"""Client document upload and AI matching endpoints."""

import logging

from fastapi import APIRouter, BackgroundTasks, Depends, HTTPException, UploadFile, File
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db, async_session
from app.models.gmal import GmalAsset
from app.models.project import Project, ClientAsset, Match, ProjectStatus, MatchConfidence
from app.schemas.project import ClientAssetOut, ClientAssetUpdate, MatchOut, MatchSelectRequest, ManualMatchRequest
from app.services.doc_parser import extract_text_from_file, parse_text_with_ai
from app.services.ai_matching import match_client_assets

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


async def _background_parse(project_id: int, filename: str, text: str, metadata: dict):
    """Run AI parsing and save results in the background (own DB session)."""
    async with async_session() as db:
        try:
            result = await db.execute(select(Project).where(Project.id == project_id))
            project = result.scalar_one_or_none()
            if not project:
                return

            # Stage 3: AI parsing
            try:
                extracted, usage_info = parse_text_with_ai(text)
            except Exception as e:
                logger.error(f"AI parsing failed for project {project_id}: {e}")
                project.status = ProjectStatus.DRAFT
                project.parse_stage = f"AI parsing failed: {str(e)}"
                await db.commit()
                return

            # Save AI costs
            project.ai_input_tokens = (project.ai_input_tokens or 0) + usage_info.get("input_tokens", 0)
            project.ai_output_tokens = (project.ai_output_tokens or 0) + usage_info.get("output_tokens", 0)
            project.ai_cost_usd = float(project.ai_cost_usd or 0) + usage_info.get("cost_usd", 0)
            project.ai_call_count = (project.ai_call_count or 0) + 1

            # Stage 4: Saving results
            project.parse_stage = f"AI found {len(extracted)} assets. Saving..."
            await db.commit()

            # Clear existing client assets
            existing = await db.execute(
                select(ClientAsset).where(ClientAsset.project_id == project_id)
            )
            for ca in existing.scalars().all():
                await db.delete(ca)

            # Create client asset records (skip zero-quantity assets)
            assets = []
            for idx, item in enumerate(extracted):
                volume = item.get("volume", 1)
                if volume <= 0:
                    continue
                ca = ClientAsset(
                    project_id=project_id,
                    raw_name=item.get("name", "Unknown"),
                    raw_description=item.get("description", ""),
                    volume=volume,
                    sort_order=idx + 1,
                )
                db.add(ca)
                assets.append(ca)

            project.status = ProjectStatus.REVIEW
            project.parse_stage = f"Done! {len(assets)} assets extracted."
            await db.commit()
            logger.info(f"Background parse complete for project {project_id}: {len(assets)} assets")

        except Exception as e:
            logger.error(f"Background parse error for project {project_id}: {e}")


@router.post("/{project_id}/upload")
async def upload_client_document(
    project_id: int,
    background_tasks: BackgroundTasks,
    file: UploadFile = File(...),
    db: AsyncSession = Depends(get_db),
):
    """Upload a client document and extract assets using AI."""
    project = await _get_project(project_id, db)

    # Stage 1: Read file and save to data dir
    import os
    from app.config import settings
    content = await file.read()
    save_path = os.path.join(settings.data_dir, file.filename)
    with open(save_path, "wb") as f:
        f.write(content)
    project.source_filename = file.filename
    project.status = ProjectStatus.PARSING
    project.parse_stage = f"Uploading {file.filename}..."
    await db.commit()

    # Stage 2: Extract text (fast, synchronous)
    project.parse_stage = "Extracting text from document..."
    await db.commit()

    try:
        text, metadata = extract_text_from_file(content, file.filename)
    except Exception as e:
        project.status = ProjectStatus.DRAFT
        project.parse_stage = None
        await db.commit()
        raise HTTPException(status_code=400, detail=f"Failed to extract text: {str(e)}")

    sheets_info = f" ({metadata['sheet_count']} sheets)" if metadata['sheet_count'] else ""
    project.parse_stage = f"Extracted {metadata['char_count']:,} characters{sheets_info}. Sending to AI..."
    await db.commit()

