# ============================================================
# File: scraper/utils/state_sync.py
# Purpose:
#    State inspection + optional sync logic for book progress.
#    This version provides:
#      • inspect_books_state()  → NO writes, just a dry-run
#      • sync_books_from_redis() → NOT USED YET (kept commented)
# ============================================================

import os
import redis
from db.db import get_db


def inspect_books_state():
    """
    Reads all books from SQLite and fetches Redis progress,
    but performs NO writes. Only shows:
        - sqlite row
        - redis state
        - merged result (dry-run)

    Returns a list of inspection dicts.
    """
    r = redis.Redis.from_url(os.getenv("REDIS_BROKER"))
    db = get_db()
    cur = db.cursor()

    cur.execute("SELECT * FROM books")
    rows = cur.fetchall()

    results = []

    for row in rows:
        book_id = row["book_id"]
        sqlite_row = dict(row)

        # Read redis state
        redis_key = f"book:{book_id}:state"
        progress = r.hgetall(redis_key)

        if progress:
            decoded = {k.decode(): v.decode() for k, v in progress.items()}
        else:
            decoded = {}

        # Determine dry-run merged result
        merged = sqlite_row.copy()

        if decoded:
            merged["downloaded"] = int(
                decoded.get("download_done", merged.get("downloaded", 0))
            )
            merged["parsed"] = int(decoded.get("parsed_done", merged.get("parsed", 0)))
            merged["audio_done"] = int(
                decoded.get("audio_done", merged.get("audio_done", 0))
            )
            merged["chapters_total"] = int(
                decoded.get("chapters_total", merged.get("chapters_total", 0))
            )
            merged["status"] = decoded.get("status", merged.get("status", "unknown"))

        results.append(
            {
                "book_id": book_id,
                "sqlite": sqlite_row,
                "redis": decoded,
                "would_merge_to": merged,
            }
        )

    return results


def sync_books_from_redis():
    """
    Reads all books from SQLite, fetches Redis progress,
    and updates SQLite rows accordingly.

    Returns a list of {
        "book_id": ...,
        "before": ...,
        "redis": ...,
        "after": ...
    }
    """
    r = redis.Redis.from_url(os.getenv("REDIS_BROKER"))
    db = get_db()
    cur = db.cursor()

    # Haal alle boeken op
    cur.execute("SELECT * FROM books")
    rows = cur.fetchall()

    results = []

    for row in rows:
        book_id = row["book_id"]
        before = dict(row)

        redis_key = f"book:{book_id}:state"
        progress = r.hgetall(redis_key)

        if not progress:
            results.append(
                {"book_id": book_id, "before": before, "redis": {}, "after": before}
            )
            continue

        # Decode Redis bytes → string dictionary
        decoded = {k.decode(): v.decode() for k, v in progress.items()}

        # Extract counters
        downloaded = int(decoded.get("download_done", 0))
        parsed = int(decoded.get("parsed_done", 0))
        audio_done = int(decoded.get("audio_done", 0))
        chapters_total = int(decoded.get("chapters_total", 0))

        # Redis status wins
        status = decoded.get("status", before["status"])

        # Write back to SQLite
        cur.execute(
            """
            UPDATE books
            SET downloaded = ?, parsed = ?, audio_done = ?, chapters_total = ?, status = ?, last_update = datetime('now')
            WHERE book_id = ?
            """,
            (downloaded, parsed, audio_done, chapters_total, status, book_id),
        )
        db.commit()

        # Fetch updated row
        cur.execute("SELECT * FROM books WHERE book_id = ?", (book_id,))
        after = dict(cur.fetchone())

        results.append(
            {"book_id": book_id, "before": before, "redis": decoded, "after": after}
        )

    return results