use soroban_sdk::xdr::{ContractEvent, GeneralizedTransactionSet, LedgerCloseMeta, LedgerEntry, LedgerEntryChange, LedgerKey, TransactionEnvelope, TransactionMeta, TransactionPhase, TransactionResultMeta, TransactionResultResult, TxSetComponent};

/// Represents all of the entry changes that happened in the
/// ledger close.
#[derive(Clone)]
#[allow(missing_docs)]
pub struct EntryChanges {
    pub state: Vec<LedgerEntry>,
    pub removed: Vec<LedgerKey>,
    pub updated: Vec<LedgerEntry>,
    pub created: Vec<LedgerEntry>,
}

/// Ledger meta reader. 
/// 
/// Aids developers in dealing with raw XDR structures.
/// 
pub struct MetaReader<'a>(&'a soroban_sdk::xdr::LedgerCloseMeta);

#[allow(missing_docs)]
impl<'a> MetaReader<'a> {
    pub fn new(meta: &'a LedgerCloseMeta) -> Self {
        Self(meta)
    }

    pub fn ledger_sequence(&self) -> u32 {
        match &self.0 {
            LedgerCloseMeta::V1(v1) => v1.ledger_header.header.ledger_seq,
            LedgerCloseMeta::V0(v0) => v0.ledger_header.header.ledger_seq,
        }
    }

    pub fn ledger_timestamp(&self) -> u64 {
        match &self.0 {
            LedgerCloseMeta::V1(v1) => v1.ledger_header.header.scp_value.close_time.0,
            LedgerCloseMeta::V0(v0) => v0.ledger_header.header.scp_value.close_time.0,
        }
    }

    // todo: add handles for other entries.

    pub fn envelopes(&self) -> Vec<TransactionEnvelope> {
        match &self.0 {
            LedgerCloseMeta::V0(v0) => {
                v0.tx_set.txs.to_vec()
            },
            LedgerCloseMeta::V1(v1) => {
                let phases = match &v1.tx_set {
                    GeneralizedTransactionSet::V1(v1) => &v1.phases,
                };

                let mut envelopes = Vec::new();

                for phase in phases.iter() {
                    match phase {
                        TransactionPhase::V0(v0) => {
                            for txset_component in v0.iter() {
                                match txset_component {
                                    TxSetComponent::TxsetCompTxsMaybeDiscountedFee(
                                        txset_maybe_discounted_fee,
                                    ) => {
                                        for tx_envelope in txset_maybe_discounted_fee.txs.to_vec() {
                                            envelopes.push(tx_envelope)
                                        }
                                    }
                                }
                            }
                        }
                    }
                }

                envelopes
            }
        }
    }

    pub fn envelopes_with_meta(&self) -> Vec<(&TransactionEnvelope, &TransactionResultMeta)> {
        let mut composed = Vec::new();
        
        match &self.0 {
            LedgerCloseMeta::V0(_) => (), // todo
            LedgerCloseMeta::V1(v1) => {
                let phases = match &v1.tx_set {
                    GeneralizedTransactionSet::V1(v1) => &v1.phases,
                };

                for phase in phases.iter() {
                    match phase {
                        TransactionPhase::V0(v0) => {
                            for txset_component in v0.iter() {
                                match txset_component {
                                    TxSetComponent::TxsetCompTxsMaybeDiscountedFee(
                                        txset_maybe_discounted_fee,
                                    ) => {
                                        for (idx, tx_envelope) in txset_maybe_discounted_fee.txs.iter().enumerate() {
                                            let txmeta = &v1.tx_processing[idx];
                                            
                                            composed.push((tx_envelope, txmeta))
                                        }
                                    }
                                }
                            }
                        }
                    }
                }

            }
        };

        composed
    }


    pub fn tx_processing(&self) -> Vec<TransactionResultMeta> {
        match &self.0 {
            LedgerCloseMeta::V1(v1) => {
                v1.tx_processing.to_vec()
            },
            LedgerCloseMeta::V0(v0) => {
                v0.tx_processing.to_vec()
            },
        }
    }

    pub fn v1_success_ledger_entries(&self) -> EntryChanges {
        let mut state_entries = Vec::new();
        let mut removed_entries = Vec::new();
        let mut updated_entries = Vec::new();
        let mut created_entries = Vec::new();

        match &self.0 {
            LedgerCloseMeta::V0(_) => (),
            LedgerCloseMeta::V1(v1) => {
                for tx_processing in v1.tx_processing.iter() {
                    let result = &tx_processing.result.result.result;
                    let success = match result {
                        TransactionResultResult::TxSuccess(_) => true,
                        TransactionResultResult::TxFeeBumpInnerSuccess(_) => true,
                        _ => false
                    };

                    if success {
                        match &tx_processing.tx_apply_processing {
                            TransactionMeta::V3(meta) => {
                                let ops = &meta.operations;

                                for operation in ops.clone().into_vec() {
                                    for change in operation.changes.0.iter() {
                                        match &change {
                                            LedgerEntryChange::State(state) => {
                                                state_entries.push(state.clone())
                                            }
                                            LedgerEntryChange::Created(created) => {
                                                created_entries.push(created.clone())
                                            }
                                            LedgerEntryChange::Updated(updated) => {
                                                updated_entries.push(updated.clone())
                                            }
                                            LedgerEntryChange::Removed(removed) => {
                                                removed_entries.push(removed.clone())
                                            }
                                        };
                                    }
                                }
                            }
                            _ => (),
                        }
                    }
                }
            }
        };

        EntryChanges {
            state: state_entries,
            removed: removed_entries,
            updated: updated_entries,
            created: created_entries,
        }
    }

    pub fn v1_ledger_entries(&self) -> EntryChanges {
        let mut state_entries = Vec::new();
        let mut removed_entries = Vec::new();
        let mut updated_entries = Vec::new();
        let mut created_entries = Vec::new();

        match &self.0 {
            LedgerCloseMeta::V0(_) => (),
            LedgerCloseMeta::V1(v1) => {
                for tx_processing in v1.tx_processing.iter() {
                    match &tx_processing.tx_apply_processing {
                        TransactionMeta::V3(meta) => {
                            let ops = &meta.operations;

                            for operation in ops.clone().into_vec() {
                                for change in operation.changes.0.iter() {
                                    match &change {
                                        LedgerEntryChange::State(state) => {
                                            state_entries.push(state.clone())
                                        }
                                        LedgerEntryChange::Created(created) => {
                                            created_entries.push(created.clone())
                                        }
                                        LedgerEntryChange::Updated(updated) => {
                                            updated_entries.push(updated.clone())
                                        }
                                        LedgerEntryChange::Removed(removed) => {
                                            removed_entries.push(removed.clone())
                                        }
                                    };
                                }
                            }
                        }
                        _ => (),
                    }
                }
            }
        };

        EntryChanges {
            state: state_entries,
            removed: removed_entries,
            updated: updated_entries,
            created: created_entries,
        }
    }

    pub fn soroban_events(&self) -> Vec<ContractEvent> {
        let mut events = Vec::new();
        
        for result in self.tx_processing() {
            if let TransactionMeta::V3(v3) = &result.tx_apply_processing {
                if let Some(soroban) = &v3.soroban_meta {
                    for event in soroban.events.iter() {
                        events.push(event.clone())
                    }
                }
            }
        }

        events
    }
}