use crate::durandal::{err::*, text::*};
use bitflags::bitflags;
use serde::Serialize;
use std::fmt;

fn read_group(b: &[u8], text: &[u8]) -> ResultS<Group>
{
   read_data! {
      12, BE in b =>
      flags = u16[0];
      ttype = u16[2];
      pdata = i16[4];
      start = u16[6] as usize;
      size  = u16[8] as usize;
      lines = u16[10];
   }

   let text  = mac_roman_conv(&text[start..start + size]);
   let flags = flag_ok!(GroupFlags, flags)?;
   let ttype = GroupType::from_repr(ttype)?;

   Ok(Group{flags, ttype, pdata, lines, text})
}

fn read_face(b: &[u8]) -> ResultS<Face>
{
   read_data! {
      6, BE in b =>
      start = u16[0] as usize;
      face  = u16[2];
      color = u16[4];
   }

   Ok(Face{start, face, color})
}

pub fn read_term(b: &[u8]) -> ResultS<(Terminal, usize)>
{
   const SIZE_GROUP: usize = 12;
   const SIZE_FACE:  usize = 6;

   read_data! {
      10, BE in b =>
      end     = u16[0] as usize;
      encoded = u16[2];
      lines   = u16[4];
      group_n = u16[6] as usize;
      face_n  = u16[8] as usize;
   }

   let encoded = encoded != 0;

   let mut groups = Vec::with_capacity(group_n);
   let mut faces  = Vec::with_capacity(face_n);

   let mut p = 10;

   let text_st = p + SIZE_GROUP * group_n + SIZE_FACE * face_n;
   let text = &b[text_st..end];
   let text = if encoded {
      fuck_string(text)
   } else {
      text.to_vec()
   };

   for _ in 0..group_n {
      groups.push(read_group(&b[p..], &text)?);
      p += SIZE_GROUP;
   }

   for _ in 0..face_n {
      faces.push(read_face(&b[p..])?);
      p += SIZE_FACE;
   }

   Ok((Terminal{lines, groups, faces}, end))
}

#[derive(Debug, Serialize)]
pub struct Terminal
{
   lines:  u16,
   groups: Vec<Group>,
   faces:  Vec<Face>,
}

#[derive(Debug, Serialize)]
pub struct Face
{
   start: usize,
   face:  u16,
   color: u16,
}

#[derive(Serialize)]
pub struct Group
{
   flags: GroupFlags,
   ttype: GroupType,
   pdata: i16,
   lines: u16,
   text:  String,
}

bitflags! {
   #[derive(Serialize)]
   pub struct GroupFlags: u16
   {
      const DrawOnRight = 1;
      const DrawCenter  = 1 << 1;
   }
}

c_enum! {
   #[derive(Debug, Serialize)]
   pub enum GroupType: u16
   {
      0  => Logon,
      1  => Unfinished,
      2  => Success,
      3  => Failure,
      4  => Info,
      5  => End,
      6  => TeleInter,
      7  => TeleIntra,
      8  => Checkpoint,
      9  => Sound,
      10 => Movie,
      11 => Track,
      12 => Pict,
      13 => Logoff,
      14 => Camera,
      15 => Static,
      16 => Tag,
   }
}

impl fmt::Debug for Group
{
   fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
   {
      write!(f, "Group{{{:?} {} {}", self.ttype, self.pdata, self.lines)?;
      if !self.text.is_empty() {
         write!(f, ";\n{}", self.text)?;
      }
      write!(f, "}}")
   }
}

// EOF