// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the snarkOS library.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use super::{CurrentNetwork, Developer};

use snarkvm::prelude::{
    query::Query,
    store::{helpers::memory::ConsensusMemory, ConsensusStore},
    Address,
    Identifier,
    Locator,
    PrivateKey,
    Process,
    ProgramID,
    Value,
    VM,
};

use anyhow::{anyhow, bail, Result};
use clap::Parser;
use colored::Colorize;
use std::str::FromStr;

/// Executes an Aleo program function.
#[derive(Debug, Parser)]
pub struct Execute {
    /// The program identifier.
    program_id: ProgramID<CurrentNetwork>,
    /// The function name.
    function: Identifier<CurrentNetwork>,
    /// The function inputs.
    inputs: Vec<Value<CurrentNetwork>>,
    /// The private key used to generate the execution.
    #[clap(short, long)]
    private_key: String,
    /// The endpoint to query node state from.
    #[clap(short, long)]
    query: String,
    /// The priority fee in microcredits.
    #[clap(long)]
    priority_fee: Option<u64>,
    /// The record to spend the fee from.
    #[clap(short, long)]
    record: Option<String>,
    /// The endpoint used to broadcast the generated transaction.
    #[clap(short, long, conflicts_with = "dry_run")]
    broadcast: Option<String>,
    /// Performs a dry-run of transaction generation.
    #[clap(short, long, conflicts_with = "broadcast")]
    dry_run: bool,
    /// Store generated deployment transaction to a local file.
    #[clap(long)]
    store: Option<String>,
}

impl Execute {
    /// Executes an Aleo program function with the provided inputs.
    #[allow(clippy::format_in_format_args)]
    pub fn parse(self) -> Result<String> {
        // Ensure that the user has specified an action.
        if !self.dry_run && self.broadcast.is_none() && self.store.is_none() {
            bail!("❌ Please specify one of the following actions: --broadcast, --dry-run, --store");
        }

        // Specify the query
        let query = Query::from(&self.query);

        // Retrieve the private key.
        let private_key = PrivateKey::from_str(&self.private_key)?;

        let locator = Locator::<CurrentNetwork>::from_str(&format!("{}/{}", self.program_id, self.function))?;
        println!("📦 Creating execution transaction for '{}'...\n", &locator.to_string().bold());

        // Generate the execution transaction.
        let transaction = {
            // Initialize an RNG.
            let rng = &mut rand::thread_rng();

            // Initialize the VM.
            let store = ConsensusStore::<CurrentNetwork, ConsensusMemory<CurrentNetwork>>::open(None)?;
            let vm = VM::from(store)?;

            // Load the program and it's imports into the process.
            load_program(&self.query, &mut vm.process().write(), &self.program_id)?;

            // Prepare the fee.
            let fee_record = match &self.record {
                Some(record_string) => Some(Developer::parse_record(&private_key, record_string)?),
                None => None,
            };
            let priority_fee = self.priority_fee.unwrap_or(0);

            // Create a new transaction.
            vm.execute(
                &private_key,
                (self.program_id, self.function),
                self.inputs.iter(),
                fee_record,
                priority_fee,
                Some(query),
                rng,
            )?
        };

        // Check if the public balance is sufficient.
        if self.record.is_none() {
            // Fetch the public balance.
            let address = Address::try_from(&private_key)?;
            let public_balance = Developer::get_public_balance(&address, &self.query)?;

            // Check if the public balance is sufficient.
            let storage_cost = transaction
                .execution()
                .ok_or_else(|| anyhow!("The transaction does not contain an execution"))?
                .size_in_bytes()?;

            // Calculate the base fee.
            // This fee is the minimum fee required to pay for the transaction,
            // excluding any finalize fees that the execution may incur.
            let base_fee = storage_cost.saturating_add(self.priority_fee.unwrap_or(0));

            // If the public balance is insufficient, return an error.
            if public_balance < base_fee {
                bail!(
                    "❌ The public balance of {} is insufficient to pay the base fee for `{}`",
                    public_balance,
                    locator.to_string().bold()
                );
            }
        }

        println!("✅ Created execution transaction for '{}'", locator.to_string().bold());

        // Determine if the transaction should be broadcast, stored, or displayed to user.
        Developer::handle_transaction(self.broadcast, self.dry_run, self.store, transaction, locator.to_string())
    }
}

/// A helper function to recursively load the program and all of its imports into the process.
fn load_program(
    endpoint: &str,
    process: &mut Process<CurrentNetwork>,
    program_id: &ProgramID<CurrentNetwork>,
) -> Result<()> {
    // Fetch the program.
    let program = Developer::fetch_program(program_id, endpoint)?;

    // Return early if the program is already loaded.
    if process.contains_program(program.id()) {
        return Ok(());
    }

    // Iterate through the program imports.
    for import_program_id in program.imports().keys() {
        // Add the imports to the process if does not exist yet.
        if !process.contains_program(import_program_id) {
            // Recursively load the program and its imports.
            load_program(endpoint, process, import_program_id)?;
        }
    }

    // Add the program to the process if it does not already exist.
    if !process.contains_program(program.id()) {
        process.add_program(&program)?;
    }

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::commands::{Command, CLI};

    #[test]
    fn clap_snarkos_execute() {
        let arg_vec = vec![
            "snarkos",
            "developer",
            "execute",
            "--private-key",
            "PRIVATE_KEY",
            "--query",
            "QUERY",
            "--priority-fee",
            "77",
            "--record",
            "RECORD",
            "hello.aleo",
            "hello",
            "1u32",
            "2u32",
        ];
        let cli = CLI::parse_from(arg_vec);

        if let Command::Developer(Developer::Execute(execute)) = cli.command {
            assert_eq!(execute.private_key, "PRIVATE_KEY");
            assert_eq!(execute.query, "QUERY");
            assert_eq!(execute.priority_fee, Some(77));
            assert_eq!(execute.record, Some("RECORD".into()));
            assert_eq!(execute.program_id, "hello.aleo".try_into().unwrap());
            assert_eq!(execute.function, "hello".try_into().unwrap());
            assert_eq!(execute.inputs, vec!["1u32".try_into().unwrap(), "2u32".try_into().unwrap()]);
        } else {
            panic!("Unexpected result of clap parsing!");
        }
    }
}