"""
EduSearch Seeds API Routes.

CRUD operations for managing education search crawler seed URLs.
Direct database access to PostgreSQL.
"""

import os
import logging
from typing import Optional, List
from datetime import datetime
from uuid import UUID

from fastapi import APIRouter, HTTPException, Depends, Query
from pydantic import BaseModel, Field, HttpUrl
import asyncpg

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/edu-search", tags=["edu-search"])

# Database connection pool
_pool: Optional[asyncpg.Pool] = None


async def get_db_pool() -> asyncpg.Pool:
    """Get or create database connection pool."""
    global _pool
    if _pool is None:
        database_url = os.environ.get("DATABASE_URL")
        if not database_url:
            raise RuntimeError("DATABASE_URL nicht konfiguriert - bitte via Vault oder Umgebungsvariable setzen")
        _pool = await asyncpg.create_pool(database_url, min_size=2, max_size=10)
    return _pool


# =============================================================================
# Pydantic Models
# =============================================================================


class CategoryResponse(BaseModel):
    """Category response model."""
    id: str
    name: str
    display_name: str
    description: Optional[str] = None
    icon: Optional[str] = None
    sort_order: int
    is_active: bool


class SeedBase(BaseModel):
    """Base seed model for creation/update."""
    url: str = Field(..., max_length=500)
    name: str = Field(..., max_length=255)
    description: Optional[str] = None
    category_name: Optional[str] = Field(None, description="Category name (federal, states, etc.)")
    source_type: str = Field("GOV", description="GOV, EDU, UNI, etc.")
    scope: str = Field("FEDERAL", description="FEDERAL, STATE, etc.")
    state: Optional[str] = Field(None, max_length=5, description="State code (BW, BY, etc.)")
    trust_boost: float = Field(0.50, ge=0.0, le=1.0)
    enabled: bool = True
    crawl_depth: int = Field(2, ge=1, le=5)
    crawl_frequency: str = Field("weekly", description="hourly, daily, weekly, monthly")


class SeedCreate(SeedBase):
    """Seed creation model."""
    pass


class SeedUpdate(BaseModel):
    """Seed update model (all fields optional)."""
    url: Optional[str] = Field(None, max_length=500)
    name: Optional[str] = Field(None, max_length=255)
    description: Optional[str] = None
    category_name: Optional[str] = None
    source_type: Optional[str] = None
    scope: Optional[str] = None
    state: Optional[str] = Field(None, max_length=5)
    trust_boost: Optional[float] = Field(None, ge=0.0, le=1.0)
    enabled: Optional[bool] = None
    crawl_depth: Optional[int] = Field(None, ge=1, le=5)
    crawl_frequency: Optional[str] = None


class SeedResponse(BaseModel):
    """Seed response model."""
    id: str
    url: str
    name: str
    description: Optional[str] = None
    category: Optional[str] = None
    category_display_name: Optional[str] = None
    source_type: str
    scope: str
    state: Optional[str] = None
    trust_boost: float
    enabled: bool
    crawl_depth: int
    crawl_frequency: str
    last_crawled_at: Optional[datetime] = None
    last_crawl_status: Optional[str] = None
    last_crawl_docs: int = 0
    total_documents: int = 0
    created_at: datetime
    updated_at: datetime


class SeedsListResponse(BaseModel):
    """List response with pagination info."""
    seeds: List[SeedResponse]
    total: int
    page: int
    page_size: int


class StatsResponse(BaseModel):
    """Crawl statistics response."""
    total_seeds: int
    enabled_seeds: int
    total_documents: int
    seeds_by_category: dict
    seeds_by_state: dict
    last_crawl_time: Optional[datetime] = None


class BulkImportRequest(BaseModel):
    """Bulk import request."""
    seeds: List[SeedCreate]


class BulkImportResponse(BaseModel):
    """Bulk import response."""
    imported: int
    skipped: int
    errors: List[str]


# =============================================================================
# API Endpoints
# =============================================================================


