent = 0x00_04;
   }
}

bitflags! {
   pub struct LineFlags: u16
   {
      const TransSide   = 0x02_00;
      const ElevVar     = 0x04_00;
      const Elevation   = 0x08_00;
      const Landscape   = 0x10_00;
      const Transparent = 0x20_00;
      const Solid       = 0x40_00;
   }
}

bitflags! {
   pub struct SideFlags: u16
   {
      const Status     = 0x00_01;
      const Panel      = 0x00_02;
      const Repair     = 0x00_04;
      const ItemUse    = 0x00_08;
      const Lighted    = 0x00_10;
      const CanDestroy = 0x00_20;
      const HitOnly    = 0x00_40;
      const ItemOpt    = 0x00_80;
   }
}

bitflags! {
   pub struct EnvFlags: u16
   {
      const Vacuum     = 0x00_01;
      const Magnetic   = 0x00_02;
      const Rebellion  = 0x00_04;
      const LowGrav    = 0x00_08;
      const M1Glue     = 0x00_10;
      const LavaFloor  = 0x00_20;
      const Rebellion2 = 0x00_40;
      const Music      = 0x00_80;
      const TermPause  = 0x01_00;
      const M1Monster  = 0x02_00;
      const M1Weps     = 0x04_00;
      const NetPlay    = 0x20_00;
      const Solo       = 0x40_00;
   }
}

bitflags! {
   pub struct EntFlags: u32
   {
      const Solo    = 0x00_01;
      const CoOp    = 0x00_02;
      const Carnage = 0x00_04;
      const KTMWTB  = 0x00_08;
      const KOTH    = 0x00_10;
      const Defense = 0x00_20;
      const Rugby   = 0x00_40;
      const CTF     = 0x00_80;
   }
}

bitflags! {
   pub struct MsnFlags: u16
   {
      const Extermination = 0x00_01;
      const Exploration   = 0x00_02;
      const Retrieval     = 0x00_04;
      const Repair        = 0x00_08;
      const Rescue        = 0x00_10;
   }
}

impl fmt::Debug for Point
{
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result
   {
      write!(f, "({}, {})", self.x, self.y)
   }
}

// EOF