use anyhow::Result;
use aws_sdk_route53::types::{Change, ChangeAction, ChangeBatch, ResourceRecordSet};
// Needed until try_collect is stable, see <https://github.com/rust-lang/rust/issues/94047>
use itertools::Itertools;

use crate::route53::Route53;

pub enum ApplyMode {
    DryRun,
    Apply,
}

impl ApplyMode {
    pub async fn apply<C, R, I>(
        &self,
        aws_context: &C,
        zone_id: &str,
        remove_records: R,
        insert_records: I,
    ) -> Result<()>
    where
        C: Route53,
        R: IntoIterator<Item = ResourceRecordSet>,
        I: IntoIterator<Item = ResourceRecordSet>,
    {
        match self {
            ApplyMode::DryRun => dry_run(zone_id, remove_records, insert_records).await,
            ApplyMode::Apply => apply(aws_context, zone_id, remove_records, insert_records).await,
        }
    }
}

async fn dry_run<R, I>(zone_id: &str, remove_records: R, insert_records: I) -> Result<()>
where
    R: IntoIterator<Item = ResourceRecordSet>,
    I: IntoIterator<Item = ResourceRecordSet>,
{
    let remove_records: Vec<_> = remove_records.into_iter().collect();
    let insert_records: Vec<_> = insert_records.into_iter().collect();

    println!("ZONE: {}", zone_id);
    println!("REMOVE: {:#?}", remove_records);
    println!("INSERT: {:#?}", insert_records);

    Ok(())
}

async fn apply<C, R, I>(
    aws_context: &C,
    zone_id: &str,
    remove_records: R,
    insert_records: I,
) -> Result<()>
where
    C: Route53,
    R: IntoIterator<Item = ResourceRecordSet>,
    I: IntoIterator<Item = ResourceRecordSet>,
{
    let remove_records = remove_records.into_iter().map(|record| {
        Change::builder()
            .action(ChangeAction::Delete) // <--
            .resource_record_set(record)
            .build()
    });
    let insert_records = insert_records.into_iter().map(|record| {
        Change::builder()
            .action(ChangeAction::Create) // <--
            .resource_record_set(record)
            .build()
    });

    let change_records: Vec<_> = remove_records.chain(insert_records).try_collect()?;
    if !change_records.is_empty() {
        let change_batch = ChangeBatch::builder()
            .set_changes(Some(change_records))
            .build()?;

        aws_context
            .route53()
            .change_resource_record_sets()
            .hosted_zone_id(zone_id)
            .change_batch(change_batch)
            .send()
            .await?;
    }

    Ok(())
}