@router.get("/categories", response_model=List[CategoryResponse])
async def list_categories():
    """List all seed categories."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        rows = await conn.fetch("""
            SELECT id, name, display_name, description, icon, sort_order, is_active
            FROM edu_search_categories
            WHERE is_active = TRUE
            ORDER BY sort_order
        """)
        return [
            CategoryResponse(
                id=str(row["id"]),
                name=row["name"],
                display_name=row["display_name"],
                description=row["description"],
                icon=row["icon"],
                sort_order=row["sort_order"],
                is_active=row["is_active"],
            )
            for row in rows
        ]


@router.get("/seeds", response_model=SeedsListResponse)
async def list_seeds(
    category: Optional[str] = Query(None, description="Filter by category name"),
    state: Optional[str] = Query(None, description="Filter by state code"),
    enabled: Optional[bool] = Query(None, description="Filter by enabled status"),
    search: Optional[str] = Query(None, description="Search in name/url"),
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
):
    """List seeds with optional filtering and pagination."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        # Build WHERE clause
        conditions = []
        params = []
        param_idx = 1

        if category:
            conditions.append(f"c.name = ${param_idx}")
            params.append(category)
            param_idx += 1

        if state:
            conditions.append(f"s.state = ${param_idx}")
            params.append(state)
            param_idx += 1

        if enabled is not None:
            conditions.append(f"s.enabled = ${param_idx}")
            params.append(enabled)
            param_idx += 1

        if search:
            conditions.append(f"(s.name ILIKE ${param_idx} OR s.url ILIKE ${param_idx})")
            params.append(f"%{search}%")
            param_idx += 1

        where_clause = " AND ".join(conditions) if conditions else "TRUE"

        # Count total
        count_query = f"""
            SELECT COUNT(*) FROM edu_search_seeds s
            LEFT JOIN edu_search_categories c ON s.category_id = c.id
            WHERE {where_clause}
        """
        total = await conn.fetchval(count_query, *params)

        # Get paginated results
        offset = (page - 1) * page_size
        params.extend([page_size, offset])

        query = f"""
            SELECT
                s.id, s.url, s.name, s.description,
                c.name as category, c.display_name as category_display_name,
                s.source_type, s.scope, s.state, s.trust_boost, s.enabled,
                s.crawl_depth, s.crawl_frequency, s.last_crawled_at,
                s.last_crawl_status, s.last_crawl_docs, s.total_documents,
                s.created_at, s.updated_at
            FROM edu_search_seeds s
            LEFT JOIN edu_search_categories c ON s.category_id = c.id
            WHERE {where_clause}
            ORDER BY c.sort_order, s.name
            LIMIT ${param_idx} OFFSET ${param_idx + 1}
        """

        rows = await conn.fetch(query, *params)

        seeds = [
            SeedResponse(
                id=str(row["id"]),
                url=row["url"],
                name=row["name"],
                description=row["description"],
                category=row["category"],
                category_display_name=row["category_display_name"],
                source_type=row["source_type"],
                scope=row["scope"],
                state=row["state"],
                trust_boost=float(row["trust_boost"]),
                enabled=row["enabled"],
                crawl_depth=row["crawl_depth"],
                crawl_frequency=row["crawl_frequency"],
                last_crawled_at=row["last_crawled_at"],
                last_crawl_status=row["last_crawl_status"],
                last_crawl_docs=row["last_crawl_docs"] or 0,
                total_documents=row["total_documents"] or 0,
                created_at=row["created_at"],
                updated_at=row["updated_at"],
            )
            for row in rows
        ]

        return SeedsListResponse(
            seeds=seeds,
            total=total,
            page=page,
            page_size=page_size,
        )


@router.get("/seeds/{seed_id}", response_model=SeedResponse)
async def get_seed(seed_id: str):
    """Get a single seed by ID."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        row = await conn.fetchrow("""
            SELECT
                s.id, s.url, s.name, s.description,
                c.name as category, c.display_name as category_display_name,
                s.source_type, s.scope, s.state, s.trust_boost, s.enabled,
                s.crawl_depth, s.crawl_frequency, s.last_crawled_at,
                s.last_crawl_status, s.last_crawl_docs, s.total_documents,
                s.created_at, s.updated_at
            FROM edu_search_seeds s
            LEFT JOIN edu_search_categories c ON s.category_id = c.id
            WHERE s.id = $1
        """, seed_id)

        if not row:
            raise HTTPException(status_code=404, detail="Seed nicht gefunden")

