antegen-thread-program 5.0.8

use crate::{errors::AntegenThreadError, *};
use anchor_lang::{prelude::*, AnchorDeserialize, AnchorSerialize};
use std::{collections::hash_map::DefaultHasher, hash::Hasher};

// Re-export types from Fiber Program
pub use antegen_fiber_program::state::{
    compile_instruction, decompile_instruction, CompiledInstructionData, CompiledInstructionV0,
    SerializableAccountMeta, SerializableInstruction,
};
pub use antegen_fiber_program::{PAYER_PUBKEY, SEED_THREAD_FIBER};

/// Current version of the Thread structure.
pub const CURRENT_THREAD_VERSION: u8 = 1;

/// The triggering conditions of a thread.
#[derive(AnchorDeserialize, AnchorSerialize, Clone, InitSpace, PartialEq, Debug)]
pub enum Trigger {
    /// Allows a thread to be kicked off whenever the data of an account changes.
    Account {
        /// The address of the account to monitor.
        address: Pubkey,
        /// The byte offset of the account data to monitor.
        offset: u64,
        /// The size of the byte slice to monitor (must be less than 1kb)
        size: u64,
    },

    /// Allows a thread to be kicked off as soon as it's created.
    Immediate {
        /// Optional jitter in seconds to prevent thundering herd (0 = no jitter)
        jitter: u64,
    },

    /// Allows a thread to be kicked off according to a unix timestamp.
    Timestamp {
        unix_ts: i64,
        /// Optional jitter in seconds to spread execution across a window (0 = no jitter)
        jitter: u64,
    },

    /// Allows a thread to be kicked off at regular intervals.
    Interval {
        /// Interval in seconds between executions
        seconds: i64,
        /// Boolean value indicating whether triggering moments may be skipped
        skippable: bool,
        /// Optional jitter in seconds to prevent thundering herd (0 = no jitter)
        jitter: u64,
    },

    /// Allows a thread to be kicked off according to a one-time or recurring schedule.
    Cron {
        /// The schedule in cron syntax. Value must be parsable by the `antegen_cron` package.
        #[max_len(255)]
        schedule: String,

        /// Boolean value indicating whether triggering moments may be skipped if they are missed (e.g. due to network downtime).
        /// If false, any "missed" triggering moments will simply be executed as soon as the network comes back online.
        skippable: bool,

        /// Optional jitter in seconds to spread execution across a window (0 = no jitter)
        jitter: u64,
    },

    /// Allows a thread to be kicked off according to a slot.
    Slot { slot: u64 },

    /// Allows a thread to be kicked off according to an epoch number.
    Epoch { epoch: u64 },
}

/// Tracks the execution schedule - when the thread last ran and when it should run next
/// (was: TriggerContext)
#[derive(AnchorDeserialize, AnchorSerialize, Clone, InitSpace, Debug, PartialEq)]
pub enum Schedule {
    /// For Account triggers - tracks data hash for change detection
    OnChange { prev: u64 },

    /// For time-based triggers (Immediate, Timestamp, Interval, Cron)
    Timed { prev: i64, next: i64 },

    /// For block-based triggers (Slot, Epoch)
    Block { prev: u64, next: u64 },
}

/// Signal from a fiber about what should happen after execution.
/// Emitted via set_return_data(), received by thread program via get_return_data().
#[derive(AnchorDeserialize, AnchorSerialize, Clone, Default, InitSpace, Debug, PartialEq)]
pub enum Signal {
    #[default]
    None, // No signal - normal execution flow
    Chain,  // Chain to next fiber (same tx)
    Close,  // Chain to delete thread (same tx)
    Repeat, // Repeat this fiber on next trigger (skip cursor advancement)
    Next {
        index: u8, // Set specific fiber to execute on next trigger
    },
    Update {
        paused: Option<bool>,
        trigger: Option<Trigger>,
        index: Option<u8>,
    },
}

/// Tracks the current state of a transaction thread on Solana.
#[account]
#[derive(Debug, InitSpace)]
pub struct Thread {
    // Identity
    pub version: u8,
    pub bump: u8,
    pub authority: Pubkey,
    #[max_len(32)]
    pub id: Vec<u8>,
    #[max_len(64)]
    pub name: String,
    pub created_at: i64,

