import os
import sqlite3
import zipfile
import io
import logging
from functools import wraps
from datetime import datetime
from flask import (
    Flask, g, render_template, request, redirect, url_for, abort,
    current_app, jsonify, send_file
)
import markdown2
from hmac import compare_digest as safe_str_cmp
from base64 import b64decode

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("textbooru")

BASE_DIR = os.path.dirname(__file__)
DB_PATH = os.path.join(BASE_DIR, "data.db")

# Basic auth credentials (set in .env or env vars)
ADMIN_USER = os.environ.get("ADMIN_USER", "admin")
ADMIN_PASS = os.environ.get("ADMIN_PASS", "password")  # change this in production

app = Flask(__name__)
app.config['SECRET_KEY'] = os.environ.get("SECRET_KEY", "change-me")

# --- DB utils ----------------------------------------------------------------
def get_db():
    db = getattr(g, "_database", None)
    if db is None:
        need_init = not os.path.exists(DB_PATH)
        db = g._database = sqlite3.connect(DB_PATH, check_same_thread=False)
        db.row_factory = sqlite3.Row
        if need_init:
            init_db(db)
    return db

def init_db(db):
    cur = db.cursor()
    cur.executescript("""
    CREATE TABLE IF NOT EXISTS posts (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      title TEXT,
      body TEXT,
      created_at TEXT
    );
    CREATE VIRTUAL TABLE IF NOT EXISTS posts_fts USING fts5(title, body, content='posts', content_rowid='id');
    CREATE TABLE IF NOT EXISTS tags (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT UNIQUE);
    CREATE TABLE IF NOT EXISTS post_tags (post_id INTEGER, tag_id INTEGER);
    CREATE TABLE IF NOT EXISTS votes (id INTEGER PRIMARY KEY AUTOINCREMENT, post_id INTEGER, voter_ip TEXT, vote INTEGER, created_at TEXT);
    CREATE TABLE IF NOT EXISTS flags (id INTEGER PRIMARY KEY AUTOINCREMENT, post_id INTEGER, reason TEXT, created_at TEXT, resolved INTEGER DEFAULT 0);
    """)
    db.commit()
    logger.info("Initialized DB at %s", DB_PATH)

@app.teardown_appcontext
def close_conn(exc):
    db = getattr(g, "_database", None)
    if db is not None:
        db.close()

# --- Helpers ----------------------------------------------------------------
def require_basic_auth(fn):
    @wraps(fn)
    def wrapper(*args, **kwargs):
        auth = request.headers.get("Authorization")
        if not auth or not auth.lower().startswith("basic "):
            return _basic_auth_required()
        try:
            payload = b64decode(auth.split(" ", 1)[1]).decode("utf-8")
            user, passwd = payload.split(":", 1)
        except Exception:
            return _basic_auth_required()
        if not (safe_str_cmp(user, ADMIN_USER) and safe_str_cmp(passwd, ADMIN_PASS)):
            return _basic_auth_required()
        return fn(*args, **kwargs)
    return wrapper

def _basic_auth_required():
    resp = current_app.make_response("Authentication required")
    resp.headers['WWW-Authenticate'] = 'Basic realm="TextBooru admin"'
    resp.status_code = 401
    return resp

def add_post(title, body, tags):
    db = get_db()
    cur = db.cursor()
    created = datetime.utcnow().isoformat()
    cur.execute("INSERT INTO posts (title, body, created_at) VALUES (?, ?, ?)", (title, body, created))
    post_id = cur.lastrowid
    try:
        cur.execute("INSERT INTO posts_fts (rowid, title, body) VALUES (?, ?, ?)", (post_id, title, body))
    except Exception:
        logger.exception("FTS insert failed")
    for t in tags:
        name = t.strip().lower()
        if not name:
            continue
        cur.execute("INSERT OR IGNORE INTO tags (name) VALUES (?)", (name,))
        cur.execute("SELECT id FROM tags WHERE name = ?", (name,))
        row = cur.fetchone()
        if row:
            tag_id = row["id"]
            cur.execute("INSERT OR IGNORE INTO post_tags (post_id, tag_id) VALUES (?, ?)", (post_id, tag_id))
    db.commit()
    return post_id

def get_tags_for_post(post_id):
    db = get_db()
    cur = db.cursor()
    cur.execute("""
      SELECT t.name FROM tags t
      JOIN post_tags pt ON pt.tag_id = t.id
      WHERE pt.post_id = ?
      ORDER BY t.name
    """, (post_id,))
    return [r["name"] for r in cur.fetchall()]

def get_vote_counts(post_id):
    db = get_db()
    cur = db.cursor()
    cur.execute("SELECT SUM(vote) as score, SUM(CASE WHEN vote>0 THEN 1 ELSE 0 END) as ups, SUM(CASE WHEN vote<0 THEN 1 ELSE 0 END) as downs FROM votes WHERE post_id = ?", (post_id,))
    row = cur.fetchone()
    if not row:
        return {"score":0,"ups":0,"downs":0}
    return {"score": row["score"] or 0, "ups": row["ups"] or 0, "downs": abs(row["downs"] or 0)}

