import os
import json
import requests
import time
from pathlib import Path
from dotenv import load_dotenv

env_path = Path(__file__).resolve().parent.parent / ".env"
load_dotenv(dotenv_path=env_path)

CLIENT_ID = os.getenv("LINKEDIN_CLIENT_ID", "")
CLIENT_SECRET = os.getenv("LINKEDIN_CLIENT_SECRET", "")
REDIRECT_URI = os.getenv("LINKEDIN_REDIRECT_URI", "http://localhost:8000/linkedin/callback/")
SCOPE = "w_member_social profile email openid"
API_BASE = "https://api.linkedin.com"
AUTH_BASE = "https://www.linkedin.com/oauth/v2"


def _log(msg):
    print(f"[LinkedInAPI] {msg}")


def get_oauth_url(state=""):
    params = {
        "response_type": "code",
        "client_id": CLIENT_ID,
        "redirect_uri": REDIRECT_URI,
        "scope": SCOPE,
    }
    if state:
        params["state"] = state
    qs = "&".join(f"{k}={requests.utils.quote(str(v))}" for k, v in params.items())
    return f"{AUTH_BASE}/authorization?{qs}"


def exchange_code(code):
    if not CLIENT_ID or not CLIENT_SECRET:
        return None, "LinkedIn app not configured. Set LINKEDIN_CLIENT_ID and LINKEDIN_CLIENT_SECRET."

    data = {
        "grant_type": "authorization_code",
        "code": code,
        "client_id": CLIENT_ID,
        "client_secret": CLIENT_SECRET,
        "redirect_uri": REDIRECT_URI,
    }
    try:
        resp = requests.post(f"{AUTH_BASE}/accessToken", data=data, timeout=30)
        if resp.status_code != 200:
            _log(f"Token exchange failed ({resp.status_code}): {resp.text[:200]}")
            return None, f"Failed to get access token: {resp.text[:100]}"
        body = resp.json()
        token = body.get("access_token")
        expires = body.get("expires_in", 86400)
        if not token:
            return None, "No access_token in response"
        _log("Token exchange successful")
        return {"access_token": token, "expires_at": time.time() + expires}, None
    except requests.exceptions.RequestException as e:
        _log(f"Token exchange error: {e}")
        return None, str(e)


def get_user_info(access_token):
    headers = {"Authorization": f"Bearer {access_token}"}
    try:
        resp = requests.get(f"{API_BASE}/v2/userinfo", headers=headers, timeout=15)
        if resp.status_code != 200:
            _log(f"User info failed ({resp.status_code}): {resp.text[:200]}")
            return None, "Failed to get user info"
        body = resp.json()
        sub = body.get("sub", "")
        name = body.get("name", "")
        picture = body.get("picture", "")
        _log(f"User info: {name} ({sub})")
        return {"urn": f"urn:li:person:{sub}", "name": name, "picture": picture, "sub": sub}, None
    except requests.exceptions.RequestException as e:
        _log(f"User info error: {e}")
        return None, str(e)


def create_post(access_token, author_urn, text, hashtags=None, visibility="PUBLIC"):
    if not access_token or not author_urn:
        return None, "Missing access_token or author_urn"

    body = {"author": author_urn, "lifecycleState": "PUBLISHED", "visibility": visibility}

    full_text = text
    if hashtags:
        tag_str = " ".join(f"#{h.lstrip('#')}" for h in hashtags[:5])
        full_text = f"{text}\n\n{tag_str}"

    body["specificContent"] = {
        "com.linkedin.ugc.ShareContent": {
            "shareCommentary": {"text": full_text},
            "shareMediaCategory": "NONE",
        }
    }

    headers = {
        "Authorization": f"Bearer {access_token}",
        "Content-Type": "application/json",
        "X-Restli-Protocol-Version": "2.0.0",
    }

    try:
        resp = requests.post(f"{API_BASE}/v2/ugcPosts", json=body, headers=headers, timeout=30)
        if resp.status_code in (200, 201):
            post_id = resp.headers.get("X-RestLi-Id", "")
            post_url = f"https://www.linkedin.com/feed/update/{post_id}" if post_id else ""
            _log(f"Post created: {post_id}")
            return {"post_id": post_id, "post_url": post_url}, None

        _log(f"Post failed ({resp.status_code}): {resp.text[:300]}")

        if resp.status_code == 401:
            return None, "Access token expired. Please reconnect LinkedIn."
        if resp.status_code == 403:
            return None, "Missing permissions. Re-authenticate with w_member_social scope."
        if resp.status_code == 429:
            return None, "Rate limited. Try again later."

        detail = ""
        try:
            detail = resp.json().get("message", resp.text[:100])
        except Exception:
            detail = resp.text[:100]
        return None, f"LinkedIn API error: {detail}"

    except requests.exceptions.RequestException as e:
        _log(f"Post request error: {e}")
        return None, str(e)