use std::fmt::Display;

use borsh::BorshSerialize;
use mpl_token_auth_rules::utils::get_latest_revision;
use mpl_utils::{assert_signer, create_or_allocate_account_raw};
use solana_program::{
    account_info::AccountInfo, entrypoint::ProgramResult, program::invoke, program_pack::Pack,
    pubkey::Pubkey, system_program, sysvar,
};
use spl_token::state::Account;

use crate::{
    assertions::{
        assert_derivation, assert_keys_equal, assert_owned_by,
        metadata::assert_update_authority_is_correct,
    },
    error::MetadataError,
    instruction::{Context, Delegate, DelegateArgs, MetadataDelegateRole},
    pda::{find_token_record_account, PREFIX},
    processor::AuthorizationData,
    state::{
        Metadata, MetadataDelegateRecord, Operation, ProgrammableConfig, Resizable,
        TokenDelegateRole, TokenMetadataAccount, TokenRecord, TokenStandard, TokenState,
    },
    utils::{auth_rules_validate, freeze, thaw, AuthRulesValidateParams},
};

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum DelegateScenario {
    Metadata(MetadataDelegateRole),
    Token(TokenDelegateRole),
}

impl Display for DelegateScenario {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let message = match self {
            Self::Metadata(role) => match role {
                MetadataDelegateRole::Authority => "Authority".to_string(),
                MetadataDelegateRole::Collection => "Collection".to_string(),
                MetadataDelegateRole::Use => "Use".to_string(),
                MetadataDelegateRole::Update => "Update".to_string(),
            },
            Self::Token(role) => match role {
                TokenDelegateRole::Sale => "Sale".to_string(),
                TokenDelegateRole::Transfer => "Transfer".to_string(),
                TokenDelegateRole::LockedTransfer => "LockedTransfer".to_string(),
                TokenDelegateRole::Utility => "Utility".to_string(),
                TokenDelegateRole::Staking => "Staking".to_string(),
                _ => panic!("Invalid delegate role"),
            },
        };

        write!(f, "{message}")
    }
}

/// Delegates an action over an asset to a specific account.
pub fn delegate<'a>(
    program_id: &Pubkey,
    accounts: &'a [AccountInfo<'a>],
    args: DelegateArgs,
) -> ProgramResult {
    let context = Delegate::to_context(accounts)?;

    // checks if it is a TokenDelegate creation
    let delegate_args = match &args {
        // Sale
        DelegateArgs::SaleV1 {
            amount,
            authorization_data,
        } => Some((TokenDelegateRole::Sale, amount, authorization_data)),
        // Transfer
        DelegateArgs::TransferV1 {
            amount,
            authorization_data,
        } => Some((TokenDelegateRole::Transfer, amount, authorization_data)),
        // LockedTransfer
        DelegateArgs::LockedTransferV1 {
            amount,
            authorization_data,
            ..
        } => Some((
            TokenDelegateRole::LockedTransfer,
            amount,
            authorization_data,
        )),
        // Utility
        DelegateArgs::UtilityV1 {
            amount,
            authorization_data,
        } => Some((TokenDelegateRole::Utility, amount, authorization_data)),
        // Staking
        DelegateArgs::StakingV1 {
            amount,
            authorization_data,
        } => Some((TokenDelegateRole::Staking, amount, authorization_data)),
        // Standard
        DelegateArgs::StandardV1 { amount } => Some((TokenDelegateRole::Standard, amount, &None)),
        // we don't need to fail if did not find a match at this point
        _ => None,
    };

    if let Some((role, amount, authorization_data)) = delegate_args {
        // proceed with the delegate creation if we have a match
        return create_persistent_delegate_v1(
            program_id,
            context,
            &args,
            role,
            *amount,
            authorization_data,
        );
    }

    // checks if it is a MetadataDelegate creation
    let delegate_args = match &args {
        DelegateArgs::CollectionV1 { authorization_data } => {
            Some((MetadataDelegateRole::Collection, authorization_data))
        }
        DelegateArgs::UpdateV1 { authorization_data } => {
            Some((MetadataDelegateRole::Update, authorization_data))
        }
        // we don't need to fail if did not find a match at this point
        _ => None,
    };

    if let Some((role, _authorization_data)) = delegate_args {
        return create_delegate_v1(program_id, context, args, role);
    }

    // this only happens if we did not find a match
    Err(MetadataError::InvalidDelegateArgs.into())
}

/// Creates a `DelegateRole::Collection` delegate.
///
/// There can be multiple collections delegates set at any time.
fn create_delegate_v1(
    program_id: &Pubkey,
    ctx: Context<Delegate>,
    _args: DelegateArgs,
    role: MetadataDelegateRole,
) -> ProgramResult {
    // signers

    assert_signer(ctx.accounts.payer_info)?;
    assert_signer(ctx.accounts.authority_info)?;

    // ownership

    assert_owned_by(ctx.accounts.metadata_info, program_id)?;
    assert_owned_by(ctx.accounts.mint_info, &spl_token::id())?;

