/* This file is part of DarkFi (https://dark.fi)
 *
 * Copyright (C) 2020-2024 Dyne.org foundation
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

use darkfi_money_contract::model::CoinAttributes;
use darkfi_sdk::{
    bridgetree,
    bridgetree::Hashable,
    crypto::{
        note::AeadEncryptedNote, pasta_prelude::*, pedersen_commitment_u64, poseidon_hash, Keypair,
        MerkleNode, Nullifier, PublicKey, SecretKey,
    },
    pasta::pallas,
};
use darkfi_serial::{async_trait, SerialDecodable, SerialEncodable};
use log::debug;
use rand::rngs::OsRng;

use darkfi::{
    zk::{halo2::Value, Proof, ProvingKey, Witness, ZkCircuit},
    zkas::ZkBinary,
    Result,
};

use crate::model::{Dao, DaoProposal, DaoVoteParams, DaoVoteParamsInput, VecAuthCallCommit};

#[derive(SerialEncodable, SerialDecodable)]
pub struct DaoVoteNote {
    pub vote_option: bool,
    pub yes_vote_blind: pallas::Scalar,
    // yes_vote_value = vote_option * all_vote_value
    pub all_vote_value: u64,
    pub all_vote_blind: pallas::Scalar,
}

pub struct DaoVoteInput {
    pub secret: SecretKey,
    pub note: darkfi_money_contract::client::MoneyNote,
    pub leaf_position: bridgetree::Position,
    pub merkle_path: Vec<MerkleNode>,
    pub signature_secret: SecretKey,
}

// Inside ZKproof, check proposal is correct.
pub struct DaoVoteCall {
    pub inputs: Vec<DaoVoteInput>,
    pub vote_option: bool,
    pub yes_vote_blind: pallas::Scalar,
    pub vote_keypair: Keypair,
    pub proposal: DaoProposal,
    pub dao: Dao,
    pub current_day: u64,
}

impl DaoVoteCall {
    pub fn make(
        self,
        burn_zkbin: &ZkBinary,
        burn_pk: &ProvingKey,
        main_zkbin: &ZkBinary,
        main_pk: &ProvingKey,
    ) -> Result<(DaoVoteParams, Vec<Proof>)> {
        debug!(target: "dao", "build()");
        let mut proofs = vec![];

        let gov_token_blind = pallas::Base::random(&mut OsRng);

        let mut inputs = vec![];
        let mut all_vote_value = 0;
        let mut all_vote_blind = pallas::Scalar::from(0);

        for input in self.inputs {
            let value_blind = pallas::Scalar::random(&mut OsRng);

            all_vote_value += input.note.value;
            all_vote_blind += value_blind;

            let signature_public = PublicKey::from_secret(input.signature_secret);

            // Note from the previous output
            let note = input.note;
            let leaf_pos: u64 = input.leaf_position.into();

            let prover_witnesses = vec![
                Witness::Base(Value::known(input.secret.inner())),
                Witness::Base(Value::known(note.serial)),
                Witness::Base(Value::known(pallas::Base::ZERO)),
                Witness::Base(Value::known(pallas::Base::ZERO)),
                Witness::Base(Value::known(pallas::Base::from(note.value))),
                Witness::Base(Value::known(note.token_id.inner())),
                Witness::Scalar(Value::known(all_vote_blind)),
                Witness::Base(Value::known(gov_token_blind)),
                Witness::Uint32(Value::known(leaf_pos.try_into().unwrap())),
                Witness::MerklePath(Value::known(input.merkle_path.clone().try_into().unwrap())),
                Witness::Base(Value::known(input.signature_secret.inner())),
            ];

            let public_key = PublicKey::from_secret(input.secret);
            let coin = CoinAttributes {
                public_key,
                value: note.value,
                token_id: note.token_id,
                serial: note.serial,
                spend_hook: pallas::Base::ZERO,
                user_data: pallas::Base::ZERO,
            }
            .to_coin();

            let merkle_root = {
                let position: u64 = input.leaf_position.into();
                let mut current = MerkleNode::from(coin.inner());
                for (level, sibling) in input.merkle_path.iter().enumerate() {
                    let level = level as u8;
                    current = if position & (1 << level) == 0 {
                        MerkleNode::combine(level.into(), &current, sibling)
                    } else {
                        MerkleNode::combine(level.into(), sibling, &current)
                    };
                }
                current
            };

            let token_commit = poseidon_hash([note.token_id.inner(), gov_token_blind]);
            assert_eq!(self.dao.gov_token_id, note.token_id);

            let nullifier = poseidon_hash([input.secret.inner(), coin.inner()]);

