"""Content generation router.

Handles post generation via LLM, image generation, and CRUD operations on posts.
"""

from datetime import date, datetime

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session

from ..auth import get_current_user
from ..database import get_db
from ..models import AffiliateLink, Character, Post, SystemSetting, User
from ..plan_limits import check_limit
from ..schemas import (
    GenerateContentRequest,
    GenerateImageRequest,
    PostResponse,
    PostUpdate,
)
from ..services.content import generate_hashtags, generate_post_text, inject_affiliate_links
from ..services.images import get_image_provider
from ..services.llm import get_llm_provider

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


def _get_setting(db: Session, key: str, user_id: int = None) -> str | None:
    """Retrieve a system setting value by key, preferring user-specific over global."""
    if user_id is not None:
        setting = (
            db.query(SystemSetting)
            .filter(SystemSetting.key == key, SystemSetting.user_id == user_id)
            .first()
        )
        if setting is not None:
            return setting.value
    # Fallback to global (no user_id)
    setting = db.query(SystemSetting).filter(SystemSetting.key == key, SystemSetting.user_id == None).first()
    if setting is None:
        return None
    return setting.value


@router.post("/generate", response_model=PostResponse)
def generate_content(
    request: GenerateContentRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Generate content for a character using LLM."""
    # Validate character belongs to user
    character = (
        db.query(Character)
        .filter(Character.id == request.character_id, Character.user_id == current_user.id)
        .first()
    )
    if not character:
        raise HTTPException(status_code=404, detail="Character not found")

    # Check monthly post limit
    first_of_month = date.today().replace(day=1)
    if current_user.posts_reset_date != first_of_month:
        current_user.posts_generated_this_month = 0
        current_user.posts_reset_date = first_of_month
        db.commit()

    allowed, msg = check_limit(current_user, "posts_per_month", current_user.posts_generated_this_month or 0)
    if not allowed:
        raise HTTPException(status_code=403, detail={"message": msg, "upgrade_required": True})

    # Get LLM settings (user-specific first, then global)
    provider_name = request.provider or _get_setting(db, "llm_provider", current_user.id)
    api_key = _get_setting(db, "llm_api_key", current_user.id)
    model = request.model or _get_setting(db, "llm_model", current_user.id)

    if not provider_name:
        raise HTTPException(status_code=400, detail="LLM provider not configured. Set 'llm_provider' in settings.")
    if not api_key:
        raise HTTPException(status_code=400, detail="LLM API key not configured. Set 'llm_api_key' in settings.")

    # Build character dict for content service
    char_dict = {
        "name": character.name,
        "niche": character.niche,
        "topics": character.topics or [],
        "tone": character.tone or "professional",
    }

    # Create LLM provider and generate text
    base_url = _get_setting(db, "llm_base_url", current_user.id)
    llm = get_llm_provider(provider_name, api_key, model, base_url=base_url)
    text = generate_post_text(
        character=char_dict,
        llm_provider=llm,
        platform=request.effective_platform,
        topic_hint=request.topic_hint,
    )

    # Generate hashtags
    hashtags = generate_hashtags(text, llm, request.effective_platform)

    # Handle affiliate links
    affiliate_links_used: list[dict] = []
    if request.include_affiliates:
        links = (
            db.query(AffiliateLink)
            .filter(
                AffiliateLink.is_active == True,
                AffiliateLink.user_id == current_user.id,
                (AffiliateLink.character_id == character.id) | (AffiliateLink.character_id == None),
            )
            .all()
        )
        if links:
            link_dicts = [
                {
                    "url": link.url,
                    "label": link.name,
                    "keywords": link.topics or [],
                }
                for link in links
            ]
            text, affiliate_links_used = inject_affiliate_links(
                text, link_dicts, character.topics or []
            )

    # Create post record
    post = Post(
        character_id=character.id,
        user_id=current_user.id,
        content_type=request.content_type,
        text_content=text,
        hashtags=hashtags,
        affiliate_links_used=affiliate_links_used,
        llm_provider=provider_name,
        llm_model=model,
        platform_hint=request.platform,
        status="draft",
    )
    db.add(post)

    # Increment monthly counter
    current_user.posts_generated_this_month = (current_user.posts_generated_this_month or 0) + 1
    db.commit()
    db.refresh(post)
    return post


@router.post("/generate-image", response_model=PostResponse)
def generate_image(
    request: GenerateImageRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Generate an image for a character and attach to a post."""
    character = (
        db.query(Character)
        .filter(Character.id == request.character_id, Character.user_id == current_user.id)
        .first()
    )
    if not character:
        raise HTTPException(status_code=404, detail="Character not found")

    provider_name = request.provider or _get_setting(db, "image_provider", current_user.id)
    api_key = _get_setting(db, "image_api_key", current_user.id)

    if not provider_name:
        raise HTTPException(status_code=400, detail="Image provider not configured. Set 'image_provider' in settings.")
    if not api_key:
        raise HTTPException(status_code=400, detail="Image API key not configured. Set 'image_api_key' in settings.")

    prompt = request.prompt
    if not prompt:
        style_hint = request.style_hint or ""
        visual_style = character.visual_style or {}
        style_desc = visual_style.get("description", "")
        prompt = (
            f"Create a social media image for {character.name}, "
            f"a content creator in the {character.niche} niche. "
            f"Style: {style_desc} {style_hint}".strip()
        )

    image_provider = get_image_provider(provider_name, api_key)
    image_url = image_provider.generate(prompt, size=request.size)

    post = Post(
        character_id=character.id,
        user_id=current_user.id,
        content_type="image",
        image_url=image_url,
        platform_hint="instagram",
        status="draft",
    )
    db.add(post)
    db.commit()
    db.refresh(post)
    return post


@router.get("/posts", response_model=list[PostResponse])
def list_posts(
    character_id: int | None = Query(None),
    status: str | None = Query(None),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """List all posts with optional filters."""
    query = db.query(Post).filter(Post.user_id == current_user.id)
    if character_id is not None:
        query = query.filter(Post.character_id == character_id)
    if status is not None:
        query = query.filter(Post.status == status)
    return query.order_by(Post.created_at.desc()).all()


@router.get("/posts/{post_id}", response_model=PostResponse)
def get_post(
    post_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Get a single post by ID."""
    post = db.query(Post).filter(Post.id == post_id, Post.user_id == current_user.id).first()
    if not post:
        raise HTTPException(status_code=404, detail="Post not found")
    return post


@router.put("/posts/{post_id}", response_model=PostResponse)
def update_post(
    post_id: int,
    data: PostUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Update a post."""
    post = db.query(Post).filter(Post.id == post_id, Post.user_id == current_user.id).first()
    if not post:
        raise HTTPException(status_code=404, detail="Post not found")
    update_data = data.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(post, key, value)
    post.updated_at = datetime.utcnow()
    db.commit()
    db.refresh(post)
    return post


@router.delete("/posts/{post_id}", status_code=204)
def delete_post(
    post_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Delete a post."""
    post = db.query(Post).filter(Post.id == post_id, Post.user_id == current_user.id).first()
    if not post:
        raise HTTPException(status_code=404, detail="Post not found")
    db.delete(post)
    db.commit()


@router.post("/posts/{post_id}/approve", response_model=PostResponse)
def approve_post(
    post_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Approve a post (set status to 'approved')."""
    post = db.query(Post).filter(Post.id == post_id, Post.user_id == current_user.id).first()
    if not post:
        raise HTTPException(status_code=404, detail="Post not found")
    post.status = "approved"
    post.updated_at = datetime.utcnow()
    db.commit()
    db.refresh(post)
    return post