    # Stage 3+4: AI parsing runs in background — return 202 immediately
    background_tasks.add_task(_background_parse, project_id, file.filename, text, metadata)

    return {
        "message": f"Document received. AI parsing started for {file.filename}.",
        "status": "parsing",
    }


@router.get("/{project_id}/brief-analysis")
async def get_brief_analysis(project_id: int, db: AsyncSession = Depends(get_db)):
    """Get the structured brief analysis for a project."""
    project = await _get_project(project_id, db)
    if not project.brief_analysis:
        return {"status": "not_analyzed"}
    import json
    try:
        return {"status": "analyzed", "analysis": json.loads(project.brief_analysis)}
    except json.JSONDecodeError:
        return {"status": "error", "analysis": None}


@router.post("/{project_id}/analyze-brief")
async def analyze_brief_endpoint(project_id: int, db: AsyncSession = Depends(get_db)):
    """Run AI analysis on the uploaded document."""
    from app.services.rfp_analysis import analyze_brief
    from app.services.doc_parser import extract_text_from_file

    project = await _get_project(project_id, db)
    if not project.source_filename:
        raise HTTPException(status_code=400, detail="No document uploaded yet")

    # Read the file from data dir
    import os
    from app.config import settings
    filepath = os.path.join(settings.data_dir, project.source_filename)

    # Try to read from the stored file - if not available, re-extract from any recent upload
    # For now, we store the extracted text in parse_stage temporarily during upload
    # We need the raw text - let's store it
    if not os.path.exists(filepath):
        return {"status": "error", "detail": "Source file not found on disk. Re-upload the document."}

    with open(filepath, "rb") as f:
        content = f.read()

    text, metadata = extract_text_from_file(content, project.source_filename)
    analysis = await analyze_brief(db, project, text)
    return {"status": "analyzed", "analysis": analysis}


@router.get("/{project_id}/client-assets", response_model=list[ClientAssetOut])
async def list_client_assets(project_id: int, db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(ClientAsset)
        .where(ClientAsset.project_id == project_id)
        .order_by(ClientAsset.sort_order)
    )
    return result.scalars().all()


@router.put("/{project_id}/client-assets/{asset_id}", response_model=ClientAssetOut)
async def update_client_asset(
    project_id: int,
    asset_id: int,
    data: ClientAssetUpdate,
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(
        select(ClientAsset).where(ClientAsset.id == asset_id, ClientAsset.project_id == project_id)
    )
    ca = result.scalar_one_or_none()
    if not ca:
        raise HTTPException(status_code=404, detail="Client asset not found")

    if data.raw_name is not None:
        ca.raw_name = data.raw_name
    if data.raw_description is not None:
        ca.raw_description = data.raw_description
    if data.volume is not None:
        ca.volume = data.volume

    await db.commit()
    await db.refresh(ca)
    return ca


async def _background_match(project_id: int, asset_snapshots: list):
    """Run AI matching in the background (own DB session)."""
    async with async_session() as db:
        try:
            result = await db.execute(select(Project).where(Project.id == project_id))
            project = result.scalar_one_or_none()
            if not project:
                return

            # Reconstruct ClientAsset-like objects from snapshots for match_client_assets
            ca_result = await db.execute(
                select(ClientAsset).where(ClientAsset.id.in_([s["id"] for s in asset_snapshots]))
                .order_by(ClientAsset.sort_order)
            )
            client_assets = ca_result.scalars().all()

            matches = await match_client_assets(db, project_id, client_assets)

            await db.refresh(project)
            project.status = ProjectStatus.REVIEW
            await db.commit()
            logger.info(f"Background match complete for project {project_id}: {len(matches)} matches")

        except Exception as e:
            logger.error(f"Background match error for project {project_id}: {e}")
            try:
                async with async_session() as db2:
                    result = await db2.execute(select(Project).where(Project.id == project_id))
                    project = result.scalar_one_or_none()
                    if project:
                        project.status = ProjectStatus.REVIEW
                        await db2.commit()
            except Exception:
                pass


