Chang Chen

"""
Database query functions for REDB.

Contains all functions that query ClickHouse for sample metadata,
deduplication checks, and catalog lookups.
"""
import os
import ast
import clickhouse_connect
from typing import List, Optional, Dict

from redb import settings
from redb.s3_utils import generate_s3_key_from_hash


def get_supported_formats(magika_filter: Optional[str] = None) -> List[str]:
    """
    Get supported file formats from SUPPORTED_FORMATS env variable or magika_filter override.
    Expected format: SUPPORTED_FORMATS=['pebin', 'elf']

    Args:
        magika_filter: Optional single format to filter by (overrides env var)

    Returns:
        List of supported format strings, defaults to ['pebin'] if not set
    """
    # If magika_filter is provided, use it as the only format
    if magika_filter:
        return [magika_filter]

    formats_str = os.getenv('SUPPORTED_FORMATS', "['pebin']")
    try:
        formats = ast.literal_eval(formats_str)
        if isinstance(formats, list) and all(isinstance(f, str) for f in formats):
            return formats
        else:
            print(f"[WARNING] SUPPORTED_FORMATS must be a list of strings, got: {formats_str}")
            return ['pebin']
    except (ValueError, SyntaxError) as e:
        print(f"[WARNING] Failed to parse SUPPORTED_FORMATS '{formats_str}': {e}")
        return ['pebin']


def get_db_catalog_connection():
    """Create and return a ClickHouse client for catalog queries"""
    return clickhouse_connect.get_client(
        host=os.getenv("DB_HOST"),
        port=int(os.getenv("DB_PORT", "8123")),
        verify=os.getenv("DB_ENFORCE_SSL", "False").lower() == "true",
        username=os.getenv("DB_USER"),
        password=os.getenv("DB_PASSWORD"),
        database=os.getenv("DB_NAME")
    )


def fetch_s3_objects_by_repository(repository: Optional[str], index_prefix: str, decompile: bool, notes: Optional[str] = None, magika_filter: Optional[str] = None, yara_scan: bool = False, force: bool = False) -> List[Dict]:
    """
    Query the ClickHouse repository_upload_sessions table to get samples.
    S3 bucket comes from env var, S3 key is derived from sha256.

    Args:
        repository: Repository name (e.g., "bazaar", "malshare"). If None or "all-repos", queries all repositories.
        index_prefix: Table prefix for checking existing samples
        decompile: Whether we're in decompile mode (affects which table to check for existing)
        notes: Optional filter for notes field
        magika_filter: Optional single filetype to filter by (overrides SUPPORTED_FORMATS)
        yara_scan: Whether we're in YARA-only mode (skips "already processed" check)

    Returns:
        List of dicts with sha256, s3_bucket, s3_key for each sample
    """
    try:
        client = get_db_catalog_connection()
        s3_bucket = os.getenv('S3_BUCKET')

        if not s3_bucket:
            print("[ERROR] S3_BUCKET environment variable is required")
            return []

        # Get supported formats from env or magika_filter override
        supported_formats = get_supported_formats(magika_filter)
        print(f"[INFO] Querying for supported formats: {supported_formats}")

        # Build query - repository filter is optional
        # Join with catalog_samples to get first_seen date
        if repository and repository != "all-repos":
            query = """
                SELECT DISTINCT rus.sha256, rus.filetype_magika, cs.first_seen
                FROM repository_upload_sessions rus
                LEFT JOIN catalog_samples cs ON rus.sha256 = cs.sha256
                WHERE rus.repository = %(repo)s
                  AND rus.filetype_magika IN %(formats)s
            """
            params = {"repo": repository, "formats": supported_formats}
        else:
            # Query all repositories
            query = """
                SELECT DISTINCT rus.sha256, rus.filetype_magika, cs.first_seen
                FROM repository_upload_sessions rus
                LEFT JOIN catalog_samples cs ON rus.sha256 = cs.sha256
                WHERE rus.filetype_magika IN %(formats)s
            """
            params = {"formats": supported_formats}

        if notes:
            query += " AND rus.notes LIKE %(notes)s"
            params["notes"] = f"%{notes}%"

        # Execute query and convert to list of dictionaries
        result = client.query(query, parameters=params)

        # Build rows with s3_bucket and s3_key derived from sha256
        rows = []
        for row in result.result_rows:
            sha256 = row[0]
            # Handle binary string if needed
            if isinstance(sha256, bytes):
                sha256 = sha256.decode('utf-8')

            rows.append({
                'sha256': sha256,
                's3_bucket': s3_bucket,
                's3_key': generate_s3_key_from_hash(sha256),
                'filetype_magika': row[1],
                'first_seen': row[2]  # From catalog_samples (None if not found)
            })

        print(f"[DEBUG] Found {len(rows)} objects in repository_upload_sessions for repository {repository}")

