"""
Opportunities (Pipeline) Router
Hub-local sales pipeline
"""

from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel
from typing import Optional, List, Dict
from datetime import date, datetime
import json
import logging

from app.core.database import execute_query, execute_query_single, execute_update
from app.services.opportunity_service import handle_stage_change

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


class PipelineStageBase(BaseModel):
    name: str
    description: Optional[str] = None
    sort_order: int = 0
    default_probability: int = 0
    color: Optional[str] = "#0f4c75"
    is_won: bool = False
    is_lost: bool = False
    is_active: bool = True


class PipelineStageCreate(PipelineStageBase):
    pass


class PipelineStageUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None
    sort_order: Optional[int] = None
    default_probability: Optional[int] = None
    color: Optional[str] = None
    is_won: Optional[bool] = None
    is_lost: Optional[bool] = None
    is_active: Optional[bool] = None


class OpportunityBase(BaseModel):
    customer_id: int
    title: str
    description: Optional[str] = None
    amount: Optional[float] = 0
    currency: Optional[str] = "DKK"
    expected_close_date: Optional[date] = None
    stage_id: Optional[int] = None
    owner_user_id: Optional[int] = None


class OpportunityCreate(OpportunityBase):
    pass


class OpportunityUpdate(BaseModel):
    title: Optional[str] = None
    description: Optional[str] = None
    amount: Optional[float] = None
    currency: Optional[str] = None
    expected_close_date: Optional[date] = None
    stage_id: Optional[int] = None
    owner_user_id: Optional[int] = None
    is_active: Optional[bool] = None


class OpportunityStageUpdate(BaseModel):
    stage_id: int
    note: Optional[str] = None
    user_id: Optional[int] = None


class OpportunityLineBase(BaseModel):
    name: str
    quantity: int = 1
    unit_price: float = 0.0
    product_number: Optional[str] = None
    description: Optional[str] = None


class OpportunityLineCreate(OpportunityLineBase):
    pass


class OpportunityCommentBase(BaseModel):
    content: str
    author_name: Optional[str] = None
    user_id: Optional[int] = None
    email_id: Optional[int] = None
    contract_number: Optional[str] = None
    contract_context: Optional[str] = None
    contract_link: Optional[str] = None
    metadata: Optional[Dict] = None


class OpportunityCommentCreate(OpportunityCommentBase):
    pass


class OpportunityCommentResponse(BaseModel):
    id: int
    opportunity_id: int
    content: str
    author_name: Optional[str] = None
    user_id: Optional[int] = None
    user_full_name: Optional[str] = None
    username: Optional[str] = None
    email_id: Optional[int] = None
    email_subject: Optional[str] = None
    email_sender: Optional[str] = None
    contract_number: Optional[str] = None
    contract_context: Optional[str] = None
    contract_link: Optional[str] = None
    metadata: Optional[Dict] = None
    created_at: datetime
    updated_at: datetime


def _get_stage(stage_id: int):
    stage = execute_query_single(
        "SELECT * FROM pipeline_stages WHERE id = %s AND is_active = TRUE",
        (stage_id,)
    )
    if not stage:
        raise HTTPException(status_code=404, detail="Stage not found")
    return stage


def _get_default_stage():
    stage = execute_query_single(
        "SELECT * FROM pipeline_stages WHERE is_active = TRUE ORDER BY sort_order ASC LIMIT 1"
    )
    if not stage:
        raise HTTPException(status_code=400, detail="No active stages configured")
    return stage


def _get_opportunity(opportunity_id: int):
    query = """
        SELECT o.*, c.name AS customer_name,
               s.name AS stage_name, s.color AS stage_color, s.is_won, s.is_lost
        FROM pipeline_opportunities o
        JOIN customers c ON c.id = o.customer_id
        JOIN pipeline_stages s ON s.id = o.stage_id
        WHERE o.id = %s
    """
    opportunity = execute_query_single(query, (opportunity_id,))
    if not opportunity:
        raise HTTPException(status_code=404, detail="Opportunity not found")
    return opportunity


