use std::{fs::File, io::Read, path::Path};

use super::header::Header;
use crate::lumps::{LinedefLump, Lump, LumpType, VertexLump};
use crate::types::{Linedef, Vertex};
use crate::utils::{read_ascii, read_i16_le, read_u32_le, validate_wad};

pub struct WADFile {
    pub path: String,
    pub wad_id: String,
    pub num_lumps: u32,
    pub dir_offset: u32,
    pub directory: Vec<Lump>,
    pub data: Vec<u8>,
}

impl WADFile {
    pub fn new(path: String) -> Self {
        if !(validate_wad(path.as_str()).unwrap()) {
            panic!();
        }

        let file_path = Path::new(path.as_str());
        let mut wad_file = File::open(file_path).unwrap();
        let file_size = wad_file.metadata().unwrap().len() as usize;
        let mut file_buffer: Vec<u8> = Vec::with_capacity(file_size);

        wad_file.read_to_end(&mut file_buffer).unwrap();

        let wad_header = Header::read_data(&file_buffer[0..12]);

        let mut lump_dir: Vec<Lump> = Vec::with_capacity(wad_header.num_lumps as usize);
        let offset = wad_header.dir_offset;

        for entry in 0..wad_header.num_lumps {
            let startpos = (offset + 16 * entry) as usize;
            let lump_offset = read_u32_le(&file_buffer[startpos..startpos + 4]);
            let size = read_u32_le(&file_buffer[startpos + 4..startpos + 8]);
            let name = read_ascii(&file_buffer[startpos + 8..startpos + 16]);
            let lump_type = match name.as_str() {
                "VERTEXES" => LumpType::Vertex,
                "LINEDEFS" => LumpType::Linedef,
                _ => LumpType::Unknown,
            };
            lump_dir.push(Lump {
                name,
                offset: lump_offset,
                lump_type,
                size,
            });
        }

        Self {
            path,
            wad_id: wad_header.wad_id,
            num_lumps: wad_header.num_lumps,
            dir_offset: wad_header.dir_offset,
            directory: lump_dir,
            data: file_buffer,
        }
    }

    pub fn get_vertex_lump(&self, lump: &Lump) -> VertexLump {
        let lump_offset = lump.offset as usize;
        let lump_size = lump.size as usize;
        let lump_data = &self.data[lump_offset..lump_offset + lump_size];
        let lump_entries: usize = lump_size / 4;
        let mut vertexes: Vec<Vertex> = Vec::with_capacity(lump_entries);

        for entry in 0..lump_entries {
            let startpos = entry * 4;
            let vertex_x = read_i16_le(&lump_data[startpos..startpos + 2]);
            let vertex_y = read_i16_le(&lump_data[startpos + 2..startpos + 4]);

            vertexes.push(Vertex {
                x: vertex_x,
                y: vertex_y,
            });
        }

        VertexLump { vertexes }
    }

    pub fn get_linedef_lump(&self, lump: &Lump) -> LinedefLump {
        let lump_offset = lump.offset as usize;
        let lump_size = lump.size as usize;
        let lump_data = &self.data[lump_offset..lump_offset + lump_size];
        let lump_entries = lump_size / 14;
        let mut linedefs: Vec<Linedef> = Vec::with_capacity(lump_entries);

        for entry in 0..lump_entries {
            let startpos = entry * 14;
            let vertex1 = read_i16_le(&lump_data[startpos..startpos + 2]);
            let vertex2 = read_i16_le(&lump_data[startpos + 2..startpos + 4]);
            let flags = read_i16_le(&lump_data[startpos + 4..startpos + 6]);
            let special = read_i16_le(&lump_data[startpos + 6..startpos + 8]);
            let tag = read_i16_le(&lump_data[startpos + 8..startpos + 10]);
            let front_sidedef = read_i16_le(&lump_data[startpos + 10..startpos + 12]);
            let back_sidedef = read_i16_le(&lump_data[startpos + 12..startpos + 14]);

            linedefs.push(Linedef {
                vertex1,
                vertex2,
                flags,
                special,
                tag,
                front_sidedef,
                back_sidedef,
            });
        }

        LinedefLump { linedefs }
    }
}