        # Extract SHA256 hashes from the results for bulk checking
        sha256_list = [row.get('sha256') for row in rows if row.get('sha256')]

        if sha256_list and not force:
            # Check which hashes are already in the database
            existing_hashes = is_in_db_bulk(sha256_list, index_prefix, decompile, yara_scan, magika_filter)
            print(f"[INFO] Found {len(existing_hashes)} objects already in database")

            # Filter out rows with existing hashes
            rows = [row for row in rows if row.get('sha256') not in existing_hashes]
            print(f"[INFO] After filtering, {len(rows)} objects remain to be processed")
        elif force:
            print(f"[INFO] Force mode: skipping deduplication check, processing all {len(sha256_list)} objects")

        # Randomize the order of rows before returning
        import random
        random.shuffle(rows)

        return rows
    except Exception as e:
        print(f"[ERROR] Failed to query repository_upload_sessions: {e}")
        return []
    finally:
        if 'client' in locals():
            client.close()


def fetch_s3_objects_by_date_range(
    index_prefix: str,
    decompile: bool,
    start_date: str,
    end_date: str,
    repository: Optional[str] = None,
    notes: Optional[str] = None,
    magika_filter: Optional[str] = None,
    yara_scan: bool = False,
    force: bool = False,
    analyzed: bool = False
) -> List[Dict]:
    """
    Query samples from catalog_samples by first_seen date range, filtered to only include
    samples that exist in repository_upload_sessions (bulk/repo uploads only).

    Args:
        index_prefix: Table prefix for checking existing samples
        decompile: Whether we're in decompile mode
        start_date: Start date (inclusive) in YYYY-MM-DD format
        end_date: End date (exclusive) in YYYY-MM-DD format
        repository: Optional repository filter
        notes: Optional notes filter
        magika_filter: Optional single filetype to filter by (overrides SUPPORTED_FORMATS)
        yara_scan: Whether we're in YARA-only mode (skips "already processed" check)
        analyzed: Filter to only samples already in basic_properties (cross-database join)

    Returns:
        List of dicts with sha256, s3_bucket, s3_key for each sample
    """
    try:
        client = get_db_catalog_connection()
        s3_bucket = os.getenv('S3_BUCKET')

        if not s3_bucket:
            print("[ERROR] S3_BUCKET environment variable is required")
            return []

        # Get supported formats from env or magika_filter override
        supported_formats = get_supported_formats(magika_filter)
        print(f"[INFO] Querying for supported formats: {supported_formats}")

        # Join catalog_samples with repository_upload_sessions to:
        # 1. Filter by first_seen date from catalog_samples
        # 2. Only include samples that exist in repository_upload_sessions (not user uploads)
        # 3. Optionally filter to only already-analyzed samples (in basic_properties)
        analyzed_join = ""
        if analyzed:
            basic_table = f"{index_prefix}_basic_properties"
            analyzed_join = f"INNER JOIN {basic_table} bp ON cs.sha256 = bp.sha256"
            print(f"[INFO] Filtering to already-analyzed samples in {basic_table}")

        query = f"""
            SELECT DISTINCT cs.sha256, rus.filetype_magika, cs.first_seen
            FROM catalog_samples cs
            INNER JOIN repository_upload_sessions rus ON cs.sha256 = rus.sha256
            {analyzed_join}
            WHERE cs.first_seen >= %(start_date)s
              AND cs.first_seen < %(end_date)s
              AND rus.filetype_magika IN %(formats)s
        """
        params = {
            "start_date": start_date,
            "end_date": end_date,
            "formats": supported_formats
        }

        if repository:
            query += " AND rus.repository = %(repo)s"
            params["repo"] = repository

        if notes:
            query += " AND rus.notes LIKE %(notes)s"
            params["notes"] = f"%{notes}%"

        # Execute query
        result = client.query(query, parameters=params)

        # Build rows with s3_bucket and s3_key derived from sha256
        rows = []
        for row in result.result_rows:
            sha256 = row[0]
            # Handle binary string if needed
            if isinstance(sha256, bytes):
                sha256 = sha256.decode('utf-8')

            rows.append({
                'sha256': sha256,
                's3_bucket': s3_bucket,
                's3_key': generate_s3_key_from_hash(sha256),
                'filetype_magika': row[1],
                'first_seen': row[2]  # From catalog_samples
            })

        date_info = f"from {start_date} to {end_date}"
        repo_info = f" for repository {repository}" if repository else ""
        print(f"[DEBUG] Found {len(rows)} objects in catalog_samples {date_info}{repo_info}")