    // key match

    assert_keys_equal(ctx.accounts.system_program_info.key, &system_program::ID)?;
    assert_keys_equal(
        ctx.accounts.sysvar_instructions_info.key,
        &sysvar::instructions::ID,
    )?;

    // account relationships

    let metadata = Metadata::from_account_info(ctx.accounts.metadata_info)?;
    // authority must match update authority
    assert_update_authority_is_correct(&metadata, ctx.accounts.authority_info)?;

    if metadata.mint != *ctx.accounts.mint_info.key {
        return Err(MetadataError::MintMismatch.into());
    }

    let delegate_record_info = match ctx.accounts.delegate_record_info {
        Some(delegate_record_info) => delegate_record_info,
        None => {
            return Err(MetadataError::MissingTokenAccount.into());
        }
    };

    // process the delegation creation (the derivation is checked
    // by the create helper)

    let delegate_role = role.to_string();

    create_pda_account(
        program_id,
        delegate_record_info,
        ctx.accounts.delegate_info,
        ctx.accounts.mint_info,
        ctx.accounts.authority_info,
        ctx.accounts.payer_info,
        ctx.accounts.system_program_info,
        &delegate_role,
    )
}

/// Creates a presistent delegate. For non-programmable assets, this is just a wrapper over
/// spl-token 'approve' delegate.
///
/// Note that `DelegateRole::Sale` is only available for programmable assets.
fn create_persistent_delegate_v1(
    program_id: &Pubkey,
    ctx: Context<Delegate>,
    args: &DelegateArgs,
    role: TokenDelegateRole,
    amount: u64,
    authorization_data: &Option<AuthorizationData>,
) -> ProgramResult {
    // retrieving required optional accounts

    let token_info = match ctx.accounts.token_info {
        Some(token_info) => token_info,
        None => {
            return Err(MetadataError::MissingTokenAccount.into());
        }
    };

    let spl_token_program_info = match ctx.accounts.spl_token_program_info {
        Some(spl_token_program_info) => spl_token_program_info,
        None => {
            return Err(MetadataError::MissingSplTokenProgram.into());
        }
    };

    // signers

    assert_signer(ctx.accounts.payer_info)?;
    assert_signer(ctx.accounts.authority_info)?;

    // ownership

    assert_owned_by(ctx.accounts.metadata_info, program_id)?;
    assert_owned_by(ctx.accounts.mint_info, &spl_token::id())?;
    assert_owned_by(token_info, &spl_token::id())?;

    // key match

    assert_keys_equal(ctx.accounts.system_program_info.key, &system_program::ID)?;
    assert_keys_equal(
        ctx.accounts.sysvar_instructions_info.key,
        &sysvar::instructions::ID,
    )?;
    assert_keys_equal(spl_token_program_info.key, &spl_token::ID)?;

    // account relationships

    let metadata = Metadata::from_account_info(ctx.accounts.metadata_info)?;
    if metadata.mint != *ctx.accounts.mint_info.key {
        return Err(MetadataError::MintMismatch.into());
    }

    // authority must be the owner of the token account: spl-token required the
    // token owner to set a delegate
    let token = Account::unpack(&token_info.try_borrow_data()?).unwrap();
    if token.owner != *ctx.accounts.authority_info.key {
        return Err(MetadataError::IncorrectOwner.into());
    }

    // process the delegation

    // programmables assets can have delegates from any role apart from `Standard`
    match metadata.token_standard {
        Some(TokenStandard::ProgrammableNonFungible) => {
            if matches!(role, TokenDelegateRole::Standard) {
                return Err(MetadataError::InvalidDelegateRole.into());
            }

            let (mut token_record, token_record_info) = match ctx.accounts.token_record_info {
                Some(token_record_info) => {
                    let (pda_key, _) =
                        find_token_record_account(ctx.accounts.mint_info.key, token_info.key);

                    assert_keys_equal(&pda_key, token_record_info.key)?;
                    assert_owned_by(token_record_info, &crate::ID)?;

                    (
                        TokenRecord::from_account_info(token_record_info)?,
                        token_record_info,
                    )
                }
                None => {
                    // token record is required for programmable assets
                    return Err(MetadataError::MissingTokenRecord.into());
                }
            };

            // we cannot replace an existing delegate, it must be revoked first
            if token_record.delegate.is_some() {
                return Err(MetadataError::DelegateAlreadyExists.into());
            }

            // if we have a rule set, we need to store its revision; at this point,
            // we will validate that we have the correct auth rules PDA
            if let Some(ProgrammableConfig::V1 {
                rule_set: Some(rule_set),
            }) = metadata.programmable_config
            {
                // valudates that we got the correct rule set
                let authorization_rules_info = ctx
                    .accounts
                    .authorization_rules_info
                    .ok_or(MetadataError::MissingAuthorizationRules)?;
                assert_keys_equal(authorization_rules_info.key, &rule_set)?;
                assert_owned_by(authorization_rules_info, &mpl_token_auth_rules::ID)?;

