use std::env;
use std::fs;
use std::iter::once;
use std::path::Path;

use indexmap::IndexMap;
use itertools::Itertools;

// The list is taken from https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-instance.html#cfn-ec2-instance-instancetype
const INSTANT_TYPES: &str = "a1.2xlarge | a1.4xlarge | a1.large | a1.medium | a1.metal | a1.xlarge | c1.medium | c1.xlarge | c3.2xlarge | c3.4xlarge | c3.8xlarge | c3.large | c3.xlarge | c4.2xlarge | c4.4xlarge | c4.8xlarge | c4.large | c4.xlarge | c5.12xlarge | c5.18xlarge | c5.24xlarge | c5.2xlarge | c5.4xlarge | c5.9xlarge | c5.large | c5.metal | c5.xlarge | c5a.12xlarge | c5a.16xlarge | c5a.24xlarge | c5a.2xlarge | c5a.4xlarge | c5a.8xlarge | c5a.large | c5a.xlarge | c5ad.12xlarge | c5ad.16xlarge | c5ad.24xlarge | c5ad.2xlarge | c5ad.4xlarge | c5ad.8xlarge | c5ad.large | c5ad.xlarge | c5d.12xlarge | c5d.18xlarge | c5d.24xlarge | c5d.2xlarge | c5d.4xlarge | c5d.9xlarge | c5d.large | c5d.metal | c5d.xlarge | c5n.18xlarge | c5n.2xlarge | c5n.4xlarge | c5n.9xlarge | c5n.large | c5n.xlarge | c6g.12xlarge | c6g.16xlarge | c6g.2xlarge | c6g.4xlarge | c6g.8xlarge | c6g.large | c6g.medium | c6g.metal | c6g.xlarge | c6gd.12xlarge | c6gd.16xlarge | c6gd.2xlarge | c6gd.4xlarge | c6gd.8xlarge | c6gd.large | c6gd.medium | c6gd.metal | c6gd.xlarge | cc1.4xlarge | cc2.8xlarge | cg1.4xlarge | cr1.8xlarge | d2.2xlarge | d2.4xlarge | d2.8xlarge | d2.xlarge | f1.16xlarge | f1.2xlarge | f1.4xlarge | g2.2xlarge | g2.8xlarge | g3.16xlarge | g3.4xlarge | g3.8xlarge | g3s.xlarge | g4dn.12xlarge | g4dn.16xlarge | g4dn.2xlarge | g4dn.4xlarge | g4dn.8xlarge | g4dn.metal | g4dn.xlarge | h1.16xlarge | h1.2xlarge | h1.4xlarge | h1.8xlarge | hi1.4xlarge | hs1.8xlarge | i2.2xlarge | i2.4xlarge | i2.8xlarge | i2.xlarge | i3.16xlarge | i3.2xlarge | i3.4xlarge | i3.8xlarge | i3.large | i3.metal | i3.xlarge | i3en.12xlarge | i3en.24xlarge | i3en.2xlarge | i3en.3xlarge | i3en.6xlarge | i3en.large | i3en.metal | i3en.xlarge | inf1.24xlarge | inf1.2xlarge | inf1.6xlarge | inf1.xlarge | m1.large | m1.medium | m1.small | m1.xlarge | m2.2xlarge | m2.4xlarge | m2.xlarge | m3.2xlarge | m3.large | m3.medium | m3.xlarge | m4.10xlarge | m4.16xlarge | m4.2xlarge | m4.4xlarge | m4.large | m4.xlarge | m5.12xlarge | m5.16xlarge | m5.24xlarge | m5.2xlarge | m5.4xlarge | m5.8xlarge | m5.large | m5.metal | m5.xlarge | m5a.12xlarge | m5a.16xlarge | m5a.24xlarge | m5a.2xlarge | m5a.4xlarge | m5a.8xlarge | m5a.large | m5a.xlarge | m5ad.12xlarge | m5ad.16xlarge | m5ad.24xlarge | m5ad.2xlarge | m5ad.4xlarge | m5ad.8xlarge | m5ad.large | m5ad.xlarge | m5d.12xlarge | m5d.16xlarge | m5d.24xlarge | m5d.2xlarge | m5d.4xlarge | m5d.8xlarge | m5d.large | m5d.metal | m5d.xlarge | m5dn.12xlarge | m5dn.16xlarge | m5dn.24xlarge | m5dn.2xlarge | m5dn.4xlarge | m5dn.8xlarge | m5dn.large | m5dn.xlarge | m5n.12xlarge | m5n.16xlarge | m5n.24xlarge | m5n.2xlarge | m5n.4xlarge | m5n.8xlarge | m5n.large | m5n.xlarge | m6g.12xlarge | m6g.16xlarge | m6g.2xlarge | m6g.4xlarge | m6g.8xlarge | m6g.large | m6g.medium | m6g.metal | m6g.xlarge | m6gd.12xlarge | m6gd.16xlarge | m6gd.2xlarge | m6gd.4xlarge | m6gd.8xlarge | m6gd.large | m6gd.medium | m6gd.metal | m6gd.xlarge | p2.16xlarge | p2.8xlarge | p2.xlarge | p3.16xlarge | p3.2xlarge | p3.8xlarge | p3dn.24xlarge | p4d.24xlarge | r3.2xlarge | r3.4xlarge | r3.8xlarge | r3.large | r3.xlarge | r4.16xlarge | r4.2xlarge | r4.4xlarge | r4.8xlarge | r4.large | r4.xlarge | r5.12xlarge | r5.16xlarge | r5.24xlarge | r5.2xlarge | r5.4xlarge | r5.8xlarge | r5.large | r5.metal | r5.xlarge | r5a.12xlarge | r5a.16xlarge | r5a.24xlarge | r5a.2xlarge | r5a.4xlarge | r5a.8xlarge | r5a.large | r5a.xlarge | r5ad.12xlarge | r5ad.16xlarge | r5ad.24xlarge | r5ad.2xlarge | r5ad.4xlarge | r5ad.8xlarge | r5ad.large | r5ad.xlarge | r5d.12xlarge | r5d.16xlarge | r5d.24xlarge | r5d.2xlarge | r5d.4xlarge | r5d.8xlarge | r5d.large | r5d.metal | r5d.xlarge | r5dn.12xlarge | r5dn.16xlarge | r5dn.24xlarge | r5dn.2xlarge | r5dn.4xlarge | r5dn.8xlarge | r5dn.large | r5dn.xlarge | r5n.12xlarge | r5n.16xlarge | r5n.24xlarge | r5n.2xlarge | r5n.4xlarge | r5n.8xlarge | r5n.large | r5n.xlarge | r6g.12xlarge | r6g.16xlarge | r6g.2xlarge | r6g.4xlarge | r6g.8xlarge | r6g.large | r6g.medium | r6g.metal | r6g.xlarge | r6gd.12xlarge | r6gd.16xlarge | r6gd.2xlarge | r6gd.4xlarge | r6gd.8xlarge | r6gd.large | r6gd.medium | r6gd.metal | r6gd.xlarge | t1.micro | t2.2xlarge | t2.large | t2.medium | t2.micro | t2.nano | t2.small | t2.xlarge | t3.2xlarge | t3.large | t3.medium | t3.micro | t3.nano | t3.small | t3.xlarge | t3a.2xlarge | t3a.large | t3a.medium | t3a.micro | t3a.nano | t3a.small | t3a.xlarge | t4g.2xlarge | t4g.large | t4g.medium | t4g.micro | t4g.nano | t4g.small | t4g.xlarge | u-12tb1.metal | u-18tb1.metal | u-24tb1.metal | u-6tb1.metal | u-9tb1.metal | x1.16xlarge | x1.32xlarge | x1e.16xlarge | x1e.2xlarge | x1e.32xlarge | x1e.4xlarge | x1e.8xlarge | x1e.xlarge | z1d.12xlarge | z1d.2xlarge | z1d.3xlarge | z1d.6xlarge | z1d.large | z1d.metal | z1d.xlarge";

