"""Corporate memory endpoints — knowledge items, voting, governance admin."""

import uuid
from typing import Optional, List

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
import duckdb

from app.auth.access import require_admin
from app.auth.dependencies import get_current_user, _get_db
from src.repositories.knowledge import KnowledgeRepository
from src.repositories.audit import AuditRepository

router = APIRouter(prefix="/api/memory", tags=["memory"])

VALID_STATUSES = ["pending", "approved", "mandatory", "rejected", "revoked", "expired"]


class CreateKnowledgeRequest(BaseModel):
    title: str
    content: str
    category: str
    tags: Optional[List[str]] = None


class VoteRequest(BaseModel):
    vote: int


class AdminActionRequest(BaseModel):
    reason: Optional[str] = None
    audience: Optional[str] = None


class EditRequest(BaseModel):
    title: Optional[str] = None
    content: Optional[str] = None


class BatchActionRequest(BaseModel):
    item_ids: List[str]
    action: str  # approve, reject, mandate, revoke
    reason: Optional[str] = None
    audience: Optional[str] = None


# ---- User endpoints ----

@router.get("")
async def list_knowledge(
    status_filter: Optional[str] = None,
    category: Optional[str] = None,
    search: Optional[str] = None,
    page: int = 1,
    per_page: int = 50,
    sort: str = "updated_at",
    user: dict = Depends(get_current_user),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """List knowledge items with filtering, pagination, search."""
    repo = KnowledgeRepository(conn)
    offset = (page - 1) * per_page
    if search:
        items = repo.search(search)
    else:
        statuses = [status_filter] if status_filter else None
        items = repo.list_items(statuses=statuses, category=category, limit=per_page, offset=offset)

    # Enrich with votes
    for item in items:
        votes = repo.get_votes(item["id"])
        item["upvotes"] = votes["upvotes"]
        item["downvotes"] = votes["downvotes"]
        item["score"] = votes["upvotes"] - votes["downvotes"]

    return {"items": items, "count": len(items), "page": page, "per_page": per_page}


@router.get("/stats")
async def get_stats(
    user: dict = Depends(get_current_user),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """Get corporate memory statistics."""
    rows = conn.execute(
        "SELECT status, category, COUNT(*) as n FROM knowledge_items GROUP BY status, category"
    ).fetchall()

    status_counts: dict[str, int] = {}
    categories: set[str] = set()
    total = 0
    for status, category, n in rows:
        status_counts[status] = status_counts.get(status, 0) + n
        if category:
            categories.add(category)
        total += n
    return {"total": total, "by_status": status_counts, "categories": sorted(categories)}


@router.post("", status_code=201)
async def create_knowledge(
    request: CreateKnowledgeRequest,
    user: dict = Depends(get_current_user),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    item_id = str(uuid.uuid4())
    repo.create(
        id=item_id,
        title=request.title,
        content=request.content,
        category=request.category,
        source_user=user.get("email"),
        tags=request.tags,
    )
    return {"id": item_id, "status": "pending"}


@router.post("/{item_id}/vote")
async def vote_knowledge(
    item_id: str,
    request: VoteRequest,
    user: dict = Depends(get_current_user),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    if request.vote not in (1, -1):
        raise HTTPException(status_code=400, detail="Vote must be 1 or -1")
    repo = KnowledgeRepository(conn)
    if not repo.get_by_id(item_id):
        raise HTTPException(status_code=404, detail="Knowledge item not found")
    repo.vote(item_id, user["id"], request.vote)
    return repo.get_votes(item_id)


@router.get("/my-votes")
async def get_my_votes(
    user: dict = Depends(get_current_user),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """Get current user's votes on all items."""
    results = conn.execute(
        "SELECT item_id, vote FROM knowledge_votes WHERE user_id = ?", [user["id"]]
    ).fetchall()
    return {row[0]: row[1] for row in results}


# ---- Admin governance endpoints ----

def _get_item_or_404(repo: KnowledgeRepository, item_id: str) -> dict:
    item = repo.get_by_id(item_id)
    if not item:
        raise HTTPException(status_code=404, detail="Knowledge item not found")
    return item


def _audit_action(conn, admin_email: str, action: str, item_id: str, details: dict = None):
    audit = AuditRepository(conn)
    audit.log(user_id=admin_email, action=f"km_{action}", resource=item_id, params=details)