        return SeedResponse(
            id=str(row["id"]),
            url=row["url"],
            name=row["name"],
            description=row["description"],
            category=row["category"],
            category_display_name=row["category_display_name"],
            source_type=row["source_type"],
            scope=row["scope"],
            state=row["state"],
            trust_boost=float(row["trust_boost"]),
            enabled=row["enabled"],
            crawl_depth=row["crawl_depth"],
            crawl_frequency=row["crawl_frequency"],
            last_crawled_at=row["last_crawled_at"],
            last_crawl_status=row["last_crawl_status"],
            last_crawl_docs=row["last_crawl_docs"] or 0,
            total_documents=row["total_documents"] or 0,
            created_at=row["created_at"],
            updated_at=row["updated_at"],
        )


@router.post("/seeds", response_model=SeedResponse, status_code=201)
async def create_seed(seed: SeedCreate):
    """Create a new seed URL."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        # Get category ID if provided
        category_id = None
        if seed.category_name:
            category_id = await conn.fetchval(
                "SELECT id FROM edu_search_categories WHERE name = $1",
                seed.category_name
            )

        try:
            row = await conn.fetchrow("""
                INSERT INTO edu_search_seeds (
                    url, name, description, category_id, source_type, scope,
                    state, trust_boost, enabled, crawl_depth, crawl_frequency
                ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
                RETURNING id, created_at, updated_at
            """,
                seed.url, seed.name, seed.description, category_id,
                seed.source_type, seed.scope, seed.state, seed.trust_boost,
                seed.enabled, seed.crawl_depth, seed.crawl_frequency
            )
        except asyncpg.UniqueViolationError:
            raise HTTPException(status_code=409, detail="URL existiert bereits")

        return SeedResponse(
            id=str(row["id"]),
            url=seed.url,
            name=seed.name,
            description=seed.description,
            category=seed.category_name,
            category_display_name=None,
            source_type=seed.source_type,
            scope=seed.scope,
            state=seed.state,
            trust_boost=seed.trust_boost,
            enabled=seed.enabled,
            crawl_depth=seed.crawl_depth,
            crawl_frequency=seed.crawl_frequency,
            last_crawled_at=None,
            last_crawl_status=None,
            last_crawl_docs=0,
            total_documents=0,
            created_at=row["created_at"],
            updated_at=row["updated_at"],
        )


@router.put("/seeds/{seed_id}", response_model=SeedResponse)
async def update_seed(seed_id: str, seed: SeedUpdate):
    """Update an existing seed."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        # Build update statement dynamically
        updates = []
        params = []
        param_idx = 1

        if seed.url is not None:
            updates.append(f"url = ${param_idx}")
            params.append(seed.url)
            param_idx += 1

        if seed.name is not None:
            updates.append(f"name = ${param_idx}")
            params.append(seed.name)
            param_idx += 1

        if seed.description is not None:
            updates.append(f"description = ${param_idx}")
            params.append(seed.description)
            param_idx += 1

        if seed.category_name is not None:
            category_id = await conn.fetchval(
                "SELECT id FROM edu_search_categories WHERE name = $1",
                seed.category_name
            )
            updates.append(f"category_id = ${param_idx}")
            params.append(category_id)
            param_idx += 1

        if seed.source_type is not None:
            updates.append(f"source_type = ${param_idx}")
            params.append(seed.source_type)
            param_idx += 1

        if seed.scope is not None:
            updates.append(f"scope = ${param_idx}")
            params.append(seed.scope)
            param_idx += 1

        if seed.state is not None:
            updates.append(f"state = ${param_idx}")
            params.append(seed.state)
            param_idx += 1

        if seed.trust_boost is not None:
            updates.append(f"trust_boost = ${param_idx}")
            params.append(seed.trust_boost)
            param_idx += 1

        if seed.enabled is not None:
            updates.append(f"enabled = ${param_idx}")
            params.append(seed.enabled)
            param_idx += 1

        if seed.crawl_depth is not None:
            updates.append(f"crawl_depth = ${param_idx}")
            params.append(seed.crawl_depth)
            param_idx += 1

        if seed.crawl_frequency is not None:
            updates.append(f"crawl_frequency = ${param_idx}")
            params.append(seed.crawl_frequency)
            param_idx += 1

        if not updates:
            raise HTTPException(status_code=400, detail="Keine Felder zum Aktualisieren")

        updates.append("updated_at = NOW()")
        params.append(seed_id)

        query = f"""
            UPDATE edu_search_seeds
            SET {", ".join(updates)}
            WHERE id = ${param_idx}
            RETURNING id
        """

        result = await conn.fetchrow(query, *params)
        if not result:
            raise HTTPException(status_code=404, detail="Seed nicht gefunden")

