use prometeu_bytecode::TrapInfo;
use prometeu_vm::VmInitError;
use std::fmt;

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum CrashReport {
    VmTrap { trap: TrapInfo },
    VmPanic { message: String, pc: Option<u32> },
    VmInit { error: VmInitError },
}

impl CrashReport {
    pub fn kind(&self) -> &'static str {
        match self {
            Self::VmTrap { .. } => "vm_trap",
            Self::VmPanic { .. } => "vm_panic",
            Self::VmInit { .. } => "vm_init",
        }
    }

    pub fn pc(&self) -> Option<u32> {
        match self {
            Self::VmTrap { trap } => Some(trap.pc),
            Self::VmPanic { pc, .. } => *pc,
            Self::VmInit { .. } => None,
        }
    }

    pub fn summary(&self) -> String {
        match self {
            Self::VmTrap { trap } => format!(
                "PVM Trap 0x{:08X} at PC 0x{:X} (opcode 0x{:04X}): {}",
                trap.code, trap.pc, trap.opcode, trap.message
            ),
            Self::VmPanic { message, pc: Some(pc) } => {
                format!("PVM Panic at PC 0x{:X}: {}", pc, message)
            }
            Self::VmPanic { message, pc: None } => format!("PVM Panic: {}", message),
            Self::VmInit { error } => format!("PVM Init Error: {:?}", error),
        }
    }

    pub fn log_tag(&self) -> u16 {
        match self {
            Self::VmTrap { trap } => trap.code as u16,
            Self::VmPanic { .. } | Self::VmInit { .. } => 0,
        }
    }
}

impl fmt::Display for CrashReport {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(&self.summary())
    }
}