@router.post("/{project_id}/match")
async def run_matching(
    project_id: int,
    background_tasks: BackgroundTasks,
    db: AsyncSession = Depends(get_db),
):
    """Trigger AI matching for all client assets in this project."""
    project = await _get_project(project_id, db)

    # Get client assets
    result = await db.execute(
        select(ClientAsset).where(ClientAsset.project_id == project_id).order_by(ClientAsset.sort_order)
    )
    client_assets = result.scalars().all()

    if not client_assets:
        raise HTTPException(status_code=400, detail="No client assets to match. Upload a document first.")

    # Snapshot IDs before clearing (ORM objects expire after commit)
    asset_snapshots = [{"id": ca.id} for ca in client_assets]

    # Clear existing matches
    for ca in client_assets:
        matches_result = await db.execute(select(Match).where(Match.client_asset_id == ca.id))
        for m in matches_result.scalars().all():
            await db.delete(m)

    project.status = ProjectStatus.MATCHING
    await db.commit()

    # Run matching in background — return 202 immediately
    background_tasks.add_task(_background_match, project_id, asset_snapshots)

    return {
        "message": f"Matching started for {len(client_assets)} client assets.",
        "status": "matching",
    }


@router.post("/{project_id}/match/cancel")
async def cancel_matching_endpoint(project_id: int, db: AsyncSession = Depends(get_db)):
    """Cancel an in-progress matching run."""
    from app.services.ai_matching import cancel_matching
    cancel_matching(project_id)
    project = await _get_project(project_id, db)
    project.status = ProjectStatus.REVIEW
    await db.commit()
    return {"detail": "Matching cancellation requested"}


@router.post("/{project_id}/refine")
async def refine_matches_endpoint(
    project_id: int,
    data: dict,
    db: AsyncSession = Depends(get_db),
):
    """Interpret a natural language instruction to refine matches."""
    from app.services.match_refiner import refine_matches
    instruction = data.get("instruction", "")
    if not instruction:
        raise HTTPException(status_code=400, detail="No instruction provided")

    result = await refine_matches(db, project_id, instruction)

    # If there are assets to re-match, trigger matching for just those
    if result.get("rematch_count", 0) > 0:
        rematch_ids = result["rematch_asset_ids"]
        ca_result = await db.execute(
            select(ClientAsset).where(ClientAsset.id.in_(rematch_ids)).order_by(ClientAsset.sort_order)
        )
        client_assets = ca_result.scalars().all()
        if client_assets:
            matches = await match_client_assets(db, project_id, client_assets)
            result["new_matches"] = len(matches)

    return result


@router.post("/{project_id}/matches/{match_id}/feedback")
async def submit_match_feedback(
    project_id: int,
    match_id: int,
    data: dict,
    db: AsyncSession = Depends(get_db),
):
    """Store feedback on a match (confirm or reject) for the learning system."""
    from app.models.feedback import MatchFeedback

    result = await db.execute(select(Match).where(Match.id == match_id))
    match = result.scalar_one_or_none()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")

