import os
import boto3
from datetime import datetime
from zoneinfo import ZoneInfo
from botocore.exceptions import ClientError

# Cache keyed by actor_id ('' = global/no user)
_prompt_cache: dict[str, str] = {}


def build_system_prompt(user_context: str = '', actor_id: str = '') -> str:
    """Build system prompt from S3 workspace files + optional per-user context."""
    base = _get_base_prompt(actor_id)

    # Dynamic block — injected fresh every call, never cached
    chicago = ZoneInfo('America/Chicago')
    now = datetime.now(chicago)
    dt_str = now.strftime('%A %Y-%m-%d %H:%M:%S %Z')
    time_block = (
        f'## Current Time\n'
        f'The current date and time is: {dt_str}\n\n'
        f'When examining any other date or time value, calculate its distance from now '
        f'(in seconds, minutes, hours, or days as appropriate) before drawing conclusions '
        f'like "upcoming", "overdue", "recent", "just happened", or "a long time ago". '
        f'Do this arithmetic explicitly — do not estimate or assume.'
    )

    parts = [base, time_block]
    if user_context:
        parts.append(f'## User\n{user_context}')
    return '\n\n---\n\n'.join(parts)


def _get_base_prompt(actor_id: str = '') -> str:
    if actor_id in _prompt_cache:
        return _prompt_cache[actor_id]

    bucket = os.environ.get('WORKSPACE_BUCKET_NAME', '') or 'agent-claw-workspace-495395224548'
    print(f'[prompt_builder] Loading from bucket: {bucket!r} actor_id={actor_id!r}')

    if not bucket:
        print('[prompt_builder] WARNING: WORKSPACE_BUCKET_NAME not set!')
        _prompt_cache[actor_id] = 'You are a helpful personal assistant.'
        return _prompt_cache[actor_id]

    s3 = boto3.client('s3')
    parts = []

    for fname in ['SOUL.md', 'STATUS.md']:
        try:
            obj = s3.get_object(Bucket=bucket, Key=fname)
            content = obj['Body'].read().decode('utf-8')
            if fname == 'STATUS.md':
                parts.append(f'## Status — In Progress\n{content}')
            else:
                parts.append(content)
            print(f'[prompt_builder] Loaded {fname} ({len(content)} bytes)')
        except Exception as e:
            print(f'[prompt_builder] Failed to load {fname}: {e}')

    parts.append(
        '## Memory\n'
        'Your memory works through two layers:\n\n'
        '**Conversation history (short-term):** AgentCore automatically loads your full '
        'conversation history with this user at the start of each session. You have complete '
        'context of everything discussed previously — no need to ask users to repeat themselves.\n\n'
        '**Long-term facts (LTM):** Important facts extracted from past conversations are '
        'retrieved and injected as context automatically. These are things like preferences, '
        'setup details, names, and recurring topics the user has shared.\n\n'
        'Guidelines:\n'
        '- Never ask "what did we discuss last time?" — you already have the history.\n'
        '- When a user shares something important (job interview, preference, key decision, '
        'setup change), acknowledge it and trust it will be captured — do not ask if they '
        'want you to remember it.\n'
        '- If you notice a fact that seems important but may not be in LTM yet (e.g. a '
        'deadline, a preference, a name), you may say "I\'ll keep that in mind" — but do '
        'not ask permission or make a production of it.\n'
        '- **In-progress tracking (STATUS.md):** When you start async work (CodeBuild job, '
        'reminder, deployment, anything you need to check back on), update STATUS.md using '
        "write_workspace_file('STATUS.md', content). Clear entries when complete. Check "
        "STATUS.md at the start of sessions where Daniel asks 'what's happening' or 'any updates'."
    )
    parts.append('## Runtime\nRuntime: agent-claw | host=AgentCore | model=bedrock-claude-sonnet | channel=telegram | timezone=America/Chicago')

    result = '\n\n---\n\n'.join(parts)
    _prompt_cache[actor_id] = result
    print(f'[prompt_builder] Prompt built for actor_id={actor_id!r}: {len(result)} chars')
    return result


def invalidate_prompt(actor_id: str = '') -> None:
    """Invalidate cached prompt for a specific actor_id, or all if not specified."""
    if actor_id:
        _prompt_cache.pop(actor_id, None)
    else:
        _prompt_cache.clear()