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/*
 * SPDX-License-Identifier: Apache-2.0
 */
use crate::ledgerapi::collection::*;

///
/// Ledger representing high level concept of the Fabric Blockchain network
///
/// Provides the access points for
///  - getting access to data in both world state and peer's private collections
///  - invoking chaincode on this and other networks
///
/// When a transaction is invoked, it takes place under a 'transactional context'
/// This context can be queried to provide the current transaction id, and information
/// about the identity requesting the transaction.
///
/// All operations need to be done under this transactional context, therefore
/// the context needs to be passed to obtain the Ledger instance
///
/// # Example
///
/// ```ignore
/// use fabric_contract::contract::*;
///
///
/// pub fn asset_exists(my_assset_id: String) -> Result<bool,String> {
///    let ledger = Ledger::access_ledger();
///    
///    let world = ledger.get_collection(CollectionName::World);
///
///    Ok(world.state_exists(&my_assset_id))
///
/// }
/// ``` 
pub struct Ledger {}

impl Ledger {

    /// Get the Ledger based on the current transactional context
    ///
    /// The Tranasctional Context is available via the [Transaction API](../../transaction/struct.Transaction.html)
    ///
    pub fn access_ledger() -> Ledger {
        Ledger::new()
    }

    // Private new function
    fn new() -> Ledger {
        Ledger {}
    }

    /// Return the collection based on the name
    ///
    /// The collection provides access to the put & get Fabric
    /// semantics of the underlying world state, or private data
    /// that is specified by the Collection name.
    ///
    /// # Example
    /// ```ignore
    /// use fabric_contract::contract::*;
    /// let ledger = Ledger::access_ledger();
    ///
    /// // get the collectin that is backed by the World State
    /// let world = ledger.get_collection(CollectionName::World);  
    ///
    /// // get the collection that is backed by the Organization's Implicity Private Data Collection
    /// let orgs_collection = ledger.get_collection(CollectionName::Organization(String::from("org1")));
    ///    
    /// // get the collection that is backed by the named Private Data Collection
    /// let private_collection = ledger.get_collection(CollectionName::Private(String::from("my_private_details")));
    /// ```
    pub fn get_collection(&self, name: CollectionName) -> Collection {
        Collection::new(name)
    }
}