            let vote_commit = pedersen_commitment_u64(note.value, all_vote_blind);
            let vote_commit_coords = vote_commit.to_affine().coordinates().unwrap();

            let (sig_x, sig_y) = signature_public.xy();

            let public_inputs = vec![
                nullifier,
                *vote_commit_coords.x(),
                *vote_commit_coords.y(),
                token_commit,
                merkle_root.inner(),
                sig_x,
                sig_y,
            ];

            let circuit = ZkCircuit::new(prover_witnesses, burn_zkbin);
            debug!(target: "dao", "input_proof Proof::create()");
            let input_proof = Proof::create(burn_pk, &[circuit], &public_inputs, &mut OsRng)
                .expect("DAO::vote() proving error!");
            proofs.push(input_proof);

            let input = DaoVoteParamsInput {
                nullifier: Nullifier::from(nullifier),
                vote_commit,
                merkle_root,
                signature_public,
            };
            inputs.push(input);
        }

        let token_commit = poseidon_hash([self.dao.gov_token_id.inner(), gov_token_blind]);

        let dao_proposer_limit = pallas::Base::from(self.dao.proposer_limit);
        let dao_quorum = pallas::Base::from(self.dao.quorum);
        let dao_approval_ratio_quot = pallas::Base::from(self.dao.approval_ratio_quot);
        let dao_approval_ratio_base = pallas::Base::from(self.dao.approval_ratio_base);
        let (dao_pub_x, dao_pub_y) = self.dao.public_key.xy();

        let vote_option = self.vote_option as u64;
        assert!(vote_option == 0 || vote_option == 1);

        let yes_vote_commit =
            pedersen_commitment_u64(vote_option * all_vote_value, self.yes_vote_blind);
        let yes_vote_commit_coords = yes_vote_commit.to_affine().coordinates().unwrap();

        let all_vote_commit = pedersen_commitment_u64(all_vote_value, all_vote_blind);
        let all_vote_commit_coords = all_vote_commit.to_affine().coordinates().unwrap();

        let current_day = pallas::Base::from(self.current_day);
        let prover_witnesses = vec![
            // proposal params
            Witness::Base(Value::known(self.proposal.auth_calls.commit())),
            Witness::Base(Value::known(pallas::Base::from(self.proposal.creation_day))),
            Witness::Base(Value::known(pallas::Base::from(self.proposal.duration_days))),
            Witness::Base(Value::known(self.proposal.user_data)),
            Witness::Base(Value::known(self.proposal.blind)),
            // DAO params
            Witness::Base(Value::known(dao_proposer_limit)),
            Witness::Base(Value::known(dao_quorum)),
            Witness::Base(Value::known(dao_approval_ratio_quot)),
            Witness::Base(Value::known(dao_approval_ratio_base)),
            Witness::Base(Value::known(self.dao.gov_token_id.inner())),
            Witness::Base(Value::known(dao_pub_x)),
            Witness::Base(Value::known(dao_pub_y)),
            Witness::Base(Value::known(self.dao.bulla_blind)),
            // Vote
            Witness::Base(Value::known(pallas::Base::from(vote_option))),
            Witness::Scalar(Value::known(self.yes_vote_blind)),
            // Total number of gov tokens allocated
            Witness::Base(Value::known(pallas::Base::from(all_vote_value))),
            Witness::Scalar(Value::known(all_vote_blind)),
            // gov token
            Witness::Base(Value::known(gov_token_blind)),
            // time checks
            Witness::Base(Value::known(current_day)),
        ];

        assert_eq!(self.dao.to_bulla(), self.proposal.dao_bulla);
        let proposal_bulla = self.proposal.to_bulla();

        let public_inputs = vec![
            token_commit,
            proposal_bulla.inner(),
            *yes_vote_commit_coords.x(),
            *yes_vote_commit_coords.y(),
            *all_vote_commit_coords.x(),
            *all_vote_commit_coords.y(),
            current_day,
        ];

        let circuit = ZkCircuit::new(prover_witnesses, main_zkbin);

        debug!(target: "dao", "main_proof = Proof::create()");
        let main_proof = Proof::create(main_pk, &[circuit], &public_inputs, &mut OsRng)
            .expect("DAO::vote() proving error!");
        proofs.push(main_proof);

        let note = DaoVoteNote {
            vote_option: self.vote_option,
            yes_vote_blind: self.yes_vote_blind,
            all_vote_value,
            all_vote_blind,
        };
        let enc_note =
            AeadEncryptedNote::encrypt(&note, &self.vote_keypair.public, &mut OsRng).unwrap();

        let params =
            DaoVoteParams { token_commit, proposal_bulla, yes_vote_commit, note: enc_note, inputs };

        Ok((params, proofs))
    }
}