fn to_enum_value(r#type: &str) -> String {
    let (family, size) = r#type.split('.').collect_tuple().unwrap();
    let family = family.to_uppercase().replace("-", "_");
    let size = match size {
        "32xlarge" => "32XLarge",
        "24xlarge" => "24XLarge",
        "18xlarge" => "18XLarge",
        "16xlarge" => "16XLarge",
        "12xlarge" => "12XLarge",
        "10xlarge" => "10XLarge",
        "9xlarge" => "9XLarge",
        "8xlarge" => "8XLarge",
        "6xlarge" => "6XLarge",
        "4xlarge" => "4XLarge",
        "3xlarge" => "3XLarge",
        "2xlarge" => "2XLarge",
        "xlarge" => "XLarge",
        "large" => "Large",
        "medium" => "Medium",
        "small" => "Small",
        "micro" => "Micro",
        "nano" => "Nano",
        "metal" => "Metal",
        other => panic!("instance type `{}` is not supported yet", other),
    };

    format!("{}_{}", family, size)
}

fn main() {
    let types = INSTANT_TYPES
        .split(" | ")
        .map(|r#type| (r#type, to_enum_value(r#type)))
        .collect::<IndexMap<_, _>>();

    let instance_types = once(String::from("#[allow(non_camel_case_types)]"))
        .chain(once(String::from(
            "#[derive(Clone, Copy, Debug, Hash, PartialEq)]",
        )))
        .chain(once(String::from("pub enum InstanceType {")))
        .chain(types.values().map(|r#type| format!("    {},", r#type)))
        .chain(once(String::from("}\n")))
        .fold(String::new(), |text, item| format!("{}\n{}", text, item));

    let instance_types = once(String::from("impl InstanceType {"))
        .chain(once(String::from("    pub fn as_str(&self) -> &str {")))
        .chain(once(String::from("        match self {")))
        .chain(
            types
                .iter()
                .map(|(s, e)| format!("            Self::{} => \"{}\",", e, s)),
        )
        .chain(once(String::from("        }")))
        .chain(once(String::from("    }")))
        .chain(once(String::new()))
        .chain(once(String::from(
            "    pub fn from_text(text: &str) -> Option<Self> {",
        )))
        .chain(once(String::from("        match text {")))
        .chain(
            types
                .iter()
                .map(|(s, e)| format!("            \"{}\" => Some(Self::{}),", s, e)),
        )
        .chain(once(String::from("            _ => None,")))
        .chain(once(String::from("        }")))
        .chain(once(String::from("    }")))
        .chain(once(String::from("}\n")))
        .fold(instance_types, |text, item| format!("{}\n{}", text, item));

    let out = env::var_os("OUT_DIR").unwrap();
    let instance_type_rs = Path::new(&out).join("instance_type.rs");
    fs::write(instance_type_rs, instance_types).unwrap();
}