import os
import argparse
import subprocess
import json

# quick and dirty dependency-free script to 
# build and output reflected zig files for 
# creating definitions for use with the json defs created
# from spirv-cross

# usage:
# python spvreflect defs.json

def generate():
    print()
    parser = argparse.ArgumentParser()
    parser.add_argument('input', type=str, help="input file")
    parser.add_argument('-o', '--output', type=str, help="output file")
    args = parser.parse_args()

    infile = os.path.abspath(args.input)
    outfile = 'reflected.zig'
    if args.output is not None:
        outfile = args.output

    reflect = None

    with open(infile) as f:
        reflect = json.load(f)
        print(reflect)


    ostring = "pub const shaderTypes = @import(\"shaderTypes\");\n"
    ostring += """
pub const int = shaderTypes.int;
pub const uint = shaderTypes.uint;

pub const vec2 = shaderTypes.vec2;
pub const u8vec4 = shaderTypes.u8vec4;
pub const vec3 = shaderTypes.vec3;
pub const vec4 = shaderTypes.vec4;
pub const mat4 = shaderTypes.mat4;
pub const float = shaderTypes.float;

"""

    types = reflect['types']
    for t in types:
        name = types[t]['name'];

        if 'type.StructuredBuffer' in name:
            continue

        if name.startswith("type.StructuredBuffer"):
            name = name[len("type.StructuredBuffer"):]

        zs = f"pub const {name} = " + 'struct {\n'

        for member in types[t]['members']:
            zs += member['name'] + ':' + member['type'] + ',\n'

        zs += "};\n"

        print(zs)

        ostring += zs


    with open(outfile, 'w') as f:
        f.write(ostring)

    subprocess.run(['zig', 'fmt', outfile])

if __name__ == '__main__':
    generate()

    pass