def _insert_stage_history(opportunity_id: int, from_stage_id: Optional[int], to_stage_id: int,
                          user_id: Optional[int] = None, note: Optional[str] = None):
    execute_query(
        """
        INSERT INTO pipeline_stage_history (opportunity_id, from_stage_id, to_stage_id, changed_by_user_id, note)
        VALUES (%s, %s, %s, %s, %s)
        """,
        (opportunity_id, from_stage_id, to_stage_id, user_id, note)
    )


def _fetch_opportunity_comments(opportunity_id: int):
    query = """
        SELECT c.*, u.full_name AS user_full_name, u.username,
               em.subject AS email_subject, em.sender_email AS email_sender
        FROM pipeline_opportunity_comments c
        LEFT JOIN users u ON u.user_id = c.user_id
        LEFT JOIN email_messages em ON em.id = c.email_id
        WHERE c.opportunity_id = %s
        ORDER BY c.created_at DESC
    """
    return execute_query(query, (opportunity_id,)) or []


def _fetch_comment(comment_id: int):
    query = """
        SELECT c.*, u.full_name AS user_full_name, u.username,
               em.subject AS email_subject, em.sender_email AS email_sender
        FROM pipeline_opportunity_comments c
        LEFT JOIN users u ON u.user_id = c.user_id
        LEFT JOIN email_messages em ON em.id = c.email_id
        WHERE c.id = %s
    """
    result = execute_query(query, (comment_id,))
    return result[0] if result else None


# ============================
# Pipeline Stages
# ============================

@router.get("/pipeline/stages", tags=["Pipeline Stages"])
async def list_stages():
    query = "SELECT * FROM pipeline_stages WHERE is_active = TRUE ORDER BY sort_order ASC"
    return execute_query(query) or []


@router.post("/pipeline/stages", tags=["Pipeline Stages"])
async def create_stage(stage: PipelineStageCreate):
    query = """
        INSERT INTO pipeline_stages
        (name, description, sort_order, default_probability, color, is_won, is_lost, is_active)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s)
        RETURNING *
    """
    result = execute_query(query, (
        stage.name,
        stage.description,
        stage.sort_order,
        stage.default_probability,
        stage.color,
        stage.is_won,
        stage.is_lost,
        stage.is_active
    ))
    logger.info("✅ Created pipeline stage: %s", stage.name)
    return result[0] if result else None


@router.put("/pipeline/stages/{stage_id}", tags=["Pipeline Stages"])
async def update_stage(stage_id: int, stage: PipelineStageUpdate):
    updates = []
    params = []
    for field, value in stage.dict(exclude_unset=True).items():
        updates.append(f"{field} = %s")
        params.append(value)

    if not updates:
        raise HTTPException(status_code=400, detail="No fields to update")

    params.append(stage_id)
    query = f"UPDATE pipeline_stages SET {', '.join(updates)}, updated_at = CURRENT_TIMESTAMP WHERE id = %s RETURNING *"
    result = execute_query(query, tuple(params))

    if not result:
        raise HTTPException(status_code=404, detail="Stage not found")

    logger.info("✅ Updated pipeline stage: %s", stage_id)
    return result[0]


@router.delete("/pipeline/stages/{stage_id}", tags=["Pipeline Stages"])
async def deactivate_stage(stage_id: int):
    affected = execute_update(
        "UPDATE pipeline_stages SET is_active = FALSE, updated_at = CURRENT_TIMESTAMP WHERE id = %s",
        (stage_id,)
    )
    if not affected:
        raise HTTPException(status_code=404, detail="Stage not found")
    logger.info("⚠️ Deactivated pipeline stage: %s", stage_id)
    return {"status": "success", "stage_id": stage_id}