                // validates auth rules program
                let authorization_rules_program_info = ctx
                    .accounts
                    .authorization_rules_program_info
                    .ok_or(MetadataError::MissingAuthorizationRulesProgram)?;
                assert_keys_equal(
                    authorization_rules_program_info.key,
                    &mpl_token_auth_rules::ID,
                )?;

                let auth_rules_validate_params = AuthRulesValidateParams {
                    mint_info: ctx.accounts.mint_info,
                    owner_info: None,
                    authority_info: None,
                    source_info: None,
                    destination_info: Some(ctx.accounts.delegate_info),
                    programmable_config: metadata.programmable_config,
                    amount,
                    auth_data: authorization_data.clone(),
                    auth_rules_info: ctx.accounts.authorization_rules_info,
                    operation: Operation::Delegate {
                        scenario: DelegateScenario::Token(role),
                    },
                    is_wallet_to_wallet: false,
                    rule_set_revision: token_record
                        .rule_set_revision
                        .map(|revision| revision as usize),
                };

                auth_rules_validate(auth_rules_validate_params)?;

                // stores the latest rule set revision
                token_record.rule_set_revision =
                    get_latest_revision(authorization_rules_info)?.map(|revision| revision as u64);
            }

            token_record.state = if matches!(role, TokenDelegateRole::Sale) {
                // when a 'Sale' delegate is set, the token state is 'Listed'
                // to restrict holder transfers
                TokenState::Listed
            } else {
                TokenState::Unlocked
            };

            token_record.locked_transfer = if matches!(role, TokenDelegateRole::LockedTransfer) {
                if let DelegateArgs::LockedTransferV1 { locked_address, .. } = args {
                    Some(*locked_address)
                } else {
                    return Err(MetadataError::InvalidDelegateArgs.into());
                }
            } else {
                None
            };

            token_record.delegate = Some(*ctx.accounts.delegate_info.key);
            token_record.delegate_role = Some(role);
            token_record.save(
                token_record_info,
                ctx.accounts.payer_info,
                ctx.accounts.system_program_info,
            )?;

            if let Some(master_edition_info) = ctx.accounts.master_edition_info {
                assert_owned_by(master_edition_info, &crate::ID)?;
                // derivation is checked on the thaw function
                thaw(
                    ctx.accounts.mint_info.clone(),
                    token_info.clone(),
                    master_edition_info.clone(),
                    spl_token_program_info.clone(),
                )?;
            } else {
                return Err(MetadataError::MissingEditionAccount.into());
            }
        }
        _ => {
            if !matches!(role, TokenDelegateRole::Standard) {
                return Err(MetadataError::InvalidDelegateRole.into());
            }
        }
    }

    // creates the spl-token delegate
    invoke(
        &spl_token::instruction::approve(
            spl_token_program_info.key,
            token_info.key,
            ctx.accounts.delegate_info.key,
            ctx.accounts.authority_info.key,
            &[],
            amount,
        )?,
        &[
            token_info.clone(),
            ctx.accounts.delegate_info.clone(),
            ctx.accounts.authority_info.clone(),
        ],
    )?;

    if matches!(
        metadata.token_standard,
        Some(TokenStandard::ProgrammableNonFungible)
    ) {
        if let Some(master_edition_info) = ctx.accounts.master_edition_info {
            freeze(
                ctx.accounts.mint_info.clone(),
                token_info.clone(),
                master_edition_info.clone(),
                spl_token_program_info.clone(),
            )?;
        } else {
            // sanity check: this should not happen at this point since the master
            // edition account is validated before the delegation
            return Err(MetadataError::MissingEditionAccount.into());
        }
    }

    Ok(())
}

fn create_pda_account<'a>(
    program_id: &Pubkey,
    delegate_record_info: &'a AccountInfo<'a>,
    delegate_info: &'a AccountInfo<'a>,
    mint_info: &'a AccountInfo<'a>,
    authority_info: &'a AccountInfo<'a>,
    payer_info: &'a AccountInfo<'a>,
    system_program_info: &'a AccountInfo<'a>,
    delegate_role: &str,
) -> ProgramResult {
    // validates the delegate derivation

    let mut signer_seeds = vec![
        PREFIX.as_bytes(),
        program_id.as_ref(),
        mint_info.key.as_ref(),
        delegate_role.as_bytes(),
        authority_info.key.as_ref(),
        delegate_info.key.as_ref(),
    ];
    let bump = &[assert_derivation(
        program_id,
        delegate_record_info,
        &signer_seeds,
    )?];
    signer_seeds.push(bump);

    if !delegate_record_info.data_is_empty() {
        return Err(MetadataError::DelegateAlreadyExists.into());
    }

    // allocate the delegate account

    create_or_allocate_account_raw(
        *program_id,
        delegate_record_info,
        system_program_info,
        payer_info,
        MetadataDelegateRecord::size(),
        &signer_seeds,
    )?;

    let pda = MetadataDelegateRecord {
        bump: bump[0],
        mint: *mint_info.key,
        delegate: *delegate_info.key,
        update_authority: *authority_info.key,
        ..Default::default()
    };
    pda.serialize(&mut *delegate_record_info.try_borrow_mut_data()?)?;

    Ok(())
}