"""Timestamp providers."""

import hashlib
from datetime import datetime
from typing import Optional

from .base import TimestampProvider, ProviderHealth, ProviderStatus
from ..config.providers import TimestampConfig


class RFC3161TimestampProvider(TimestampProvider[TimestampConfig]):
    """RFC 3161 Time Stamp Authority provider.
    
    TODO: Implement actual RFC 3161 integration.
    For now, this is a placeholder that matches the interface.
    """
    
    async def initialize(self) -> None:
        if not self.config.tsa_url:
            raise ValueError("TSA URL required for RFC 3161 provider")
        self._initialized = True
    
    async def shutdown(self) -> None:
        self._initialized = False
    
    async def health_check(self) -> ProviderHealth:
        # TODO: Actually ping the TSA
        return ProviderHealth(
            status=ProviderStatus.HEALTHY,
            message=f"RFC 3161 TSA at {self.config.tsa_url}"
        )
    
    async def timestamp(self, data: bytes) -> bytes:
        # TODO: Implement actual RFC 3161 timestamp request
        raise NotImplementedError("RFC 3161 implementation pending")
    
    async def verify(self, data: bytes, token: bytes) -> tuple[bool, Optional[datetime]]:
        # TODO: Implement actual RFC 3161 verification
        raise NotImplementedError("RFC 3161 implementation pending")


class MockTimestampProvider(TimestampProvider[TimestampConfig]):
    """Mock timestamp provider for testing."""
    
    def __init__(self, config: TimestampConfig):
        super().__init__(config)
        self._timestamps: dict[bytes, datetime] = {}
    
    async def initialize(self) -> None:
        self._initialized = True
    
    async def shutdown(self) -> None:
        self._timestamps.clear()
        self._initialized = False
    
    async def health_check(self) -> ProviderHealth:
        return ProviderHealth(
            status=ProviderStatus.HEALTHY,
            message="Mock timestamp provider"
        )
    
    async def timestamp(self, data: bytes) -> bytes:
        now = datetime.utcnow()
        data_hash = hashlib.sha256(data).hexdigest()[:16]
        token = f"MOCK_TSA|{now.isoformat()}|{data_hash}".encode()
        self._timestamps[token] = now
        return token
    
    async def verify(self, data: bytes, token: bytes) -> tuple[bool, Optional[datetime]]:
        try:
            decoded = token.decode()
            if not decoded.startswith("MOCK_TSA|"):
                return False, None
            
            parts = decoded.split("|")
            if len(parts) != 3:
                return False, None
            
            timestamp_str = parts[1]
            stored_hash = parts[2]
            
            actual_hash = hashlib.sha256(data).hexdigest()[:16]
            if actual_hash != stored_hash:
                return False, None
            
            return True, datetime.fromisoformat(timestamp_str)
        except Exception:
            return False, None
