"""Photo policy and per-section report photo upload endpoints."""

from __future__ import annotations

import logging
import uuid
from pathlib import Path

from fastapi import APIRouter, Depends, File, HTTPException, Request, UploadFile
from fastapi.responses import FileResponse
from sqlalchemy import delete, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.rate_limit import check_read
from app.config import settings
from app.db.database import get_db
from app.db.models import Report, ReportSectionPhoto
from app.models.schemas import SectionPhotoAiSelectionRequest
from app.services.photo_policy import get_photo_policy_for_tenant_async, photo_policy_configuration_incomplete
from app.storage.photo_paths import report_photo_relpath, resolve_report_photo_path
from app.templates.registry import ALL_VALID_SECTION_CODES

logger = logging.getLogger(__name__)
router = APIRouter()


def _validate_section_code(code: str) -> str:
    c = (code or "").strip()
    if not c:
        raise HTTPException(status_code=422, detail="section_code is required")
    if c not in ALL_VALID_SECTION_CODES:
        raise HTTPException(status_code=422, detail=f"Unknown section_code '{c}'")
    return c


def _report_photo_dir(tenant_id: str, report_id: str, section_code: str) -> Path:
    return settings.upload_dir / tenant_id / "report_photos" / str(report_id) / str(section_code)


def _photo_item_dict(report_id: str, section_code: str, row: ReportSectionPhoto) -> dict:
    return {
        "photo_id": row.id,
        "original_filename": row.original_filename,
        "content_type": row.content_type,
        "created_at": row.created_at.isoformat() if row.created_at else "",
        "url": f"/reports/{report_id}/sections/{section_code}/photos/{row.id}",
        "selected_for_ai": bool(getattr(row, "selected_for_ai", False)),
    }


def _validate_content_type(ct: str | None) -> str:
    content_type = (ct or "").strip().lower()
    if content_type not in ("image/jpeg", "image/png", "image/webp"):
        raise HTTPException(status_code=415, detail="Only JPEG, PNG, or WEBP images are supported.")
    return content_type


@router.get(
    "/reports/{report_id}/photo-policy",
    summary="Per-section photo policy for this report (requires/optional/none)",
)
async def get_report_photo_policy(
    report_id: str,
    request: Request,
    db: AsyncSession = Depends(get_db),
    _: None = Depends(check_read),
) -> dict:
    tenant_id: str = request.state.tenant_id
    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    items, stats = await get_photo_policy_for_tenant_async(db, tenant_id, report.survey_level)
    return {
        "report_id": report_id,
        "survey_level": report.survey_level or 3,
        "indexed_upload_count": stats.files_total,
        "policy_configuration_required": photo_policy_configuration_incomplete(stats, items),
        "photo_limits": {
            "max_photos_per_section": int(settings.max_section_photos_per_section),
            "max_photos_for_ai": int(settings.max_section_photos_for_ai),
        },
        "sections": [
            {"code": x.code, "policy": x.policy.value, "reason": x.reason, "source": x.source}
            for x in items
        ],
    }


@router.post(
    "/reports/{report_id}/sections/{section_code}/photos",
    summary="Upload one or more photos for a report section",
)
async def upload_section_photos(
    report_id: str,
    section_code: str,
    request: Request,
    files: list[UploadFile] = File(...),
    db: AsyncSession = Depends(get_db),
) -> dict:
    tenant_id: str = request.state.tenant_id
    section_code = _validate_section_code(section_code)

    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    if not files:
        raise HTTPException(status_code=422, detail="No files uploaded")

    # Enforce per-section cap (existing + new)
    existing_cnt = await db.execute(
        select(func.count())
        .select_from(ReportSectionPhoto)
        .where(
            ReportSectionPhoto.tenant_id == tenant_id,
            ReportSectionPhoto.report_id == report_id,
            ReportSectionPhoto.section_code == section_code,
        )
    )
    existing = int(existing_cnt.scalar_one() or 0)
    max_per = int(settings.max_section_photos_per_section)
    if max_per >= 0 and existing + len(files) > max_per:
        raise HTTPException(
            status_code=422,
            detail=f"Too many photos for section {section_code}. Max is {max_per}.",
        )

    saved: list[dict] = []
    for uf in files:
        content_type = _validate_content_type(uf.content_type)
        raw = await uf.read()
        if len(raw) > int(settings.max_section_photo_bytes):
            raise HTTPException(status_code=413, detail="Photo exceeds max_section_photo_bytes limit.")

        ext = "jpg" if content_type == "image/jpeg" else "png" if content_type == "image/png" else "webp"
        pid = str(uuid.uuid4())
        rel_path = report_photo_relpath(tenant_id, str(report_id), section_code, pid, ext)
        dest_path = settings.upload_dir / rel_path
        dest_path.parent.mkdir(parents=True, exist_ok=True)
        dest_path.write_bytes(raw)

        row = ReportSectionPhoto(
            id=pid,
            tenant_id=tenant_id,
            report_id=str(report_id),
            section_code=section_code,
            file_path=rel_path,
            original_filename=uf.filename or "upload",
            content_type=content_type,
        )
        db.add(row)
        await db.flush()
        saved.append(_photo_item_dict(str(report_id), section_code, row))

    await db.commit()
    return {"report_id": report_id, "section_code": section_code, "saved": saved}


