egdata-manifests-parser 0.1.0

use byteorder::{LittleEndian, ReadBytesExt};
use hex;
use log::debug;
use serde::{Deserialize, Serialize};
use std::io::{Read, Seek, SeekFrom};

use crate::error::Error;
use crate::parser::reader::ReadExt;
use crate::types::chunk::{ChunkDataList, ChunkPart};

#[derive(Debug, Clone, Serialize, Deserialize, Default)]
pub struct FileManifest {
    #[serde(serialize_with = "trim_null_chars")]
    pub filename: String,
    pub symlink_target: String,
    pub sha_hash: String,
    pub file_meta_flags: u8,
    #[serde(serialize_with = "vector_trim_null_chars")]
    pub install_tags: Vec<String>,
    pub chunk_parts: Vec<ChunkPart>,
    pub file_size: i64,
    #[serde(skip_serializing_if = "String::is_empty")]
    pub mime_type: String,
}

#[derive(Debug, Clone, Serialize, Deserialize, Default)]
pub struct FileManifestList {
    pub data_size: u32,
    pub data_version: u8,
    pub count: u32,
    pub file_manifest_list: Vec<FileManifest>,
}

fn trim_null_chars<S>(value: &String, serializer: S) -> Result<S::Ok, S::Error>
where
    S: serde::Serializer,
{
    let trimmed = value.trim_end_matches('\0');
    serializer.serialize_str(trimmed)
}

fn vector_trim_null_chars<S>(value: &Vec<String>, serializer: S) -> Result<S::Ok, S::Error>
where
    S: serde::Serializer,
{
    let trimmed: Vec<String> = value
        .iter()
        .map(|s| s.trim_end_matches('\0').to_string())
        .collect();
    trimmed.serialize(serializer)
}

// File meta flags from .NET implementation
#[repr(u8)]
pub enum EFileMetaFlags {
    None = 0,
    ReadOnly = 1 << 0,
    Compressed = 1 << 1,
    UnixExecutable = 1 << 2,
}

impl FileManifest {
    pub fn is_readonly(&self) -> bool {
        self.file_meta_flags & EFileMetaFlags::ReadOnly as u8 != 0
    }

    pub fn is_compressed(&self) -> bool {
        self.file_meta_flags & EFileMetaFlags::Compressed as u8 != 0
    }

    pub fn is_unix_executable(&self) -> bool {
        self.file_meta_flags & EFileMetaFlags::UnixExecutable as u8 != 0
    }
}

impl FileManifestList {
    pub fn read<R: Read + Seek>(rdr: &mut R, chunk_list: &ChunkDataList) -> Result<Self, Error> {
        let start_pos = rdr.stream_position()?;
        debug!(
            "\nReading file list at position: {} (0x{:x})",
            start_pos, start_pos
        );

        // Read data size (uint32 in Go)
        let data_size = rdr.read_u32::<LittleEndian>()?;
        debug!("  Data size: {} (0x{:x})", data_size, data_size);

        // Validate data size
        if data_size == 0 || data_size > 1024 * 1024 * 1024 {
            // 1GB max
            return Err(Error::Invalid(format!(
                "Invalid data size: {} (0x{:x}). Must be between 1 and 1GB",
                data_size, data_size
            )));
        }

        // Read data version (uint8 in Go)
        let data_version = rdr.read_u8()?;
        debug!("  Data version: {} (0x{:x})", data_version, data_version);

        // Validate data version
        if data_version > 2 {
            return Err(Error::Invalid(format!(
                "Invalid data version: {} (0x{:x}). Must be 0, 1, or 2",
                data_version, data_version
            )));
        }

        // Read count (uint32 in Go)
        let count = rdr.read_u32::<LittleEndian>()?;
        debug!("  Count: {} (0x{:x})", count, count);

        // Validate count
        if count > 1_000_000 {
            // Reasonable max file count
            return Err(Error::Invalid(format!(
                "Invalid count: {} (0x{:x}). Must be less than 1,000,000",
                count, count
            )));
        }

        // Initialize file list with capacity
        let mut files = Vec::with_capacity(count as usize);

        // Read filenames in batch
        debug!("\nReading filenames...");
        for _ in 0..count {
            let mut file = FileManifest::default();
            file.filename = rdr.fstring()?;
            files.push(file);
        }

