use serde::{Deserialize, Serialize};
use super::ids::{ConstId, FieldId, FunctionId, TypeId, ValueId};

/// Instructions within a basic block.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum Instr {
    /// Placeholder for constant loading.
    PushConst(ConstId),
    /// Push a bounded value (0..0xFFFF).
    PushBounded(u32),
    /// Placeholder for function calls.
    Call(FunctionId, u32),
    /// External calls (imports). (dep_alias, module_path, symbol_name, arg_count)
    ImportCall(String, String, String, u32),
    /// Host calls (syscalls). (id, return_slots)
    HostCall(u32, u32),
    /// Variable access.
    GetLocal(u32),
    SetLocal(u32),
    /// Stack operations.
    Pop,
    Dup,
    /// Arithmetic.
    Add,
    Sub,
    Mul,
    Div,
    Neg,
    /// Logical/Comparison.
    Eq,
    Neq,
    Lt,
    Lte,
    Gt,
    Gte,
    And,
    Or,
    Not,
    /// HIP operations.
    Alloc { ty: TypeId, slots: u32 },
    BeginPeek { gate: ValueId },
    BeginBorrow { gate: ValueId },
    BeginMutate { gate: ValueId },
    EndPeek,
    EndBorrow,
    EndMutate,
    /// Reads from heap at gate + field. Pops gate, pushes value.
    GateLoadField { gate: ValueId, field: FieldId },
    /// Writes to heap at gate + field. Pops gate and value.
    GateStoreField { gate: ValueId, field: FieldId, value: ValueId },
    /// Reads from heap at gate + index.
    GateLoadIndex { gate: ValueId, index: ValueId },
    /// Writes to heap at gate + index.
    GateStoreIndex { gate: ValueId, index: ValueId, value: ValueId },
    Free,
}