@router.get(
    "/reports/{report_id}/sections/{section_code}/photos",
    summary="List uploaded photos for a report section",
)
async def list_section_photos(
    report_id: str,
    section_code: str,
    request: Request,
    db: AsyncSession = Depends(get_db),
    _: None = Depends(check_read),
) -> dict:
    tenant_id: str = request.state.tenant_id
    section_code = _validate_section_code(section_code)
    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    res = await db.execute(
        select(ReportSectionPhoto)
        .where(
            ReportSectionPhoto.tenant_id == tenant_id,
            ReportSectionPhoto.report_id == report_id,
            ReportSectionPhoto.section_code == section_code,
        )
        .order_by(ReportSectionPhoto.created_at.asc())
    )
    rows = res.scalars().all()
    max_ai = int(settings.max_section_photos_for_ai)
    selected_count = sum(1 for r in rows if getattr(r, "selected_for_ai", False))
    return {
        "report_id": report_id,
        "section_code": section_code,
        "max_photos_per_section": int(settings.max_section_photos_per_section),
        "max_photos_for_ai": max_ai,
        "selected_for_ai_count": selected_count,
        "photos": [_photo_item_dict(str(report_id), section_code, r) for r in rows],
    }


@router.put(
    "/reports/{report_id}/sections/{section_code}/photos/ai-selection",
    summary="Select which section photos are sent to AI vision (max 2)",
)
async def set_section_photo_ai_selection(
    report_id: str,
    section_code: str,
    body: SectionPhotoAiSelectionRequest,
    request: Request,
    db: AsyncSession = Depends(get_db),
) -> dict:
    """Mark up to ``max_section_photos_for_ai`` photos for AI analysis on generation."""
    tenant_id: str = request.state.tenant_id
    section_code = _validate_section_code(section_code)

    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    max_ai = int(settings.max_section_photos_for_ai)
    requested = [str(pid).strip() for pid in (body.photo_ids or []) if str(pid).strip()]
    if len(requested) > max_ai:
        raise HTTPException(
            status_code=422,
            detail=f"At most {max_ai} photo(s) may be selected for AI analysis per section.",
        )
    if len(requested) != len(set(requested)):
        raise HTTPException(status_code=422, detail="Duplicate photo_ids in selection.")

    res = await db.execute(
        select(ReportSectionPhoto).where(
            ReportSectionPhoto.tenant_id == tenant_id,
            ReportSectionPhoto.report_id == report_id,
            ReportSectionPhoto.section_code == section_code,
        )
    )
    rows = list(res.scalars().all())
    by_id = {r.id: r for r in rows}
    missing = [pid for pid in requested if pid not in by_id]
    if missing:
        raise HTTPException(
            status_code=422,
            detail=f"Unknown photo_id(s) for this section: {', '.join(missing[:5])}",
        )

    selected_set = set(requested)
    for row in rows:
        row.selected_for_ai = row.id in selected_set
    await db.commit()

    return {
        "report_id": report_id,
        "section_code": section_code,
        "selected_photo_ids": requested,
        "selected_for_ai_count": len(requested),
        "max_photos_for_ai": max_ai,
        "photos": [_photo_item_dict(str(report_id), section_code, r) for r in rows],
    }


@router.get(
    "/reports/{report_id}/sections/{section_code}/photos/{photo_id}",
    summary="Download one uploaded photo (bytes)",
)
async def get_section_photo(
    report_id: str,
    section_code: str,
    photo_id: str,
    request: Request,
    db: AsyncSession = Depends(get_db),
    _: None = Depends(check_read),
) -> FileResponse:
    tenant_id: str = request.state.tenant_id
    section_code = _validate_section_code(section_code)
    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    row = await db.get(ReportSectionPhoto, photo_id)
    if row is None or row.tenant_id != tenant_id or row.report_id != report_id or row.section_code != section_code:
        raise HTTPException(status_code=404, detail="Photo not found")

    resolved = resolve_report_photo_path(
        row.file_path,
        tenant_id=tenant_id,
        report_id=str(report_id),
        section_code=section_code,
        photo_id=photo_id,
    )
    if resolved is None:
        raise HTTPException(status_code=404, detail="Photo file missing on disk")
    return FileResponse(path=resolved, media_type=row.content_type)


@router.delete(
    "/reports/{report_id}/sections/{section_code}/photos/{photo_id}",
    summary="Delete one uploaded photo for a report section",
)
async def delete_section_photo(
    report_id: str,
    section_code: str,
    photo_id: str,
    request: Request,
    db: AsyncSession = Depends(get_db),
) -> dict:
    tenant_id: str = request.state.tenant_id
    section_code = _validate_section_code(section_code)
    report = await db.get(Report, report_id)
    if report is None or report.tenant_id != tenant_id:
        raise HTTPException(status_code=404, detail="Report not found")

    row = await db.get(ReportSectionPhoto, photo_id)
    if row is None or row.tenant_id != tenant_id or row.report_id != report_id or row.section_code != section_code:
        raise HTTPException(status_code=404, detail="Photo not found")

    resolved = resolve_report_photo_path(
        row.file_path,
        tenant_id=tenant_id,
        report_id=str(report_id),
        section_code=section_code,
        photo_id=photo_id,
    )
    file_removed = False
    if resolved is not None:
        try:
            Path(resolved).unlink(missing_ok=True)
            file_removed = True
        except OSError as exc:
            logger.warning("Could not delete photo file %s: %s", resolved, exc)

    await db.execute(delete(ReportSectionPhoto).where(ReportSectionPhoto.id == photo_id))
    await db.commit()

    return {
        "report_id": report_id,
        "section_code": section_code,
        "photo_id": photo_id,
        "removed": True,
        "file_removed": file_removed,
    }