generate.jl

function generate(json)
    x = JSON3.read(json)
    structs = []
    generate!(structs, x)
    return generatejulia(structs)
end

struct Struct
    name::String
    names::Vector{Symbol}
    types::Vector{Any}
end

generate!(structs, x) = generate!(structs, "Root", x)

function generate!(structs, name, x::JSON3.Object)
    isempty(x) && return Any
    names = Symbol[]
    types = []
    for (k, v) in x
        push!(names, k)
        push!(types, generate!(structs, titlecase(String(k)), v))
    end
    push!(structs, Struct(name, names, types))
    return name
end

generate!(structs, name, x::JSON3.Array{T}) where {T} = "Vector{$(isempty(x) ? generate!(structs, string(name, "s"), T) : generate!(structs, string(name, "s"), x[1]))}"

generate!(structs, k, x::T) where {T} = T
generate!(structs, k, ::Type{T}) where {T} = T
generate!(structs, k, ::Type{JSON3.Object}) = Any

function generatejulia(structs)
    io = IOBuffer()
    Base.write(io, """
    using StructTypes, JSON3
    """)
    for x in structs
        fields = join(["$name::$type" for (name, type) in zip(x.names, x.types)], "\n")
        Base.write(io, """
mutable struct $(x.name)
    $fields
    $(x.name)() = new()
end

StructTypes.StructType(::Type{$(x.name)}) = StructTypes.Mutable()
        """)
    end
    return String(take!(io))
end