from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, Query
from pydantic import BaseModel, ConfigDict, Field

from ..db.session import get_session
from ..services.audit_logger import log_event
from ..services.action_execution import approval_execution_supported, execute_approved_action
from ..services.approval_service import (
    ApprovalStateError,
    approval_fingerprint,
    create_approval,
    dismiss_expired_approvals,
    get_approval,
    list_approvals,
    mark_approval_executed,
    update_approval_status,
)

router = APIRouter(prefix='/api/approvals')


class ApprovalCreateRequest(BaseModel):
    model_config = ConfigDict(extra='forbid')
    action: str = Field(min_length=1, max_length=160)
    target: str = Field(min_length=1, max_length=240)
    source: str = Field(default='manual', pattern='^(manual|voice|automation|system)$')
    risk: str = Field(default='medium', pattern='^(low|medium|high|critical)$')
    reason: str | None = Field(default=None, max_length=1000)
    requester: str = Field(default='manual', max_length=120)
    plan: list[str] = Field(default_factory=list, max_length=30)


class ApprovalDecisionRequest(BaseModel):
    model_config = ConfigDict(extra='forbid')
    status: str = Field(min_length=1, max_length=32)


@router.get('')
def list_all(include_dismissed: bool = Query(default=False), session=Depends(get_session)):
    return [
        {
            **approval.model_dump(),
            'executionSupported': approval_execution_supported(approval.action),
            'executionReason': None if approval_execution_supported(approval.action) else 'Geen rollback-veilige executor geregistreerd.',
        }
        for approval in list_approvals(session, include_dismissed=include_dismissed)
    ]


@router.post('/cleanup')
def cleanup_expired(session=Depends(get_session)):
    dismissed = dismiss_expired_approvals(session)
    audit = log_event(
        session,
        source='manual',
        identity='operator',
        action_id='approval.cleanup',
        target='approval-queue',
        target_type='approval',
        risk='low',
        policy_decision='allowed',
        reason=f'{len(dismissed)} expired approval(s) archived; active approvals were retained.',
        result='success',
        execution_plan={'steps': ['expire overdue pending approvals', 'archive expired approvals', 'retain approval and audit records']},
        redacted_metadata={'dismissedCount': len(dismissed)},
    )
    return {
        'success': True,
        'message': f'{len(dismissed)} verlopen approval(s) opgeruimd.',
        'dismissedCount': len(dismissed),
        'auditId': audit.id,
    }


@router.post('')
def create(payload: ApprovalCreateRequest, session=Depends(get_session)):
    approval = create_approval(
        session,
        action=payload.action,
        target=payload.target,
        source=payload.source,
        risk=payload.risk,
        reason=payload.reason,
        requester=payload.requester,
        context={'plan': payload.plan},
    )
    return {'success': True, 'message': 'Approval created', 'id': approval.id}


@router.patch('/{approval_id}')
def update(approval_id: str, payload: ApprovalDecisionRequest, session=Depends(get_session)):
    status = payload.status
    try:
        updated = update_approval_status(session, approval_id, status)
    except ApprovalStateError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    if not updated:
        return {'success': False, 'message': 'Approval not found', 'id': approval_id}

    audit = log_event(
        session,
        source='manual',
        identity='operator',
        action_id=f'approval.{status}',
        target=updated.target,
        target_type='approval',
        risk=updated.risk,
        policy_decision='approval_required',
        reason=updated.reason or f'Approval {approval_id} marked {status}.',
        result='success',
        execution_plan={'steps': ['load approval', f'mark {status}', 'write audit']},
        redacted_metadata={'approvalId': updated.id, 'approvalStatus': updated.status, 'requestedAction': updated.action},
    )

    return {
        'success': True,
        'id': updated.id,
        'status': updated.status,
        'auditId': audit.id,
        'message': f'Approval {updated.status}',
    }


@router.post('/{approval_id}/execute')
def execute_approved(approval_id: str, session=Depends(get_session)):
    approval = get_approval(session, approval_id)
    if not approval:
        raise HTTPException(status_code=404, detail='Approval not found.')
    if approval.status != 'approved':
        raise HTTPException(status_code=409, detail='Only an approved request can be executed.')
    expected = approval_fingerprint(approval.action, approval.target, approval.source, approval.risk, approval.request_context_json)
    if not approval.action_fingerprint or approval.action_fingerprint != expected:
        raise HTTPException(status_code=409, detail='Approval action context changed after review.')

    result = execute_approved_action(session, approval)
    if not result.get('success'):
        return result

    mark_approval_executed(
        session,
        approval,
        job_id=str(result['jobId']),
        audit_event_id=str(result['auditId']),
    )
    return {
        **result,
        'approvalId': approval.id,
        'approvalStatus': 'executed',
    }