        # Return updated seed
        return await get_seed(seed_id)


@router.delete("/seeds/{seed_id}")
async def delete_seed(seed_id: str):
    """Delete a seed."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        result = await conn.execute(
            "DELETE FROM edu_search_seeds WHERE id = $1",
            seed_id
        )
        if result == "DELETE 0":
            raise HTTPException(status_code=404, detail="Seed nicht gefunden")

        return {"status": "deleted", "id": seed_id}


@router.post("/seeds/bulk-import", response_model=BulkImportResponse)
async def bulk_import_seeds(request: BulkImportRequest):
    """Bulk import seeds (skip duplicates)."""
    pool = await get_db_pool()
    imported = 0
    skipped = 0
    errors = []

    async with pool.acquire() as conn:
        # Pre-fetch all category IDs
        categories = {}
        rows = await conn.fetch("SELECT id, name FROM edu_search_categories")
        for row in rows:
            categories[row["name"]] = row["id"]

        for seed in request.seeds:
            try:
                category_id = categories.get(seed.category_name) if seed.category_name else None

                await conn.execute("""
                    INSERT INTO edu_search_seeds (
                        url, name, description, category_id, source_type, scope,
                        state, trust_boost, enabled, crawl_depth, crawl_frequency
                    ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
                    ON CONFLICT (url) DO NOTHING
                """,
                    seed.url, seed.name, seed.description, category_id,
                    seed.source_type, seed.scope, seed.state, seed.trust_boost,
                    seed.enabled, seed.crawl_depth, seed.crawl_frequency
                )
                imported += 1
            except asyncpg.UniqueViolationError:
                skipped += 1
            except Exception as e:
                errors.append(f"{seed.url}: {str(e)}")

    return BulkImportResponse(imported=imported, skipped=skipped, errors=errors)


@router.get("/stats", response_model=StatsResponse)
async def get_stats():
    """Get crawl statistics."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        # Basic counts
        total = await conn.fetchval("SELECT COUNT(*) FROM edu_search_seeds")
        enabled = await conn.fetchval("SELECT COUNT(*) FROM edu_search_seeds WHERE enabled = TRUE")
        total_docs = await conn.fetchval("SELECT COALESCE(SUM(total_documents), 0) FROM edu_search_seeds")

        # By category
        cat_rows = await conn.fetch("""
            SELECT c.name, COUNT(s.id) as count
            FROM edu_search_categories c
            LEFT JOIN edu_search_seeds s ON c.id = s.category_id
            GROUP BY c.name
        """)
        by_category = {row["name"]: row["count"] for row in cat_rows}

        # By state
        state_rows = await conn.fetch("""
            SELECT COALESCE(state, 'federal') as state, COUNT(*) as count
            FROM edu_search_seeds
            GROUP BY state
        """)
        by_state = {row["state"]: row["count"] for row in state_rows}

        # Last crawl time
        last_crawl = await conn.fetchval(
            "SELECT MAX(last_crawled_at) FROM edu_search_seeds"
        )

        return StatsResponse(
            total_seeds=total,
            enabled_seeds=enabled,
            total_documents=total_docs,
            seeds_by_category=by_category,
            seeds_by_state=by_state,
            last_crawl_time=last_crawl,
        )


# Export for external use (edu-search-service)
@router.get("/seeds/export/for-crawler")
async def export_seeds_for_crawler():
    """Export enabled seeds in format suitable for crawler."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        rows = await conn.fetch("""
            SELECT
                s.url, s.trust_boost, s.source_type, s.scope, s.state,
                s.crawl_depth, c.name as category
            FROM edu_search_seeds s
            LEFT JOIN edu_search_categories c ON s.category_id = c.id
            WHERE s.enabled = TRUE
            ORDER BY s.trust_boost DESC
        """)

        return {
            "seeds": [
                {
                    "url": row["url"],
                    "trust": float(row["trust_boost"]),
                    "source": row["source_type"],
                    "scope": row["scope"],
                    "state": row["state"],
                    "depth": row["crawl_depth"],
                    "category": row["category"],
                }
                for row in rows
            ],
            "total": len(rows),
            "exported_at": datetime.utcnow().isoformat(),
        }


