using JSON

# We'll use these two structs to demonstrate encoding and
# decoding of custom types below.
struct Response1
    page::Int
    fruits::Vector{String}
end

# Only fields with values will be encoded/decoded in JSON.
struct Response2
    page::Int
    fruits::Vector{String}
end

function main()
    # First we'll look at encoding basic data types to
    # JSON strings. Here are some examples for atomic values.
    bolB = JSON.json(true)
    println(bolB)

    intB = JSON.json(1)
    println(intB)

    fltB = JSON.json(2.34)
    println(fltB)

    strB = JSON.json("gopher")
    println(strB)

    # And here are some for arrays and dictionaries, which encode
    # to JSON arrays and objects as you'd expect.
    slcD = ["apple", "peach", "pear"]
    slcB = JSON.json(slcD)
    println(slcB)

    mapD = Dict("apple" => 5, "lettuce" => 7)
    mapB = JSON.json(mapD)
    println(mapB)

    # The JSON package can automatically encode your
    # custom data types. It will include all fields
    # in the encoded output.
    res1D = Response1(1, ["apple", "peach", "pear"])
    res1B = JSON.json(res1D)
    println(res1B)

    res2D = Response2(1, ["apple", "peach", "pear"])
    res2B = JSON.json(res2D)
    println(res2B)

    # Now let's look at decoding JSON data into Julia
    # values. Here's an example for a generic data structure.
    byt = """{"num":6.13,"strs":["a","b"]}"""

    # We need to parse the JSON string into a Julia structure.
    # This `Dict{String,Any}` will hold a dictionary of strings
    # to arbitrary data types.
    dat = JSON.parse(byt)
    println(dat)

    # We can access values in the decoded data directly.
    num = dat["num"]
    println(num)

    # Accessing nested data is straightforward.
    strs = dat["strs"]
    str1 = strs[1]
    println(str1)

    # We can also decode JSON into custom data types.
    # This has the advantages of adding additional
    # type-safety to our programs.
    str = """{"page": 1, "fruits": ["apple", "peach"]}"""
    res = JSON.parse(str, Response2)
    println(res)
    println(res.fruits[1])

    # In the examples above we always used strings as
    # intermediates between the data and JSON representation.
    # We can also stream JSON encodings directly to IO streams.
    d = Dict("apple" => 5, "lettuce" => 7)
    JSON.print(stdout, d)
    println()
end

main()