    // Scheduling
    pub trigger: Trigger,
    pub schedule: Schedule,

    // Fibers (all managed by Fiber Program as external FiberState accounts)
    #[max_len(50)]
    pub fiber_ids: Vec<u8>,
    pub fiber_cursor: u8,
    pub fiber_next_id: u8,
    pub fiber_signal: Signal,

    // Lifecycle
    pub paused: bool,

    // Execution tracking
    pub exec_count: u64,
    pub last_executor: Pubkey,

    // Nonce (for durable transactions)
    pub nonce_account: Pubkey,
    #[max_len(44)]
    pub last_nonce: String,

    // Pre-compiled thread_delete instruction for self-closing
    #[max_len(256)]
    pub close_fiber: Vec<u8>,
}

impl Thread {
    /// Derive the pubkey of a thread account.
    pub fn pubkey(authority: Pubkey, id: impl AsRef<[u8]>) -> Pubkey {
        let id_bytes = id.as_ref();
        assert!(id_bytes.len() <= 32, "Thread ID must not exceed 32 bytes");

        Pubkey::find_program_address(&[SEED_THREAD, authority.as_ref(), id_bytes], &crate::ID).0
    }

    /// Check if this thread has a nonce account.
    pub fn has_nonce_account(&self) -> bool {
        self.nonce_account != anchor_lang::solana_program::system_program::ID
            && self.nonce_account != crate::ID
    }

    /// Advance fiber_cursor to the next fiber in the sequence.
    pub fn advance_to_next_fiber(&mut self) {
        if self.fiber_ids.is_empty() {
            self.fiber_cursor = 0;
            return;
        }

        // Find current index position in fiber_ids vec
        if let Some(current_pos) = self.fiber_ids.iter().position(|&x| x == self.fiber_cursor) {
            // Move to next fiber, or wrap to beginning
            let next_pos = (current_pos + 1) % self.fiber_ids.len();
            self.fiber_cursor = self.fiber_ids[next_pos];
        } else {
            // Current fiber_cursor not found, reset to first fiber
            self.fiber_cursor = self.fiber_ids.first().copied().unwrap_or(0);
        }
    }

    /// Get the next fiber index in sequence (without mutating).
    /// Used to validate Chain signals target the correct consecutive fiber.
    pub fn next_fiber_index(&self) -> u8 {
        if self.fiber_ids.is_empty() {
            return 0;
        }
        if let Some(current_pos) = self.fiber_ids.iter().position(|&x| x == self.fiber_cursor) {
            let next_pos = (current_pos + 1) % self.fiber_ids.len();
            self.fiber_ids[next_pos]
        } else {
            self.fiber_ids.first().copied().unwrap_or(0)
        }
    }

    /// Get the fiber PDA for the current fiber_cursor
    pub fn fiber(&self, thread_pubkey: &Pubkey) -> Pubkey {
        self.fiber_at_index(thread_pubkey, self.fiber_cursor)
    }

    /// Get the fiber PDA for a specific fiber_index
    pub fn fiber_at_index(&self, thread_pubkey: &Pubkey, fiber_index: u8) -> Pubkey {
        Pubkey::find_program_address(
            &[SEED_THREAD_FIBER, thread_pubkey.as_ref(), &[fiber_index]],
            &antegen_fiber_program::ID,
        )
        .0
    }

    /// Get the next fiber PDA (for the next fiber_cursor in the sequence)
    pub fn next_fiber(&self, thread_pubkey: &Pubkey) -> Pubkey {
        // Calculate next index based on fiber_ids sequence
        let next_index = if self.fiber_ids.is_empty() {
            0
        } else if let Some(current_pos) =
            self.fiber_ids.iter().position(|&x| x == self.fiber_cursor)
        {
            let next_pos = (current_pos + 1) % self.fiber_ids.len();
            self.fiber_ids[next_pos]
        } else {
            self.fiber_ids.first().copied().unwrap_or(0)
        };

        self.fiber_at_index(thread_pubkey, next_index)
    }

    /// Check if thread is ready to execute based on schedule
    pub fn is_ready(&self, current_slot: u64, current_timestamp: i64) -> bool {
        match &self.schedule {
            Schedule::Timed { next, .. } => current_timestamp >= *next,
            Schedule::Block { next, .. } => {
                match &self.trigger {
                    Trigger::Slot { .. } => current_slot >= *next,
                    Trigger::Epoch { .. } => {
                        // For epoch triggers, we'd need epoch info
                        // This is a simplified check
                        false
                    }
                    _ => false,
                }
            }
            Schedule::OnChange { .. } => {
                // Account triggers are handled by the observer
                false
            }
        }
    }

