infinite-rs 0.13.2

//! Tag datablock specifying the section for tag structs.

use byteorder::{LE, ReadBytesExt};
use num_enum::TryFromPrimitive;
use std::io::BufRead;

use crate::common::errors::TagError;
use crate::common::extensions::Enumerable;
use crate::{Result, TagFile};

#[derive(Default, Debug, TryFromPrimitive, PartialEq, Eq)]
#[repr(u16)]
/// Location where the data referenced in the tag block is found.
pub enum TagSectionType {
    #[default]
    /// Inside the tag header (metadata)
    Header,
    /// Inside the main parent tag.
    TagData,
    /// Inside resource child tag.
    ResourceData,
    /// Inside the "external" resource (for instance, bitmaps or havok data)
    ActualResource,
}

#[derive(Default, Debug)]
/// Tag data metadata block containing data on where the binary section is located.
pub struct TagDataBlock {
    /// The size of the data block entry in bytes.
    pub entry_size: u32,
    /// How many unused bytes come before the offset.
    padding: u16,
    /// Where the data block is stored.
    pub section_type: TagSectionType,
    /// Offset of where the data is stored from the start of the tag file.
    pub offset: u64,
}

impl Enumerable for TagDataBlock {
    fn read<R: BufRead>(&mut self, reader: &mut R) -> Result<()> {
        self.entry_size = reader.read_u32::<LE>()?;
        self.padding = reader.read_u16::<LE>()?;
        self.section_type = TagSectionType::try_from(reader.read_u16::<LE>()?)
            .map_err(TagError::InvalidTagSection)?;
        self.offset = reader.read_u64::<LE>()?;
        Ok(())
    }
}

impl TagDataBlock {
    pub(crate) fn get_offset(&self, tag_info: &TagFile) -> u64 {
        let section_offset = match self.section_type {
            TagSectionType::TagData | TagSectionType::Header => 0,
            TagSectionType::ResourceData => tag_info.header.data_size,
            TagSectionType::ActualResource => {
                tag_info.header.data_size + tag_info.header.resource_size
            }
        };
        u64::from(section_offset) + self.offset
    }
}