# --- Routes -----------------------------------------------------------------
@app.context_processor
def inject_tags():
    db = get_db()
    cur = db.cursor()
    try:
        cur.execute("SELECT t.name, count(*) as cnt FROM tags t JOIN post_tags pt ON pt.tag_id = t.id GROUP BY t.id ORDER BY cnt DESC LIMIT 50")
        tags = cur.fetchall()
    except Exception:
        tags = []
    return dict(all_tags=tags)

@app.route("/")
def index():
    page = max(1, int(request.args.get("page", 1)))
    per_page = 20
    offset = (page - 1) * per_page
    db = get_db()
    cur = db.cursor()
    cur.execute("SELECT count(*) as c FROM posts")
    total = cur.fetchone()["c"] or 0
    cur.execute("SELECT id, title, body, created_at FROM posts ORDER BY id DESC LIMIT ? OFFSET ?", (per_page, offset))
    posts = cur.fetchall()
    pages = (total + per_page - 1) // per_page
    return render_template("index.html", posts=posts, get_tags=get_tags_for_post, markdown=markdown2.markdown, page=page, pages=pages)

@app.route("/post/<int:pid>")
def view_post(pid):
    db = get_db()
    cur = db.cursor()
    cur.execute("SELECT * FROM posts WHERE id = ?", (pid,))
    post = cur.fetchone()
    if not post:
        abort(404)
    tags = get_tags_for_post(pid)
    votes = get_vote_counts(pid)
    # fetch flags count
    cur.execute("SELECT count(*) as c FROM flags WHERE post_id = ? AND resolved = 0", (pid,))
    flags = cur.fetchone()["c"] or 0
    return render_template("post.html", post=post, tags=tags, votes=votes, flags=flags, markdown=markdown2.markdown)

@app.route("/add", methods=["GET", "POST"])
def add_route():
    if request.method == "POST":
        title = request.form.get("title","").strip()
        body = request.form.get("body","").strip()
        tags = [t for t in (request.form.get("tags","").split(",") if request.form.get("tags") else [])]
        if not body:
            return "Body required", 400
        pid = add_post(title, body, tags)
        return redirect(url_for("view_post", pid=pid))
    return render_template("add.html")

@app.route("/tag/<name>")
def tag_page(name):
    db = get_db()
    cur = db.cursor()
    cur.execute("""
      SELECT p.id,p.title,p.body,p.created_at FROM posts p
      JOIN post_tags pt ON pt.post_id = p.id
      JOIN tags t ON t.id = pt.tag_id
      WHERE t.name = ?
      ORDER BY p.id DESC
      LIMIT 100
    """, (name.lower(),))
    posts = cur.fetchall()
    return render_template("index.html", posts=posts, get_tags=get_tags_for_post, current_tag=name, markdown=markdown2.markdown)

@app.route("/search")
def search():
    q = request.args.get("q","").strip()
    results = []
    if q:
        db = get_db()
        cur = db.cursor()
        try:
            cur.execute("SELECT rowid FROM posts_fts WHERE posts_fts MATCH ? LIMIT 200", (q,))
            rows = cur.fetchall()
            ids = [r["rowid"] for r in rows]
        except Exception:
            logger.warning("FTS failed, falling back to LIKE")
            cur.execute("SELECT id FROM posts WHERE title LIKE ? OR body LIKE ? LIMIT 200", (f"%{q}%", f"%{q}%"))
            rows = cur.fetchall()
            ids = [r["id"] for r in rows]
        if ids:
            placeholders = ",".join(["?"]*len(ids))
            cur.execute(f"SELECT id,title,body,created_at FROM posts WHERE id IN ({placeholders}) ORDER BY id DESC", ids)
            results = cur.fetchall()
    return render_template("search.html", q=q, posts=results, get_tags=get_tags_for_post, markdown=markdown2.markdown)

# --- Voting endpoints -------------------------------------------------------
@app.route("/vote/<int:pid>", methods=["POST"])
def vote(pid):
    # vote value: 'up' or 'down'
    v = request.form.get("vote")
    vote_value = 1 if v == "up" else -1
    voter_ip = request.remote_addr or "anon"
    db = get_db()
    cur = db.cursor()
    # prevent multiple same votes from same ip (simple prototype)
    cur.execute("SELECT id, vote FROM votes WHERE post_id = ? AND voter_ip = ?", (pid, voter_ip))
    row = cur.fetchone()
    if row:
        # if same vote, remove (toggle), if opposite, update
        if row["vote"] == vote_value:
            cur.execute("DELETE FROM votes WHERE id = ?", (row["id"],))
        else:
            cur.execute("UPDATE votes SET vote = ?, created_at = ? WHERE id = ?", (vote_value, datetime.utcnow().isoformat(), row["id"]))
    else:
        cur.execute("INSERT INTO votes (post_id, voter_ip, vote, created_at) VALUES (?, ?, ?, ?)", (pid, voter_ip, vote_value, datetime.utcnow().isoformat()))
    db.commit()
    return redirect(url_for("view_post", pid=pid))

