import json
import uuid

from fastapi import APIRouter, File, Form, Response, UploadFile

from app.api.deps import CurrentUser, SessionDep
from app.schemas.gedcom import ImportPreview, ImportReport
from app.services import gedcom, tree_service

router = APIRouter(prefix="/trees", tags=["gedcom"])


@router.post("/{tree_id}/gedcom/preview", response_model=ImportPreview)
async def preview_gedcom(
    tree_id: uuid.UUID,
    session: SessionDep,
    current: CurrentUser,
    file: UploadFile = File(...),
) -> ImportPreview:
    """Dry run: report counts and incoming people that look like duplicates of
    existing ones, so the user can choose how to resolve each before importing."""
    tree = await tree_service.get_tree(session, viewer_id=current.id, tree_id=tree_id)
    text = (await file.read()).decode("utf-8", errors="replace")
    report = await gedcom.preview_gedcom(session, actor=current, tree=tree, text=text)
    return ImportPreview(**report)


@router.post("/{tree_id}/gedcom/import", response_model=ImportReport)
async def import_gedcom(
    tree_id: uuid.UUID,
    session: SessionDep,
    current: CurrentUser,
    file: UploadFile = File(...),
    default_action: str = Form("new"),
    resolutions: str = Form("{}"),
) -> ImportReport:
    """Import a GEDCOM. ``default_action`` (new|skip|merge|overwrite) applies to
    incoming people that match an existing one; ``resolutions`` is a JSON object
    {xref: {action, target_id}} overriding it per record."""
    tree = await tree_service.get_tree(session, viewer_id=current.id, tree_id=tree_id)
    text = (await file.read()).decode("utf-8", errors="replace")
    try:
        parsed = json.loads(resolutions or "{}")
    except json.JSONDecodeError:
        parsed = {}
    report = await gedcom.import_gedcom(
        session,
        actor=current,
        tree=tree,
        text=text,
        default_action=default_action,
        resolutions=parsed,
    )
    return ImportReport(**report)


@router.get("/{tree_id}/gedcom/export")
async def export_gedcom(
    tree_id: uuid.UUID, session: SessionDep, current: CurrentUser
) -> Response:
    tree = await tree_service.get_tree(session, viewer_id=current.id, tree_id=tree_id)
    text = await gedcom.export_gedcom(session, viewer_id=current.id, tree=tree)
    safe = "".join(c for c in tree.name if c.isalnum() or c in " -_").strip() or "tree"
    return Response(
        content=text,
        media_type="text/plain",
        headers={"Content-Disposition": f'attachment; filename="{safe}.ged"'},
    )