"""
setup_db.py
-----------
Run once to create all MongoDB collections, validators, and indexes
for the FactCheck AI project on Atlas.

Usage:
    python setup_db.py
"""

import os
import sys
from dotenv import load_dotenv
from pymongo import MongoClient, ASCENDING, DESCENDING
from pymongo.errors import CollectionInvalid

load_dotenv()

MONGO_URI    = os.getenv("MONGO_URI")
MONGO_DB     = os.getenv("MONGO_DB_NAME", "factcheck")

if not MONGO_URI:
    sys.exit("[ERROR] MONGO_URI not found in .env")

print(f"[DB] Connecting to Atlas … db={MONGO_DB}")
client = MongoClient(MONGO_URI, serverSelectionTimeoutMS=8000)
db     = client[MONGO_DB]

# ── helper ──────────────────────────────────────────────────────────────────────
def create_or_update(name: str, validator: dict):
    existing = db.list_collection_names()
    if name not in existing:
        db.create_collection(name, validator=validator)
        print(f"  [+] created  '{name}'")
    else:
        db.command("collMod", name, validator=validator)
        print(f"  [~] updated  '{name}' validator")


# ════════════════════════════════════════════════════════════════════════════════
# 1. users
# ════════════════════════════════════════════════════════════════════════════════
create_or_update("users", {
    "$jsonSchema": {
        "bsonType": "object",
        "required": ["username", "email", "password_hash", "created_at"],
        "properties": {
            "username":      {"bsonType": "string", "minLength": 1, "maxLength": 80},
            "email":         {"bsonType": "string", "minLength": 3, "maxLength": 254},
            "password_hash": {"bsonType": "string"},
            "created_at":    {"bsonType": "date"},
        }
    }
})
db.users.create_index([("email", ASCENDING)],    unique=True, background=True, name="email_unique")
db.users.create_index([("username", ASCENDING)],             background=True, name="username_idx")
print("    indexes: email (unique), username")


# ════════════════════════════════════════════════════════════════════════════════
# 2. history
# ════════════════════════════════════════════════════════════════════════════════
create_or_update("history", {
    "$jsonSchema": {
        "bsonType": "object",
        "required": ["user_id", "claim", "verdict", "confidence", "evidence_count", "created_at"],
        "properties": {
            "user_id":        {"bsonType": "string"},
            "claim":          {"bsonType": "string", "minLength": 1},
            "verdict":        {"bsonType": "string"},
            "confidence":     {"bsonType": "double", "minimum": 0, "maximum": 1},
            "evidence_count": {"bsonType": "int",    "minimum": 0},
            "created_at":     {"bsonType": "date"},
        }
    }
})
db.history.create_index(
    [("user_id", ASCENDING), ("created_at", DESCENDING)],
    background=True, name="user_history_idx"
)
print("    indexes: user_id + created_at")


# ════════════════════════════════════════════════════════════════════════════════
# 3. evidence  (TTL: auto-delete after 30 days)
# ════════════════════════════════════════════════════════════════════════════════
create_or_update("evidence", {
    "$jsonSchema": {
        "bsonType": "object",
        "required": ["text", "source", "created_at"],
        "properties": {
            "text":       {"bsonType": "string", "minLength": 1},
            "source":     {"bsonType": "string"},
            "created_at": {"bsonType": "date"},
        }
    }
})
db.evidence.create_index(
    [("created_at", ASCENDING)],
    expireAfterSeconds=30 * 24 * 3600,
    background=True, name="evidence_ttl"
)
db.evidence.create_index([("source", ASCENDING)], background=True, name="source_idx")
print("    indexes: created_at (TTL 30d), source")


# ════════════════════════════════════════════════════════════════════════════════
# 4. revoked_tokens  (JWT blocklist, TTL = token exp)
# ════════════════════════════════════════════════════════════════════════════════
create_or_update("revoked_tokens", {
    "$jsonSchema": {
        "bsonType": "object",
        "required": ["jti", "exp", "revoked_at"],
        "properties": {
            "jti":        {"bsonType": "string"},
            "exp":        {"bsonType": "date"},
            "revoked_at": {"bsonType": "date"},
        }
    }
})
db.revoked_tokens.create_index(
    [("exp", ASCENDING)],
    expireAfterSeconds=0,          # removed the moment exp is reached
    background=True, name="token_ttl"
)
db.revoked_tokens.create_index([("jti", ASCENDING)], unique=True, background=True, name="jti_unique")
print("    indexes: exp (TTL), jti (unique)")


# ════════════════════════════════════════════════════════════════════════════════
print("\n[DB] All collections and indexes are ready on Atlas! OK")
client.close()