use near_sdk::{env, near, AccountId, PanicOnDefault};

#[near(contract_state)]
#[derive(PanicOnDefault)]
pub struct Registry {
    owner_id: AccountId,
    entries: Vec<(AccountId, String)>,
}

#[near]
impl Registry {
    #[init]
    pub fn new(owner_id: AccountId) -> Self {
        Self { owner_id, entries: Vec::new() }
    }

    pub fn set(&mut self, account_id: AccountId, value: String) {
        self.assert_owner();
        if value.len() > 256 { env::panic_str("Value too long"); }
        if let Some(entry) = self.entries.iter_mut().find(|(id, _)| id == &account_id) {
            entry.1 = value;
        } else {
            self.entries.push((account_id, value));
        }
    }

    pub fn get(&self, account_id: AccountId) -> Option<String> {
        self.entries.iter().find(|(id, _)| id == &account_id).map(|(_, value)| value.clone())
    }

    pub fn remove(&mut self, account_id: AccountId) -> bool {
        self.assert_owner();
        if let Some(index) = self.entries.iter().position(|(id, _)| id == &account_id) {
            self.entries.swap_remove(index);
            true
        } else { false }
    }

    pub fn count(&self) -> u32 { self.entries.len() as u32 }

    fn assert_owner(&self) {
        if env::predecessor_account_id() != self.owner_id { env::panic_str("Owner only"); }
    }
}