        // Read symlink targets in batch
        debug!("\nReading symlink targets...");
        for i in 0..count {
            files[i as usize].symlink_target = rdr.fstring()?;
        }

        // Read SHA hashes in batch
        debug!("\nReading file hashes...");
        for i in 0..count {
            let mut hash = [0u8; 20];
            rdr.read_exact(&mut hash)?;
            files[i as usize].sha_hash = hex::encode(hash);
        }

        // Read file meta flags in batch
        debug!("\nReading file meta flags...");
        for i in 0..count {
            files[i as usize].file_meta_flags = rdr.read_u8()?;
        }

        // Read install tags in batch
        debug!("\nReading install tags...");
        for i in 0..count {
            files[i as usize].install_tags = rdr.fstring_array()?;
        }

        // Read chunk parts in batch
        debug!("\nReading chunk parts...");
        let mut total_chunk_parts = 0;
        let mut total_chunk_size = 0i64;
        for i in 0..count {
            let chunk_count = rdr.read_u32::<LittleEndian>()?;
            let pos = rdr.stream_position()?;
            debug!(
                "File {}: Reading {} chunk parts at position {}",
                i, chunk_count, pos
            );

            // Validate chunk count - use a more reasonable limit based on remaining data
            let remaining_bytes = data_size as u64 - (pos - start_pos);
            let max_possible_chunks = remaining_bytes / 32; // Each chunk part is ~32 bytes
            if chunk_count > max_possible_chunks as u32 {
                debug!(
                    "   Warning: Invalid chunk count ({}) for file {} at position {}, skipping.",
                    chunk_count, i, pos
                );
                files[i as usize].chunk_parts = Vec::new();
                continue;
            }

            // Read chunks
            let mut chunks = Vec::with_capacity(chunk_count as usize);
            let mut file_chunk_size = 0i64;
            let mut valid_chunks = 0;

            for j in 0..chunk_count {
                let chunk_pos = rdr.stream_position()?;
                match ChunkPart::read(rdr, &chunk_list.chunk_lookup, &chunk_list.elements) {
                    Ok(chunk) => {
                        file_chunk_size += chunk.size as i64;
                        chunks.push(chunk);
                        valid_chunks += 1;
                        if j == 0 || j == chunk_count - 1 {
                            debug!(
                                "  Chunk part {}: size={}, offset={}, parent={} (at pos {})",
                                j,
                                chunks[j as usize].size,
                                chunks[j as usize].offset,
                                chunks[j as usize].parent_guid,
                                chunk_pos
                            );
                        }
                    }
                    Err(e) => {
                        debug!(
              "   Warning: Failed to read chunk part {} for file {}: {}. Skipping remaining chunks.",
              j, i, e
            );
                        break;
                    }
                }
            }

            if valid_chunks > 0 {
                total_chunk_parts += valid_chunks;
                total_chunk_size += file_chunk_size;
                files[i as usize].chunk_parts = chunks;
                files[i as usize].file_size = file_chunk_size; // Calculate file size from chunks
            } else {
                debug!(
                    "   Warning: No valid chunks found for file {}, skipping.",
                    i
                );
                files[i as usize].chunk_parts = Vec::new();
            }
        }

        // Handle version 2+ specific data
        if data_version >= 2 {
            debug!("\nReading version 2+ specific data...");
            for _ in 0..count {
                // Skip unknown array
                let array_size = rdr.read_u32::<LittleEndian>()?;
                rdr.seek(SeekFrom::Current(array_size as i64 * 16))?;
            }

            // Read MIME types
            for i in 0..count {
                files[i as usize].mime_type = rdr.fstring()?;
            }

            // Skip unknown data
            for _ in 0..count {
                rdr.seek(SeekFrom::Current(32))?;
            }
        }

        debug!(
            "Total chunk parts: {}, Total chunk size: {} bytes",
            total_chunk_parts, total_chunk_size
        );

        let end_pos = rdr.stream_position()?;
        let bytes_read = end_pos - start_pos;

        // Validate we read the expected amount of data
        if bytes_read != data_size as u64 {
            debug!(
                "Warning: Read {} bytes but expected {} bytes",
                bytes_read, data_size
            );
        }

        Ok(Self {
            data_size,
            data_version,
            count,
            file_manifest_list: files,
        })
    }
}