# ============================
# Opportunities
# ============================

@router.get("/opportunities", tags=["Opportunities"])
async def list_opportunities(customer_id: Optional[int] = None, stage_id: Optional[int] = None):
    query = """
        SELECT o.*, c.name AS customer_name,
               s.name AS stage_name, s.color AS stage_color, s.is_won, s.is_lost
        FROM pipeline_opportunities o
        JOIN customers c ON c.id = o.customer_id
        JOIN pipeline_stages s ON s.id = o.stage_id
        WHERE o.is_active = TRUE
    """
    params: List = []
    if customer_id is not None:
        query += " AND o.customer_id = %s"
        params.append(customer_id)
    if stage_id is not None:
        query += " AND o.stage_id = %s"
        params.append(stage_id)

    query += " ORDER BY o.updated_at DESC NULLS LAST, o.created_at DESC"
    if params:
        return execute_query(query, tuple(params)) or []
    return execute_query(query) or []


@router.get("/opportunities/{opportunity_id}", tags=["Opportunities"])
async def get_opportunity(opportunity_id: int):
    return _get_opportunity(opportunity_id)


@router.post("/opportunities", tags=["Opportunities"])
async def create_opportunity(opportunity: OpportunityCreate):
    stage = _get_stage(opportunity.stage_id) if opportunity.stage_id else _get_default_stage()
    probability = stage["default_probability"]

    query = """
        INSERT INTO pipeline_opportunities
        (customer_id, title, description, amount, currency, expected_close_date, stage_id, probability, owner_user_id)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
        RETURNING id
    """
    result = execute_query(query, (
        opportunity.customer_id,
        opportunity.title,
        opportunity.description,
        opportunity.amount or 0,
        opportunity.currency or "DKK",
        opportunity.expected_close_date,
        stage["id"],
        probability,
        opportunity.owner_user_id
    ))

    if not result:
        raise HTTPException(status_code=500, detail="Failed to create opportunity")

    opportunity_id = result[0]["id"]
    _insert_stage_history(opportunity_id, None, stage["id"], opportunity.owner_user_id, "Oprettet")
    logger.info("✅ Created opportunity %s", opportunity_id)
    return _get_opportunity(opportunity_id)


@router.put("/opportunities/{opportunity_id}", tags=["Opportunities"])
async def update_opportunity(opportunity_id: int, update: OpportunityUpdate):
    existing = _get_opportunity(opportunity_id)
    updates = []
    params = []

    update_dict = update.dict(exclude_unset=True)
    stage_changed = False
    new_stage = None

    if "stage_id" in update_dict:
        new_stage = _get_stage(update_dict["stage_id"])
        update_dict["probability"] = new_stage["default_probability"]
        stage_changed = new_stage["id"] != existing["stage_id"]

    for field, value in update_dict.items():
        updates.append(f"{field} = %s")
        params.append(value)

    if not updates:
        raise HTTPException(status_code=400, detail="No fields to update")

    params.append(opportunity_id)
    query = f"UPDATE pipeline_opportunities SET {', '.join(updates)}, updated_at = CURRENT_TIMESTAMP WHERE id = %s"
    execute_update(query, tuple(params))

    if stage_changed and new_stage:
        _insert_stage_history(opportunity_id, existing["stage_id"], new_stage["id"], update.owner_user_id, "Stage ændret")
        updated = _get_opportunity(opportunity_id)
        handle_stage_change(updated, new_stage)

    return _get_opportunity(opportunity_id)


@router.patch("/opportunities/{opportunity_id}/stage", tags=["Opportunities"])
async def update_opportunity_stage(opportunity_id: int, update: OpportunityStageUpdate):
    existing = _get_opportunity(opportunity_id)
    new_stage = _get_stage(update.stage_id)

    execute_update(
        """
        UPDATE pipeline_opportunities
        SET stage_id = %s,
            probability = %s,
            updated_at = CURRENT_TIMESTAMP
        WHERE id = %s
        """,
        (new_stage["id"], new_stage["default_probability"], opportunity_id)
    )

