"""System settings routes — get, upsert, backup config (admin only)."""

from __future__ import annotations

import uuid

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field
from sqlalchemy import select as sa_select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.db import get_db
from app.core.jobs import enqueue_job
from app.deps import require_permission
from app.models.audit import AuditLog
from app.schemas.system_settings import SystemSettingsResponse, SystemSettingsUpsert
from app.services import system_settings_service

router = APIRouter(prefix="/api/v1/system-settings", tags=["system-settings"])


class BackupConfigRequest(BaseModel):
    """Update backup configuration (all fields optional)."""

    backup_enabled: bool | None = None
    backup_interval: str | None = Field(None, max_length=20)
    backup_retention_days: int | None = Field(None, ge=1, le=365)
    backup_destination: str | None = Field(None, max_length=20)


class DsarRequest(BaseModel):
    """Submit a Data Subject Access Request."""

    type: str = Field("access", pattern="^(access|deletion|rectification)$")


@router.get("", response_model=SystemSettingsResponse)
async def get_system_settings(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:read")),
):
    """Get system settings for the current tenant.

    Sensitive fields (tax_number, iban, bic) are masked for non-admin users.
    """
    tenant_id = uuid.UUID(current_user["tenant_id"])
    result = await system_settings_service.get_system_settings(db, tenant_id)
    if result is None:
        return SystemSettingsResponse()

    # Mask sensitive fields for non-admin users
    if not current_user.get("is_system_admin"):
        if hasattr(result, "tax_number") and result.tax_number:
            result.tax_number = "********"
        if hasattr(result, "iban") and result.iban:
            result.iban = "********"
        if hasattr(result, "bic") and result.bic:
            result.bic = "********"

    return result


@router.put("", response_model=SystemSettingsResponse)
async def upsert_system_settings(
    body: SystemSettingsUpsert,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:write")),
):
    """Upsert system settings. Requires admin permission."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])

    data = body.model_dump()
    return await system_settings_service.upsert_system_settings(db, tenant_id, user_id, data)


# ── Backup configuration endpoints ───────────────────────────────────────────


@router.get("/backup-config")
async def get_backup_config(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:read")),
):
    """Get backup configuration for the current tenant."""
    tenant_id = uuid.UUID(current_user["tenant_id"])
    result = await system_settings_service.get_system_settings(db, tenant_id)
    if result is None:
        return {
            "backup_enabled": False,
            "backup_interval": "24h",
            "backup_retention_days": 7,
            "backup_destination": "local",
        }
    return {
        "backup_enabled": result.get("backup_enabled", False),
        "backup_interval": result.get("backup_interval", "24h"),
        "backup_retention_days": result.get("backup_retention_days", 7),
        "backup_destination": result.get("backup_destination", "local"),
    }


@router.put("/backup-config")
async def update_backup_config(
    body: BackupConfigRequest,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:write")),
):
    """Update backup configuration. Admin only.

    Accepts: backup_enabled (bool), backup_interval (str),
    backup_retention_days (int), backup_destination (str).
    """
    tenant_id = uuid.UUID(current_user["tenant_id"])
    user_id = uuid.UUID(current_user["user_id"])

    # Get existing settings
    existing = await system_settings_service.get_system_settings(db, tenant_id)
    if existing is None:
        raise HTTPException(404, detail={"detail": "System settings not found. Please configure company settings first.", "code": "settings_not_found"})

    # Merge backup fields into existing data
    data = dict(existing)
    updates = body.model_dump(exclude_unset=True)
    for key in (
        "backup_enabled",
        "backup_interval",
        "backup_retention_days",
        "backup_destination",
    ):
        if key in updates:
            data[key] = updates[key]

    return await system_settings_service.upsert_system_settings(db, tenant_id, user_id, data)


@router.post("/backup-now")
async def trigger_backup_now(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:write")),
):
    """Trigger an immediate backup via ARQ job. Admin only."""
    job_id = await enqueue_job("run_backup")
    if job_id is None:
        raise HTTPException(503, detail={"detail": "Failed to enqueue backup job. Worker may not be running.", "code": "enqueue_failed"})
    return {"message": "Backup job enqueued", "job_id": job_id}


@router.get("/backup-history")
async def get_backup_history(
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("settings:read")),
):
    """Get last 10 backup results from audit log."""
    tenant_id = uuid.UUID(current_user["tenant_id"])

    stmt = (
        sa_select(AuditLog)
        .where(
            AuditLog.tenant_id == tenant_id,
            AuditLog.entity_type == "backup",
            AuditLog.action.in_(["backup_success", "backup_failed"]),
        )
        .order_by(AuditLog.timestamp.desc())
        .limit(10)
    )
    result = await db.execute(stmt)
    entries = result.scalars().all()

    history = []
    for entry in entries:
        changes = entry.changes or {}
        history.append({
            "id": str(entry.id),
            "timestamp": entry.timestamp.isoformat() if entry.timestamp else None,
            "action": entry.action,
            "success": changes.get("success", entry.action == "backup_success"),
            "destination": changes.get("destination", "local"),
            "error": changes.get("error", ""),
        })

    return {"history": history}


# ── I.5 DSGVO Export ──

@router.get("/dsgvo-export/{user_id}")
async def dsgvo_export(
    user_id: str,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("system:admin")),
):
    """Export all personal data for a user (DSGVO/GDPR data subject access request).

    Audit P1/P2 (DSGVO duplicate): this route previously held a second,
    contact-aware export implementation parallel to the newer DSAR job
    pipeline. It now delegates to the single authoritative collector
    ``app.core.jobs._dsar_collect_user_data`` — core-owned categories are
    collected there, plugin-owned categories (contacts, mail, tasks,
    calendar, communication, ...) are contributed by the plugin contracts.
    No core->contacts coupling here anymore.
    """
    import io
    import json

    from fastapi.responses import StreamingResponse

    from app.core.jobs import _dsar_collect_user_data

    tenant_id = uuid.UUID(current_user["tenant_id"])
    try:
        uid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid user_id", "code": "invalid_id"}) from None

    export_data = await _dsar_collect_user_data(db, str(tenant_id), str(uid))

    # Log the DSGVO export
    from app.core.audit import log_audit
    await log_audit(db, tenant_id, current_user.get("user_id", ""), "dsgvo_export", "user", uid, {"target_user": str(uid)})
    await db.commit()

    content = json.dumps(export_data, indent=2, default=str)
    return StreamingResponse(
        io.BytesIO(content.encode("utf-8")),
        media_type="application/json",
        headers={"Content-Disposition": f"attachment; filename=dsgvo_export_{user_id}.json"},
    )


@router.post("/dsar/{user_id}")
async def dsar_request(
    user_id: str,
    body: DsarRequest,
    db: AsyncSession = Depends(get_db),
    current_user: dict = Depends(require_permission("system:admin")),
):
    """Submit a Data Subject Access Request (DSAR) for processing.

    Queues a DSAR job that collects and exports all user data.
    Types: access, deletion, rectification.
    """
    from app.core.jobs import enqueue_job
    tenant_id = uuid.UUID(current_user["tenant_id"])
    request_type = body.type
    try:
        uid = uuid.UUID(user_id)
    except ValueError:
        raise HTTPException(400, detail={"detail": "Invalid user_id", "code": "invalid_id"}) from None

    job_id = await enqueue_job("process_dsar", user_id=str(uid), tenant_id=str(tenant_id), request_type=request_type)
    return {"job_id": job_id, "status": "queued", "type": request_type, "user_id": str(uid)}