use crate::server::{attrs::Attr, blobref::BlobRef};
use rand::{thread_rng, Rng};
use serde::{Deserialize, Serialize};
use time::OffsetDateTime;

#[derive(Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub(super) struct Anchor {
    rand: u64,
    #[serde(with = "time::serde::rfc3339")]
    created_at: OffsetDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
pub(super) struct Patch {
    pub anchor: BlobRef,
    pub changes: Vec<Change>,
    #[serde(with = "time::serde::rfc3339")]
    created_at: OffsetDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
// #[allow(clippy::enum_variant_names)]
pub(super) enum Change {
    AddChunk {
        blobref: BlobRef,
        offset: u64,
        size: usize,
    },
    SetAttr(Attr),
}

impl Anchor {
    pub(super) fn new() -> Self {
        Self {
            rand: thread_rng().gen(),
            created_at: OffsetDateTime::now_utc(),
        }
    }
}

impl Patch {
    pub(super) fn new(anchor: BlobRef) -> Self {
        Self {
            anchor,
            changes: Vec::new(),
            created_at: OffsetDateTime::now_utc(),
        }
    }

    pub(super) fn add_change(&mut self, change: Change) {
        self.changes.push(change);
    }
}