@router.post("/admin/approve")
async def admin_approve(
    item_id: str,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    _get_item_or_404(repo, item_id)
    repo.update_status(item_id, "approved")
    _audit_action(conn, user["email"], "approve", item_id)
    return {"id": item_id, "status": "approved"}


@router.post("/admin/reject")
async def admin_reject(
    item_id: str,
    request: AdminActionRequest,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    _get_item_or_404(repo, item_id)
    repo.update_status(item_id, "rejected")
    _audit_action(conn, user["email"], "reject", item_id, {"reason": request.reason})
    return {"id": item_id, "status": "rejected"}


@router.post("/admin/mandate")
async def admin_mandate(
    item_id: str,
    request: AdminActionRequest,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    _get_item_or_404(repo, item_id)
    repo.update_status(item_id, "mandatory")
    _audit_action(conn, user["email"], "mandate", item_id, {
        "reason": request.reason, "audience": request.audience,
    })
    return {"id": item_id, "status": "mandatory"}


@router.post("/admin/revoke")
async def admin_revoke(
    item_id: str,
    request: AdminActionRequest,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    _get_item_or_404(repo, item_id)
    repo.update_status(item_id, "revoked")
    _audit_action(conn, user["email"], "revoke", item_id, {"reason": request.reason})
    return {"id": item_id, "status": "revoked"}


@router.post("/admin/edit")
async def admin_edit(
    item_id: str,
    request: EditRequest,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    repo = KnowledgeRepository(conn)
    _get_item_or_404(repo, item_id)
    updates = {}
    if request.title is not None:
        updates["title"] = request.title
    if request.content is not None:
        updates["content"] = request.content
    if updates:
        repo.update(item_id, **updates)
    _audit_action(conn, user["email"], "edit", item_id, updates)
    return {"id": item_id, "updated": list(updates.keys())}


@router.post("/admin/batch")
async def admin_batch(
    request: BatchActionRequest,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """Batch governance action on multiple items."""
    repo = KnowledgeRepository(conn)
    action_map = {
        "approve": "approved",
        "reject": "rejected",
        "mandate": "mandatory",
        "revoke": "revoked",
    }
    if request.action not in action_map:
        raise HTTPException(status_code=400, detail=f"Invalid action: {request.action}")

    new_status = action_map[request.action]
    results = {"success": [], "not_found": []}
    for item_id in request.item_ids:
        item = repo.get_by_id(item_id)
        if not item:
            results["not_found"].append(item_id)
            continue
        repo.update_status(item_id, new_status)
        _audit_action(conn, user["email"], request.action, item_id, {
            "reason": request.reason, "audience": request.audience, "batch": True,
        })
        results["success"].append(item_id)

    return results


@router.get("/admin/pending")
async def admin_pending(
    category: Optional[str] = None,
    page: int = 1,
    per_page: int = 50,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """Get pending items queue for admin review."""
    repo = KnowledgeRepository(conn)
    offset = (page - 1) * per_page
    items = repo.list_items(statuses=["pending"], category=category, limit=per_page, offset=offset)
    return {"items": items, "count": len(items)}


@router.get("/admin/audit")
async def admin_audit(
    page: int = 1,
    per_page: int = 50,
    action: Optional[str] = None,
    user: dict = Depends(require_admin),
    conn: duckdb.DuckDBPyConnection = Depends(_get_db),
):
    """Get governance audit log."""
    audit = AuditRepository(conn)
    # Filter km_ prefixed actions
    km_action = f"km_{action}" if action else None
    entries = audit.query(action=km_action, limit=per_page)
    if not km_action:
        # Get all km_ actions
        entries = conn.execute(
            "SELECT * FROM audit_log WHERE action LIKE 'km_%' ORDER BY timestamp DESC LIMIT ?",
            [per_page],
        ).fetchall()
        if entries:
            columns = [desc[0] for desc in conn.description]
            entries = [dict(zip(columns, row)) for row in entries]
        else:
            entries = []
    return {"entries": entries, "count": len(entries)}