    _insert_stage_history(opportunity_id, existing["stage_id"], new_stage["id"], update.user_id, update.note)
    updated = _get_opportunity(opportunity_id)
    handle_stage_change(updated, new_stage)

    return updated


@router.get("/opportunities/{opportunity_id}/lines", tags=["Opportunities"])
async def list_opportunity_lines(opportunity_id: int):
    query = """
        SELECT id, opportunity_id, product_number, name, description, quantity, unit_price,
               quantity * unit_price AS total_price
        FROM pipeline_opportunity_lines
        WHERE opportunity_id = %s
        ORDER BY id ASC
    """
    return execute_query(query, (opportunity_id,)) or []


@router.post("/opportunities/{opportunity_id}/lines", tags=["Opportunities"])
async def add_opportunity_line(opportunity_id: int, line: OpportunityLineCreate):
    query = """
        INSERT INTO pipeline_opportunity_lines
        (opportunity_id, product_number, name, description, quantity, unit_price)
        VALUES (%s, %s, %s, %s, %s, %s)
        RETURNING id, opportunity_id, product_number, name, description, quantity, unit_price,
                  quantity * unit_price AS total_price
    """
    result = execute_query(
        query,
        (
            opportunity_id,
            line.product_number,
            line.name,
            line.description,
            line.quantity,
            line.unit_price
        )
    )
    if not result:
        raise HTTPException(status_code=500, detail="Failed to create line item")
    return result[0]


@router.delete("/opportunities/{opportunity_id}/lines/{line_id}", tags=["Opportunities"])
async def remove_opportunity_line(opportunity_id: int, line_id: int):
    query = """
        DELETE FROM pipeline_opportunity_lines
        WHERE opportunity_id = %s AND id = %s
        RETURNING id
    """
    result = execute_query(query, (opportunity_id, line_id))
    if not result:
        raise HTTPException(status_code=404, detail="Line item not found")
    return {"success": True, "line_id": line_id}


@router.get(
    "/opportunities/{opportunity_id}/comments",
    response_model=List[OpportunityCommentResponse],
    tags=["Opportunities"]
)
async def list_opportunity_comments(opportunity_id: int):
    _get_opportunity(opportunity_id)
    return _fetch_opportunity_comments(opportunity_id)


@router.post(
    "/opportunities/{opportunity_id}/comments",
    response_model=OpportunityCommentResponse,
    tags=["Opportunities"]
)
async def add_opportunity_comment(opportunity_id: int, comment: OpportunityCommentCreate):
    _get_opportunity(opportunity_id)

    author_name = comment.author_name or 'Hub Bruger'
    metadata_json = json.dumps(comment.metadata) if comment.metadata else None

    query = """
        INSERT INTO pipeline_opportunity_comments
            (opportunity_id, user_id, author_name, content, email_id,
             contract_number, contract_context, contract_link, metadata)
        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
        RETURNING id
    """

    result = execute_query(
        query,
        (
            opportunity_id,
            comment.user_id,
            author_name,
            comment.content,
            comment.email_id,
            comment.contract_number,
            comment.contract_context,
            comment.contract_link,
            metadata_json
        )
    )

    if not result:
        raise HTTPException(status_code=500, detail="Kunne ikke oprette kommentar")

    comment_id = result[0]["id"]
    return _fetch_comment(comment_id)


@router.get(
    "/contracts/search",
    tags=["Opportunities"],
    response_model=List[Dict]
)
async def search_contracts(query: str = Query(..., min_length=2), limit: int = Query(10, ge=1, le=50)):
    sql = """
        SELECT contract_number,
               MAX(created_at) AS last_seen,
               COUNT(*) AS hits
        FROM extraction_lines
        WHERE contract_number IS NOT NULL
          AND contract_number <> ''
          AND contract_number ILIKE %s
        GROUP BY contract_number
        ORDER BY MAX(created_at) DESC
        LIMIT %s
    """
    params = (f"%{query}%", limit)
    results = execute_query(sql, params)
    return results or []