    /// Validate that the thread is ready for execution
    pub fn validate_for_execution(&self) -> Result<()> {
        // Check that thread has fibers
        require!(
            !self.fiber_ids.is_empty(),
            crate::errors::AntegenThreadError::ThreadHasNoFibersToExecute
        );

        // Check that fiber_cursor is valid (must exist in fiber_ids)
        require!(
            self.fiber_ids.contains(&self.fiber_cursor),
            crate::errors::AntegenThreadError::InvalidExecIndex
        );

        Ok(())
    }
}

impl TryFrom<Vec<u8>> for Thread {
    type Error = Error;

    fn try_from(data: Vec<u8>) -> std::result::Result<Self, Self::Error> {
        Thread::try_deserialize(&mut data.as_slice())
    }
}

/// Trait for processing trigger validation and schedule updates
pub trait TriggerProcessor {
    fn validate_trigger(
        &self,
        clock: &Clock,
        remaining_accounts: &[AccountInfo],
        thread_pubkey: &Pubkey,
    ) -> Result<i64>; // Returns time_since_ready (elapsed time since trigger was ready)

    fn update_schedule(
        &mut self,
        clock: &Clock,
        remaining_accounts: &[AccountInfo],
        thread_pubkey: &Pubkey,
    ) -> Result<()>; // Updates schedule for next execution

    fn get_last_started_at(&self) -> i64;
}

/// Trait for getting thread seeds for signing
pub trait ThreadSeeds {
    fn get_seed_bytes(&self) -> Vec<Vec<u8>>;

    /// Use seeds with a callback to avoid lifetime issues
    fn sign<F, R>(&self, f: F) -> R
    where
        F: FnOnce(&[&[u8]]) -> R,
    {
        let seed_bytes = self.get_seed_bytes();
        let seeds: Vec<&[u8]> = seed_bytes.iter().map(|s| s.as_slice()).collect();
        f(&seeds)
    }
}

/// Trait for handling nonce account operations
pub trait NonceProcessor {
    fn advance_nonce_if_required<'info>(
        &self,
        thread_account_info: &AccountInfo<'info>,
        nonce_account: &Option<UncheckedAccount<'info>>,
        recent_blockhashes: &Option<UncheckedAccount<'info>>,
    ) -> Result<()>;
}

/// Trait for distributing payments
pub trait PaymentDistributor {
    fn distribute_payments<'info>(
        &self,
        thread_account: &AccountInfo<'info>,
        executor: &AccountInfo<'info>,
        admin: &AccountInfo<'info>,
        payments: &crate::state::PaymentDetails,
    ) -> Result<()>;
}

impl TriggerProcessor for Thread {
    fn validate_trigger(
        &self,
        clock: &Clock,
        remaining_accounts: &[AccountInfo],
        thread_pubkey: &Pubkey,
    ) -> Result<i64> {
        let last_started_at = self.get_last_started_at();

        // Determine trigger ready time and validate
        let trigger_ready_time = match &self.trigger {
            Trigger::Immediate { jitter } => {
                let jitter_offset =
                    crate::utils::calculate_jitter_offset(last_started_at, thread_pubkey, *jitter);
                clock.unix_timestamp.saturating_add(jitter_offset)
            }

            Trigger::Timestamp { unix_ts, jitter } => {
                let jitter_offset =
                    crate::utils::calculate_jitter_offset(last_started_at, thread_pubkey, *jitter);
                let trigger_time = unix_ts.saturating_add(jitter_offset);

                require!(
                    clock.unix_timestamp >= trigger_time,
                    AntegenThreadError::TriggerConditionFailed
                );
                trigger_time
            }