# =============================================================================
# Crawl Status Feedback (from edu-search-service)
# =============================================================================


class CrawlStatusUpdate(BaseModel):
    """Crawl status update from edu-search-service."""
    seed_url: str = Field(..., description="The seed URL that was crawled")
    status: str = Field(..., description="Crawl status: success, error, partial")
    documents_crawled: int = Field(0, ge=0, description="Number of documents crawled")
    error_message: Optional[str] = Field(None, description="Error message if status is error")
    crawl_duration_seconds: float = Field(0.0, ge=0.0, description="Duration of the crawl in seconds")


class CrawlStatusResponse(BaseModel):
    """Response for crawl status update."""
    success: bool
    seed_url: str
    message: str


@router.post("/seeds/crawl-status", response_model=CrawlStatusResponse)
async def update_crawl_status(update: CrawlStatusUpdate):
    """Update crawl status for a seed URL (called by edu-search-service)."""
    pool = await get_db_pool()
    async with pool.acquire() as conn:
        # Find the seed by URL
        seed = await conn.fetchrow(
            "SELECT id, total_documents FROM edu_search_seeds WHERE url = $1",
            update.seed_url
        )

        if not seed:
            raise HTTPException(
                status_code=404,
                detail=f"Seed nicht gefunden: {update.seed_url}"
            )

        # Update the seed with crawl status
        new_total = (seed["total_documents"] or 0) + update.documents_crawled

        await conn.execute("""
            UPDATE edu_search_seeds
            SET
                last_crawled_at = NOW(),
                last_crawl_status = $2,
                last_crawl_docs = $3,
                total_documents = $4,
                updated_at = NOW()
            WHERE id = $1
        """, seed["id"], update.status, update.documents_crawled, new_total)

        logger.info(
            f"Crawl status updated: {update.seed_url} - "
            f"status={update.status}, docs={update.documents_crawled}, "
            f"duration={update.crawl_duration_seconds:.1f}s"
        )

        return CrawlStatusResponse(
            success=True,
            seed_url=update.seed_url,
            message=f"Status aktualisiert: {update.documents_crawled} Dokumente gecrawlt"
        )


class BulkCrawlStatusUpdate(BaseModel):
    """Bulk crawl status update."""
    updates: List[CrawlStatusUpdate]


class BulkCrawlStatusResponse(BaseModel):
    """Response for bulk crawl status update."""
    updated: int
    failed: int
    errors: List[str]


@router.post("/seeds/crawl-status/bulk", response_model=BulkCrawlStatusResponse)
async def bulk_update_crawl_status(request: BulkCrawlStatusUpdate):
    """Bulk update crawl status for multiple seeds."""
    pool = await get_db_pool()
    updated = 0
    failed = 0
    errors = []

    async with pool.acquire() as conn:
        for update in request.updates:
            try:
                seed = await conn.fetchrow(
                    "SELECT id, total_documents FROM edu_search_seeds WHERE url = $1",
                    update.seed_url
                )

                if not seed:
                    failed += 1
                    errors.append(f"Seed nicht gefunden: {update.seed_url}")
                    continue

                new_total = (seed["total_documents"] or 0) + update.documents_crawled

                await conn.execute("""
                    UPDATE edu_search_seeds
                    SET
                        last_crawled_at = NOW(),
                        last_crawl_status = $2,
                        last_crawl_docs = $3,
                        total_documents = $4,
                        updated_at = NOW()
                    WHERE id = $1
                """, seed["id"], update.status, update.documents_crawled, new_total)

                updated += 1

            except Exception as e:
                failed += 1
                errors.append(f"{update.seed_url}: {str(e)}")

    logger.info(f"Bulk crawl status update: {updated} updated, {failed} failed")

    return BulkCrawlStatusResponse(
        updated=updated,
        failed=failed,
        errors=errors
    )