amethystate-core 0.9.1

use crate::AmeBackend;
use crate::primitives::map_core::{ReactiveMapKey, ReactiveMapValue};
use crate::{MapChange, ReactiveMapCore};

use serde::de::DeserializeOwned;
use std::fmt::Display;
use std::str::FromStr;
use std::sync::Arc;
use uuid::Uuid;

pub fn map_get<B, K, V>(backend: &B, path: &str, key: &K) -> Result<Option<V>, B::Error>
where
    B: AmeBackend,
    K: Display,
    V: DeserializeOwned,
{
    backend.get(&format!("{}.{}", path, key))
}

pub fn map_contains_key<B, K, V>(backend: &B, path: &str, key: &K) -> Result<bool, B::Error>
where
    B: AmeBackend,
    K: Display,
    V: DeserializeOwned,
{
    map_get::<B, K, V>(backend, path, key).map(|v| v.is_some())
}

pub fn map_entries<B, K, V>(backend: &B, path: &str) -> Result<Vec<(K, V)>, B::Error>
where
    B: AmeBackend,
    K: FromStr,
    V: DeserializeOwned + Default,
{
    let prefix = format!("{}.", path);
    let kvs = backend.scan_prefix(&prefix)?;

    let mut results = Vec::new();

    for (full_path, raw) in kvs {
        if let Some(key_str) = full_path.strip_prefix(&prefix)
            && let Ok(k) = K::from_str(key_str)
            && let Ok(v) = backend.decode::<V>(&raw)
        {
            results.push((k, v));
        }
    }

    Ok(results)
}

pub fn map_len<B>(backend: &B, path: &str) -> Result<usize, B::Error>
where
    B: AmeBackend,
{
    backend
        .scan_prefix(&format!("{}.", path))
        .map(|kvs| kvs.len())
}

pub fn map_set_existing<B, K, V>(
    backend: &B,
    core: &ReactiveMapCore<K, V>,
    path: Arc<str>,
    key: K,
    value: &V,
    notify_after_commit: bool,
    source: Option<Uuid>,
) -> Result<(), B::Error>
where
    B: AmeBackend,
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    let full_path = format!("{}.{}", path, key);
    let old_value = match backend.get::<V>(&full_path)? {
        Some(old_value) => old_value,
        None => return Err(backend.key_not_found(key.to_string())),
    };

    let change = MapChange::Update {
        key,
        old_value,
        new_value: value.clone(),
        source,
    };

    map_apply_change(backend, core, path, change, notify_after_commit)
}

pub fn map_set_or_create<B, K, V>(
    backend: &B,
    core: &ReactiveMapCore<K, V>,
    path: Arc<str>,
    key: K,
    value: &V,
    notify_after_commit: bool,
    source: Option<Uuid>,
) -> Result<(), B::Error>
where
    B: AmeBackend,
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    let full_path = format!("{}.{}", path, key);
    let old_value = backend.get::<V>(&full_path)?;
    let change = if let Some(old_value) = old_value {
        MapChange::Update {
            key,
            old_value,
            new_value: value.clone(),
            source,
        }
    } else {
        MapChange::Insert {
            key,
            value: value.clone(),
            source,
        }
    };

    map_apply_change(backend, core, path, change, notify_after_commit)
}

pub fn map_remove<B, K, V>(
    backend: &B,
    core: &ReactiveMapCore<K, V>,
    path: Arc<str>,
    key: K,
    notify_after_commit: bool,
    source: Option<Uuid>,
) -> Result<Option<V>, B::Error>
where
    B: AmeBackend,
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    let exists = core.cache.lock().unwrap().contains_key(&key);
    if !exists {
        return Ok(None);
    }

    let full_path = format!("{}.{}", path, key);
    let old_value = backend.get::<V>(&full_path)?;
    if let Some(old_value) = old_value {
        let change = MapChange::Remove {
            key,
            old_value: old_value.clone(),
            source,
        };
        map_apply_change(backend, core, path, change, notify_after_commit)?;
        Ok(Some(old_value))
    } else {
        core.cache.lock().unwrap().remove(&key);
        Ok(None)
    }
}

pub fn map_clear<B, K, V>(
    backend: &B,
    core: &ReactiveMapCore<K, V>,
    path: Arc<str>,
    notify_after_commit: bool,
    source: Option<Uuid>,
) -> Result<(), B::Error>
where
    B: AmeBackend,
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    map_apply_change(
        backend,
        core,
        path,
        MapChange::Clear { source },
        notify_after_commit,
    )
}

pub fn map_apply_change<B, K, V>(
    backend: &B,
    core: &ReactiveMapCore<K, V>,
    path: Arc<str>,
    change: MapChange<K, V>,
    notify_after_commit: bool,
) -> Result<(), B::Error>
where
    B: AmeBackend,
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    let context_path: Arc<str> = match change.key() {
        Some(key) => format!("{}.{}", path, key).into(),
        None => path.clone(),
    };

    let processed = core
        .run_interceptors(context_path, change)
        .map_err(|_| backend.intercepted())?;

    match &processed {
        MapChange::Insert { key, value, .. }
        | MapChange::Update {
            key,
            new_value: value,
            ..
        } => {
            backend.set_with_source(&format!("{}.{}", path, key), value, processed.source())?;
        }
        MapChange::Remove { key, .. } => {
            backend.delete_with_source(&format!("{}.{}", path, key), processed.source())?;
        }
        MapChange::Clear { .. } => {
            let prefix = format!("{}.", path);
            let kvs = backend.scan_prefix(&prefix)?;
            for (full_path, _) in kvs {
                backend.delete_with_source(&full_path, processed.source())?;
            }
        }
    }

    map_apply_remote_change(core, &processed);
    if notify_after_commit {
        core.notify(&processed);
    }

    Ok(())
}

pub fn map_apply_remote_change<K, V>(core: &ReactiveMapCore<K, V>, change: &MapChange<K, V>)
where
    K: ReactiveMapKey,
    V: ReactiveMapValue,
{
    let mut keys = core.cache.lock().unwrap();
    match change {
        MapChange::Insert { key, value, .. }
        | MapChange::Update {
            key,
            new_value: value,
            ..
        } => {
            keys.insert(key.clone(), value.clone());
        }
        MapChange::Remove { key, .. } => {
            keys.remove(key);
        }
        MapChange::Clear { .. } => {
            keys.clear();
        }
    }
}