# --- Tag autocomplete -------------------------------------------------------
@app.route("/_tags")
def tag_suggest():
    q = request.args.get("q","").strip().lower()
    db = get_db()
    cur = db.cursor()
    if not q:
        cur.execute("SELECT name FROM tags ORDER BY name LIMIT 50")
        rows = cur.fetchall()
    else:
        cur.execute("SELECT name FROM tags WHERE name LIKE ? ORDER BY name LIMIT 25", (f"{q}%",))
        rows = cur.fetchall()
    return jsonify([r["name"] for r in rows])

# --- Flags / moderation ----------------------------------------------------
@app.route("/flag/<int:pid>", methods=["POST"])
def flag_post(pid):
    reason = request.form.get("reason","").strip()
    if not reason:
        reason = "no reason"
    db = get_db()
    cur = db.cursor()
    cur.execute("INSERT INTO flags (post_id, reason, created_at, resolved) VALUES (?, ?, ?, 0)", (pid, reason, datetime.utcnow().isoformat()))
    db.commit()
    return redirect(url_for("view_post", pid=pid))

@app.route("/mod")
@require_basic_auth
def mod_index():
    db = get_db()
    cur = db.cursor()
    cur.execute("SELECT f.id,f.post_id,f.reason,f.created_at,f.resolved,p.title FROM flags f LEFT JOIN posts p ON p.id = f.post_id ORDER BY f.created_at DESC LIMIT 200")
    flags = cur.fetchall()
    return render_template("mod.html", flags=flags)

@app.route("/mod/resolve/<int:fid>", methods=["POST"])
@require_basic_auth
def mod_resolve(fid):
    db = get_db()
    cur = db.cursor()
    cur.execute("UPDATE flags SET resolved = 1 WHERE id = ?", (fid,))
    db.commit()
    return redirect(url_for("mod_index"))

# --- Bulk import (ZIP of .txt/.md) -----------------------------------------
@app.route("/api/import", methods=["POST"])
@require_basic_auth
def api_import():
    """
    Accepts multipart/form-data with file field 'file' containing a ZIP archive.
    Each .txt/.md file becomes a post. First non-empty line becomes title if short.
    Optional query param 'tags' (comma separated) to assign default tags.
    """
    if 'file' not in request.files:
        return jsonify({"error":"file required (zip)"}), 400
    f = request.files['file']
    tags_param = request.form.get("tags","")
    default_tags = [t.strip() for t in tags_param.split(",") if t.strip()]
    try:
        data = f.read()
        z = zipfile.ZipFile(io.BytesIO(data))
    except Exception as e:
        return jsonify({"error":"invalid zip", "detail": str(e)}), 400
    imported = []
    for name in z.namelist():
        if name.endswith("/") or name.startswith("__MACOSX"):
            continue
        if not (name.lower().endswith(".txt") or name.lower().endswith(".md")):
            continue
        try:
            content = z.read(name).decode("utf-8", errors="replace").strip()
            if not content:
                continue
            # heuristics: first non-empty line <= 80 chars -> title
            title = ""
            body = content
            for line in content.splitlines():
                if line.strip():
                    if len(line.strip()) <= 120:
                        title = line.strip()
                        # body remove first occurrence of that line
                        body = content.replace(line, "", 1).lstrip("\n")
                    break
            pid = add_post(title, body, default_tags)
            imported.append({"file":name, "post_id": pid})
        except Exception as e:
            logger.exception("Import error for %s", name)
    return jsonify({"imported": imported, "count": len(imported)})

# --- Export helper: export posts as zip of md (optional) --------------------
@app.route("/api/export/zip")
@require_basic_auth
def api_export_zip():
    db = get_db()
    cur = db.cursor()
    cur.execute("SELECT id,title,body,created_at FROM posts ORDER BY id")
    rows = cur.fetchall()
    mem = io.BytesIO()
    with zipfile.ZipFile(mem, "w") as z:
        for r in rows:
            fname = f"post_{r['id']}.md"
            content = (f"# {r['title']}\n\n" if r['title'] else "") + r['body']
            z.writestr(fname, content)
    mem.seek(0)
    return send_file(mem, mimetype="application/zip", download_name="export_posts.zip", as_attachment=True)

# --- Simple health / info --------------------------------------------------
@app.route("/status")
def status():
    return jsonify({"status":"ok"})

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080)