import time
import jwt
import httpx

class GhostClient:
    def __init__(self, admin_url: str, api_key: str, version: str = "v5.0"):
        self.admin_url = admin_url.rstrip("/")
        self.api_key = api_key
        self.version = version
    
    def _make_token(self):
        key_id, secret = self.api_key.split(":", 1)
        now = int(time.time())
        payload = {
            "iat": now,
            "exp": now + 5 * 60,  # 5 minute expiry
            "aud": "/admin/",
        }
        header = {"alg": "HS256", "kid": key_id, "typ": "JWT"}
        secret_bytes = bytes.fromhex(secret)
        return jwt.encode(payload, secret_bytes, algorithm="HS256", headers=header)
    
    def _headers(self):
        return {
            "Authorization": f"Ghost {self._make_token()}",
            "Accept-Version": self.version,
            "Content-Type": "application/json",
        }
    
    def _base(self):
        return f"{self.admin_url}/ghost/api/admin"
    
    async def list_articles(self, limit: int = 20):
        url = f"{self._base()}/posts/"
        params = {
            "limit": limit,
            "fields": "id,title,slug,excerpt,html,created_at,updated_at,status,url",
        }
        async with httpx.AsyncClient(timeout=15) as client:
            resp = await client.get(url, headers=self._headers(), params=params)
            resp.raise_for_status()
        return resp.json().get("posts", [])
    
    async def update_article(self, article_id: str, updates: dict):
        # Get current post for updated_at
        get_url = f"{self._base()}/posts/{article_id}/"
        async with httpx.AsyncClient(timeout=15) as client:
            current = await client.get(get_url, headers=self._headers())
            current.raise_for_status()
        current_post = current.json()["posts"][0]
        
        payload_post = {
            "id": article_id,
            "updated_at": current_post["updated_at"],  # Required for collision detection
        }
        
        if "title" in updates:
            payload_post["title"] = updates["title"]
        if "content" in updates:
            payload_post["html"] = updates["content"]
        if "excerpt" in updates:
            payload_post["excerpt"] = updates["excerpt"]
        if "status" in updates:
            payload_post["status"] = updates["status"]
        
        async with httpx.AsyncClient(timeout=15) as client:
            resp = await client.put(
                get_url,
                headers=self._headers(),
                json={"posts": [payload_post]}
            )
            resp.raise_for_status()
        return resp.json()["posts"][0]