module embed_file

// EmbedFileData encapsulates functionality for the `$embed_file()` compile time call.
pub struct EmbedFileData {
    apath            string
    compression_type string
mut:
    compressed        &u8 = unsafe { nil }
    uncompressed      &u8 = unsafe { nil }
    free_compressed   bool
    free_uncompressed bool
pub:
    len  int
    path string
}

pub fn (ed EmbedFileData) str() string {
    return 'embed_file.EmbedFileData{ len: ${ed.len}, path: "${ed.path}", apath: "${ed.apath}", uncompressed: ${ptr_str(ed.uncompressed)} }'
}

@[unsafe]
pub fn (mut ed EmbedFileData) free() {
    unsafe {
        ed.path.free()
        ed.apath.free()
        ed.compression_type.free()
        if ed.free_compressed {
            free(ed.compressed)
            ed.compressed = &u8(nil)
        }
        if ed.free_uncompressed {
            free(ed.uncompressed)
            ed.uncompressed = &u8(nil)
        }
    }
}

pub fn (original &EmbedFileData) to_string() string {
    unsafe {
        mut ed := &EmbedFileData(original)
        the_copy := &u8(memdup(ed.data(), ed.len))
        return the_copy.vstring_with_len(ed.len)
    }
}

pub fn (original &EmbedFileData) to_bytes() []u8 {
    unsafe {
        mut ed := &EmbedFileData(original)
        the_copy := memdup(ed.data(), ed.len)
        return the_copy.vbytes(ed.len)
    }
}

pub fn (mut ed EmbedFileData) data() &u8 {
    if ed.uncompressed != unsafe { nil } {
        return ed.uncompressed
    }
    if ed.uncompressed == unsafe { nil } && ed.compressed != unsafe { nil } {
        decoder := g_embed_file_decoders.decoders[ed.compression_type] or {
            panic('EmbedFileData error: unknown compression of "${ed.path}": "${ed.compression_type}"')
        }
        compressed := unsafe { ed.compressed.vbytes(ed.len) }
        decompressed := decoder.decompress(compressed) or {
            panic('EmbedFileData error: decompression of "${ed.path}" failed: ${err}')
        }
        unsafe {
            ed.uncompressed = &u8(memdup(decompressed.data, ed.len))
        }
    } else {
        $if !freestanding {
            reload_from_file_at_runtime(mut ed)
        }
    }
    return ed.uncompressed
}

//////////////////////////////////////////////////////////////////////////////
// EmbedFileIndexEntry is used internally by the V compiler when you compile a
// program that uses $embed_file('file.bin') in -prod mode.
// V will generate a static index of all embedded files, and will call the
// find_index_entry_by_path over the index and the relative paths of the embeds.
// Note: these are public on purpose, to help -usecache.
pub struct EmbedFileIndexEntry {
    id   int
    path string
    algo string
    data &u8 = unsafe { nil }
}

// find_index_entry_by_path is used internally by the V compiler:
@[markused]
pub fn find_index_entry_by_path(start voidptr, path string, algo string) &EmbedFileIndexEntry {
    unsafe {
        mut x := &EmbedFileIndexEntry(start)
        for x.id >= 0 && x.data != 0 && (x.algo != algo || x.path != path) {
            x++
        }
        $if trace_embed_file ? {
            eprintln('>> v.embed_file find_index_entry_by_path ${ptr_str(start)}, id: ${x.id}, path: "${path}", algo: "${algo}" => ${ptr_str(x)}')
        }
        return x
    }
}