            Trigger::Slot { slot } => {
                require!(
                    clock.slot >= *slot,
                    AntegenThreadError::TriggerConditionFailed
                );
                // Approximate when slot was reached (assuming 400ms per slot)
                clock.unix_timestamp - ((clock.slot - slot) as i64 * 400 / 1000)
            }

            Trigger::Epoch { epoch } => {
                require!(
                    clock.epoch >= *epoch,
                    AntegenThreadError::TriggerConditionFailed
                );
                clock.unix_timestamp
            }

            Trigger::Interval {
                seconds: _,
                skippable: _,
                jitter: _,
            } => {
                // schedule.next already has jitter baked in from previous execution
                let trigger_time = match self.schedule {
                    Schedule::Timed { next, .. } => next,
                    _ => return Err(AntegenThreadError::TriggerConditionFailed.into()),
                };

                require!(
                    clock.unix_timestamp >= trigger_time,
                    AntegenThreadError::TriggerConditionFailed
                );
                trigger_time
            }

            Trigger::Cron {
                schedule: _,
                skippable: _,
                jitter: _,
            } => {
                // schedule.next already has jitter baked in from previous execution
                let trigger_time = match self.schedule {
                    Schedule::Timed { next, .. } => next,
                    _ => return Err(AntegenThreadError::TriggerConditionFailed.into()),
                };

                require!(
                    clock.unix_timestamp >= trigger_time,
                    AntegenThreadError::TriggerConditionFailed
                );
                trigger_time
            }

            Trigger::Account {
                address,
                offset,
                size,
            } => {
                // Verify proof account is provided
                let account_info = remaining_accounts
                    .first()
                    .ok_or(AntegenThreadError::TriggerConditionFailed)?;

                // Verify it's the correct account
                require!(
                    address.eq(account_info.key),
                    AntegenThreadError::TriggerConditionFailed
                );

                // Compute data hash
                let mut hasher = DefaultHasher::new();
                let data = &account_info.try_borrow_data()?;
                let offset = *offset as usize;
                let range_end = offset.checked_add(*size as usize).unwrap() as usize;

                use std::hash::Hash;
                if data.len() > range_end {
                    data[offset..range_end].hash(&mut hasher);
                } else {
                    data[offset..].hash(&mut hasher);
                }
                let data_hash = hasher.finish();

                // Verify hash changed
                if let Schedule::OnChange { prev: prior_hash } = &self.schedule {
                    require!(
                        data_hash.ne(prior_hash),
                        AntegenThreadError::TriggerConditionFailed
                    );
                }

                clock.unix_timestamp
            }
        };

        // Return elapsed time since trigger was ready
        Ok(clock.unix_timestamp.saturating_sub(trigger_ready_time))
    }

    fn update_schedule(
        &mut self,
        clock: &Clock,
        remaining_accounts: &[AccountInfo],
        thread_pubkey: &Pubkey,
    ) -> Result<()> {
        let current_timestamp = clock.unix_timestamp;

        self.schedule = match &self.trigger {
            Trigger::Account { offset, size, .. } => {
                // Compute data hash for Account trigger
                let account_info = remaining_accounts
                    .first()
                    .ok_or(AntegenThreadError::TriggerConditionFailed)?;

                let mut hasher = DefaultHasher::new();
                let data = &account_info.try_borrow_data()?;
                let offset = *offset as usize;
                let range_end = offset.checked_add(*size as usize).unwrap() as usize;

                use std::hash::Hash;
                if data.len() > range_end {
                    data[offset..range_end].hash(&mut hasher);
                } else {
                    data[offset..].hash(&mut hasher);
                }
                let data_hash = hasher.finish();

                Schedule::OnChange { prev: data_hash }
            }
            Trigger::Cron {
                schedule, jitter, ..
            } => {
                // Calculate next cron time WITH jitter baked in
                // Use current_timestamp since this is called right after execution
                let next_cron = crate::utils::next_timestamp(current_timestamp, schedule.clone())
                    .ok_or(AntegenThreadError::TriggerConditionFailed)?;
                let next_jitter = crate::utils::calculate_jitter_offset(
                    current_timestamp,
                    thread_pubkey,
                    *jitter,
                );
                let next_trigger_time = next_cron.saturating_add(next_jitter);

