class AwsCurl

# File lib/rawscurl.rb, line 37
def self.getSignatureKey key, dateStamp, regionName, serviceName
    kDate = OpenSSL::HMAC.digest('sha256', "AWS4" + key, dateStamp)
    kRegion = OpenSSL::HMAC.digest('sha256', kDate, regionName)
    kService = OpenSSL::HMAC.digest('sha256', kRegion, serviceName)
    kSigning = OpenSSL::HMAC.digest('sha256', kService, "aws4_request")

    kSigning
end

# File lib/rawscurl.rb, line 12
def self.make_request(
    method: "GET",
    service: "execute-api",
    region:,
    uri:,
    headers: "",
    data: "",
    access_key:,
    secret_key:,
    security_token: "",
    data_binary: "",
    connection_id:
)
    uri_dict = url_path_to_dict(uri)
    host = uri_dict.host
    query = uri_dict.query
    #canonical_uri = CGI.escape(uri_dict.path)
    canonical_uri = uri_dict.path + "/" + CGI.escape("@connections") + "/" + CGI.escape(connection_id)
    port = uri_dict.port

    # puts "host: #{host}"
    # puts "query: #{query}"
    # puts "canonical_uri: #{canonical_uri}"
    # puts "port: #{port}"

    def self.getSignatureKey key, dateStamp, regionName, serviceName
        kDate = OpenSSL::HMAC.digest('sha256', "AWS4" + key, dateStamp)
        kRegion = OpenSSL::HMAC.digest('sha256', kDate, regionName)
        kService = OpenSSL::HMAC.digest('sha256', kRegion, serviceName)
        kSigning = OpenSSL::HMAC.digest('sha256', kService, "aws4_request")
    
        kSigning
    end

    def self.sha256_hash(val)
        Digest::SHA256.hexdigest(val)
    end

    def self.sha256_hash_for_binary_data(val)
        Digest::SHA256.hexdigest(val)
    end

    t = Time.now.utc
    amzdate = t.strftime('%Y%m%dT%H%M%SZ')
    datestamp = t.strftime('%Y%m%d')

    canonical_querystring = uri_dict.normalize.query.nil? ? "" : uri_dict.normalize.query
    fullhost = port.nil? ? host + ":" + port : host

    canonical_headers = "host:#{fullhost}\n" +
        "x-amz-date:#{amzdate}\n"

    unless security_token&.empty?
        canonical_headers += "x-amz-security-token:#{security_token}\n"
    end

    signed_headers = "host;x-amz-date"

    unless security_token&.empty?
        signed_headers += ";x-amz-security-token"
    end

    payload_hash = data_binary&.empty? ? sha256_hash(data) : sha256_hash_for_binary_data(data)

    canonical_request = method + "\n" +
        canonical_uri + "\n" +
        canonical_querystring + "\n" +
        canonical_headers + "\n" +
        signed_headers + "\n" +
        payload_hash

    # puts "CANONICAL REQUEST = #{canonical_request}"

    algorithm = "AWS4-HMAC-SHA256"
    credential_scope = datestamp + "/" +
        region + "/" + 
        service + "/" +
        "aws4_request"

    string_to_sign = algorithm + "\n" +
        amzdate + "\n" +
        credential_scope + "\n" +
        sha256_hash(canonical_request)

    # puts "STRING TO SIGN = #{string_to_sign}"

    signing_key = getSignatureKey(secret_key, datestamp, region, service)

    encoded = string_to_sign.encode("utf-8")
    signature = OpenSSL::HMAC.hexdigest('sha256', signing_key, encoded)

    # puts "Signature: #{signature}"

    authorization_header = algorithm + " " +
        "Credential=" + access_key + "/" + credential_scope + ", " +
        "SignedHeaders=" + signed_headers + ", " +
        "Signature=" + signature

    # puts "AUTHORIZATION HEADER: #{authorization_header}"

    if security_token&.empty?
        headers = {
            "Authorization": authorization_header,
            "x-amz-date": amzdate,
            #"x-amz-security-token": security_token,
            "x-amz-content-sha256": payload_hash
        }
    else
        headers = {
            "Authorization": authorization_header,
            "x-amz-date": amzdate,
            "x-amz-security-token": security_token,
            "x-amz-content-sha256": payload_hash
        }
    end

    # puts "Headers: #{headers}"

    send_request(uri_dict, data, headers, method, connection_id)
end

# File lib/rawscurl.rb, line 133
def self.send_request(uri, data, headers, method, connection_id)
    # puts "************* SENDING REQUEST ***************"
    # puts "URI: #{uri}"
    # puts "DATA: #{data}"
    # puts "HEADERS: #{headers}"
    # puts "METHOD: #{method}"

    if method == "GET"
        req = Net::HTTP::Get.new(uri.to_s + "/@connections" + "/" + connection_id, initheader = headers)
    elsif method == "POST"
        req = Net::HTTP::Post.new(uri.to_s + "/@connections" + "/" + connection_id, initheader = headers)
        req.body = data
    elsif method == "DELETE"
        req = Net::HTTP::Delete.new(uri.to_s + "/@connections" + "/" + connection_id, initheader = headers)
    end
    https = Net::HTTP.new(uri.host, uri.port)
    https.use_ssl = true

    res = https.request(req)

    result = res.body
    status_code = res.code
    # puts "HTTP Status code: #{status_code}, (200=Connected, 204=Disconnected, 400=Invalid connectionId, 410=Gone)"
    # puts res

    # puts "************* REQUEST SENT ******************"
    return status_code, result
end

# File lib/rawscurl.rb, line 46
def self.sha256_hash(val)
    Digest::SHA256.hexdigest(val)
end

# File lib/rawscurl.rb, line 50
def self.sha256_hash_for_binary_data(val)
    Digest::SHA256.hexdigest(val)
end

# File lib/rawscurl.rb, line 8
def self.url_path_to_dict(path)
    URI.parse(path)
end