    # Get the client asset name for the feedback record
    ca_result = await db.execute(select(ClientAsset).where(ClientAsset.id == match.client_asset_id))
    ca = ca_result.scalar_one_or_none()

    confirmed = data.get("confirmed", True)
    comment = data.get("comment", "")

    feedback = MatchFeedback(
        client_term=(ca.raw_name or "").strip().lower() if ca else "",
        client_description=ca.raw_description if ca else None,
        gmal_asset_id=match.gmal_asset_id,
        confirmed=confirmed,
        user_comment=comment,
    )
    db.add(feedback)
    await db.commit()

    return {"detail": f"Feedback {'confirmed' if confirmed else 'rejected'} stored"}


@router.get("/{project_id}/matches", response_model=list[MatchOut])
async def list_matches(project_id: int, db: AsyncSession = Depends(get_db)):
    """Get all matches for a project, grouped by client asset."""
    # Get client asset IDs for this project
    ca_result = await db.execute(
        select(ClientAsset.id).where(ClientAsset.project_id == project_id)
    )
    ca_ids = [r[0] for r in ca_result.all()]

    if not ca_ids:
        return []

    result = await db.execute(
        select(Match, GmalAsset)
        .join(GmalAsset, Match.gmal_asset_id == GmalAsset.id)
        .where(Match.client_asset_id.in_(ca_ids))
        .order_by(Match.client_asset_id, Match.rank)
    )

    matches = []
    for match, gmal in result.all():
        matches.append(MatchOut(
            id=match.id,
            client_asset_id=match.client_asset_id,
            gmal_asset_id=match.gmal_asset_id,
            gmal_id=gmal.gmal_id,
            gmal_name=gmal.asset_name,
            gmal_unique_name=gmal.unique_name,
            confidence=match.confidence.value,
            confidence_score=float(match.confidence_score) if match.confidence_score else None,
            ai_reasoning=match.ai_reasoning,
            caveat_text=match.caveat_text,
            is_selected=match.is_selected,
            rank=match.rank,
        ))

    return matches


@router.put("/{project_id}/matches/{match_id}/select")
async def select_match(
    project_id: int,
    match_id: int,
    data: MatchSelectRequest,
    db: AsyncSession = Depends(get_db),
):
    """Select or deselect a match. Deselects other matches for the same client asset."""
    result = await db.execute(select(Match).where(Match.id == match_id))
    match = result.scalar_one_or_none()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")

    if data.is_selected:
        # Deselect all other matches for this client asset
        siblings = await db.execute(
            select(Match).where(Match.client_asset_id == match.client_asset_id)
        )
        for sibling in siblings.scalars().all():
            sibling.is_selected = False

    match.is_selected = data.is_selected
    await db.commit()

    return {"detail": "Match updated"}


@router.post("/{project_id}/matches/{client_asset_id}/manual")
async def manual_match(
    project_id: int,
    client_asset_id: int,
    data: ManualMatchRequest,
    db: AsyncSession = Depends(get_db),
):
    """Manually assign a GMAL asset to a client asset."""
    # Verify client asset belongs to project
    ca_result = await db.execute(
        select(ClientAsset).where(ClientAsset.id == client_asset_id, ClientAsset.project_id == project_id)
    )
    ca = ca_result.scalar_one_or_none()
    if not ca:
        raise HTTPException(status_code=404, detail="Client asset not found")

    # Verify GMAL asset exists
    gmal_result = await db.execute(select(GmalAsset).where(GmalAsset.id == data.gmal_asset_id))
    gmal = gmal_result.scalar_one_or_none()
    if not gmal:
        raise HTTPException(status_code=404, detail="GMAL asset not found")

    # Deselect existing matches
    existing = await db.execute(select(Match).where(Match.client_asset_id == client_asset_id))
    for m in existing.scalars().all():
        m.is_selected = False

    # Create manual match
    match = Match(
        client_asset_id=client_asset_id,
        gmal_asset_id=data.gmal_asset_id,
        confidence=MatchConfidence.EXACT,
        confidence_score=1.0,
        ai_reasoning="Manually assigned by user",
        caveat_text="",
        is_selected=True,
        rank=0,
    )
    db.add(match)
    await db.commit()

    return {"detail": f"Manually matched to {gmal.gmal_id}"}


async def _get_project(project_id: int, db: AsyncSession) -> Project:
    result = await db.execute(select(Project).where(Project.id == project_id))
    project = result.scalar_one_or_none()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")
    return project