import json
from collections import defaultdict

print("package properties")
print("// This code has been generated with the genProps.py script. Do not modify\n\n")

print("import \"bufio\"")
print("import \"io\"")
print("import . \"badat.dev/maeqtt/v2/mqtt/types\"")

TYPE_TO_GOTYPE = {
            "Byte": "byte",
            "Two Byte Integer": "uint16",
            "Four Byte Integer": "uint32",
            "Binary Data": "[]byte",
            "UTF-8 Encoded String": "string",
            "Variable Byte Integer": "uint32",
        }
TYPE_DECODE_CODE = {
        "Byte": "val, err := r.ReadByte()",
        "Two Byte Integer": "val, err := DecodeUint16(r)",
        "Four Byte Integer": "val, err := DecodeUint32(r)",
        "Binary Data": "val, err := DecodeBinaryData(r)",
        "UTF-8 Encoded String": "val, err := DecodeUTF8String(r)",
        "Variable Byte Integer": "val, err := DecodeVariableByteInt(r)"
}

TYPE_WRITE_CODE = {
        "Byte": "(func () error {_, err := w.Write([]byte{*p.Value}); return err})()",
        "Two Byte Integer": "WriteUint16(w, *p.Value)",
        "Four Byte Integer": "WriteUint32(w, *p.Value)",
        "Binary Data": "WriteBinaryData(w, *p.Value)",
        "UTF-8 Encoded String": "WriteUTF8String(w, *p.Value)",
        "Variable Byte Integer": "WriteVariableByteInt(w, *p.Value)"
}

applicationToProp = defaultdict(lambda: [])

with open("./properties.json") as f:
    properties = json.load(f)

for prop in properties:
    prop["name"] = "".join(prop["name"].split(" "))

for prop in properties:
    for application in prop["appliesTo"]:
        applicationToProp[application].append(prop)
        
    val = prop["val"]
    name= prop["name"]
    if val == "38":
        #needs manual handling
        continue

    gotype = TYPE_TO_GOTYPE[prop["type"]]
    godecode = TYPE_DECODE_CODE[prop["type"]]
    gowrite = TYPE_WRITE_CODE[prop["type"]]

    print("""
type {name} struct {{
	Value *{gotype}
}}

func (p {name}) id() int {{
	return {val}
}}

func (p *{name}) parse(r *bufio.Reader) error {{
        {godecode}
	if err != nil {{
		return err
	}}
        p.Value = &val
        return nil
}}

func (p {name}) hasValue() bool {{
    return p.Value != nil
}}

func (p {name}) write(w io.Writer) error {{
        return {gowrite}
}}
    """.format(name= name, gotype = gotype, gowrite = gowrite, godecode = godecode, val = val
        ))

for k,v in applicationToProp.items():
    if k == "Will Properties":
        arrName = "WillProperties"
    else:
        arrName = k.lower().capitalize() + "PacketProperties"

    print("type", arrName, "struct {")

    for prop in v:
        print(prop["name"], prop["name"])
    print("}")
    print(f"func (p *{arrName}) ArrayOf() []Property {{")
    print("return []Property {")
    for prop in v:
        propName = prop["name"]
        print(f"&p.{propName},")
    print("}")
    print("}")