                Schedule::Timed {
                    prev: current_timestamp,
                    next: next_trigger_time,
                }
            }
            Trigger::Immediate { .. } => Schedule::Timed {
                prev: current_timestamp,
                next: 0, // Use 0 instead of i64::MAX to avoid JSON serialization issues
            },
            Trigger::Slot { slot } => Schedule::Block {
                prev: clock.slot,
                next: *slot,
            },
            Trigger::Epoch { epoch } => Schedule::Block {
                prev: clock.epoch,
                next: *epoch,
            },
            Trigger::Interval {
                seconds, jitter, ..
            } => {
                // Calculate next trigger time WITH jitter baked in
                // Use current_timestamp since this is called right after execution
                let next_base = current_timestamp.saturating_add(*seconds);
                let next_jitter = crate::utils::calculate_jitter_offset(
                    current_timestamp,
                    thread_pubkey,
                    *jitter,
                );
                let next_trigger_time = next_base.saturating_add(next_jitter);

                Schedule::Timed {
                    prev: current_timestamp,
                    next: next_trigger_time,
                }
            }
            Trigger::Timestamp { unix_ts, .. } => Schedule::Timed {
                prev: current_timestamp,
                next: *unix_ts,
            },
        };

        Ok(())
    }

    fn get_last_started_at(&self) -> i64 {
        match &self.schedule {
            Schedule::Timed { prev, .. } => *prev,
            Schedule::Block { prev, .. } => *prev as i64,
            Schedule::OnChange { .. } => self.created_at,
        }
    }
}

impl ThreadSeeds for Thread {
    fn get_seed_bytes(&self) -> Vec<Vec<u8>> {
        vec![
            SEED_THREAD.to_vec(),
            self.authority.to_bytes().to_vec(),
            self.id.clone(),
            vec![self.bump],
        ]
    }
}

impl PaymentDistributor for Thread {
    fn distribute_payments<'info>(
        &self,
        thread_account: &AccountInfo<'info>,
        executor: &AccountInfo<'info>,
        admin: &AccountInfo<'info>,
        payments: &crate::state::PaymentDetails,
    ) -> Result<()> {
        use crate::utils::transfer_lamports;

        // Combined payment to executor (reimbursement + commission)
        let total_executor_payment =
            payments.fee_payer_reimbursement + payments.executor_commission;

        // Log all payments in one line for conciseness
        if total_executor_payment > 0 || payments.core_team_fee > 0 {
            msg!(
                "Payments: executor {} (reimburse {}, commission {}), team {}",
                total_executor_payment,
                payments.fee_payer_reimbursement,
                payments.executor_commission,
                payments.core_team_fee
            );
        }

        if total_executor_payment > 0 {
            transfer_lamports(thread_account, executor, total_executor_payment)?;
        }

        // Transfer core team fee to admin
        if payments.core_team_fee > 0 {
            transfer_lamports(thread_account, admin, payments.core_team_fee)?;
        }

        Ok(())
    }
}

impl NonceProcessor for Thread {
    fn advance_nonce_if_required<'info>(
        &self,
        thread_account_info: &AccountInfo<'info>,
        nonce_account: &Option<UncheckedAccount<'info>>,
        recent_blockhashes: &Option<UncheckedAccount<'info>>,
    ) -> Result<()> {
        use anchor_lang::solana_program::{
            program::invoke_signed, system_instruction::advance_nonce_account,
        };

        if !self.has_nonce_account() {
            return Ok(());
        }

        match (nonce_account, recent_blockhashes) {
            (Some(nonce_acc), Some(recent_bh)) => {
                // Get thread key from account info
                let thread_key = *thread_account_info.key;

                // Use seeds with callback to handle invoke_signed
                self.sign(|seeds| {
                    invoke_signed(
                        &advance_nonce_account(&nonce_acc.key(), &thread_key),
                        &[
                            nonce_acc.to_account_info(),
                            recent_bh.to_account_info(),
                            thread_account_info.clone(),
                        ],
                        &[seeds],
                    )
                })?;
                Ok(())
            }
            _ => Err(AntegenThreadError::NonceRequired.into()),
        }
    }
}