        # Extract SHA256 hashes from the results for bulk checking
        sha256_list = [row.get('sha256') for row in rows if row.get('sha256')]

        if sha256_list and not force:
            # Check which hashes are already in the database
            existing_hashes = is_in_db_bulk(sha256_list, index_prefix, decompile, yara_scan, magika_filter)
            print(f"[INFO] Found {len(existing_hashes)} objects already in database")

            # Filter out rows with existing hashes
            rows = [row for row in rows if row.get('sha256') not in existing_hashes]
            print(f"[INFO] After filtering, {len(rows)} objects remain to be processed")
        elif force:
            print(f"[INFO] Force mode: skipping deduplication check, processing all {len(sha256_list)} objects")

        # Randomize the order of rows before returning
        import random
        random.shuffle(rows)

        return rows
    except Exception as e:
        print(f"[ERROR] Failed to query catalog_samples by date range: {e}")
        return []
    finally:
        if 'client' in locals():
            client.close()


def fetch_analyzed_samples(
    index_prefix: str,
    decompile: bool,
    magika_filter: Optional[str] = None,
    yara_scan: bool = False,
    force: bool = False,
    rerun: bool = False
) -> List[Dict]:
    """
    Query samples from basic_properties that have already been analyzed.
    Useful for reprocessing with decompilation or specific modules.

    Args:
        index_prefix: Table prefix for ClickHouse
        decompile: Whether we're in decompile mode (affects filtering)
        magika_filter: Optional single filetype to filter by (overrides SUPPORTED_FORMATS)
        yara_scan: Whether we're in YARA-only mode (skips decompile filtering)
        force: Skip all deduplication checks when True
        rerun: Query disassembled table directly (only already-disassembled samples)

    Returns:
        List of dicts with sha256, s3_bucket, s3_key for each analyzed sample
    """
    try:
        client = settings.create_clickhouse_client()
        s3_bucket = os.getenv('S3_BUCKET')

        if not s3_bucket:
            print("[ERROR] S3_BUCKET environment variable is required")
            return []

        # Rerun mode: query directly from disassembled_functions_references
        # instead of basic_properties. This targets only samples that already
        # went through binja successfully.
        if rerun:
            disassembled_table = _get_code_dedup_table(magika_filter)
            basic_table = f"{index_prefix}_basic_properties"

            # Join with basic_properties to get filetype_magika and apply format filters
            conditions = []
            params = {}

            if magika_filter:
                conditions.append("bp.filetype_magika = %(magika)s")
                params["magika"] = magika_filter
            else:
                supported_formats = get_supported_formats()
                conditions.append("bp.filetype_magika IN %(formats)s")
                params["formats"] = supported_formats

            query = (
                f"SELECT DISTINCT d.sha256, bp.filetype_magika "
                f"FROM {disassembled_table} d FINAL "
                f"INNER JOIN {basic_table} bp FINAL ON d.sha256 = bp.sha256"
            )
            if conditions:
                query += " WHERE " + " AND ".join(conditions)

            result = client.query(query, parameters=params)

            rows = []
            for row in result.result_rows:
                sha256 = row[0]
                if isinstance(sha256, bytes):
                    sha256 = sha256.decode('utf-8')
                rows.append({
                    'sha256': sha256,
                    's3_bucket': s3_bucket,
                    's3_key': generate_s3_key_from_hash(sha256),
                    'filetype_magika': row[1]
                })

            print(f"[INFO] Rerun mode: found {len(rows)} already-disassembled samples in {disassembled_table}")

            import random
            random.shuffle(rows)
            return rows

        basic_table = f"{index_prefix}_basic_properties"

        # Build query
        conditions = []
        params = {}

        if magika_filter:
            conditions.append("filetype_magika = %(magika)s")
            params["magika"] = magika_filter
        else:
            supported_formats = get_supported_formats()
            conditions.append("filetype_magika IN %(formats)s")
            params["formats"] = supported_formats

        query = f"SELECT DISTINCT sha256, filetype_magika FROM {basic_table} FINAL"
        if conditions:
            query += " WHERE " + " AND ".join(conditions)

        result = client.query(query, parameters=params)

        rows = []
        for row in result.result_rows:
            sha256 = row[0]
            if isinstance(sha256, bytes):
                sha256 = sha256.decode('utf-8')
            rows.append({
                'sha256': sha256,
                's3_bucket': s3_bucket,
                's3_key': generate_s3_key_from_hash(sha256),
                'filetype_magika': row[1]
            })

        print(f"[DEBUG] Found {len(rows)} analyzed samples in {basic_table}")

        # In YARA-only mode, filter out already-scanned samples (unless force)
        if yara_scan and not force:
            sha256_list = [r['sha256'] for r in rows]
            if sha256_list:
                already_scanned = _check_yara_matches_bulk(sha256_list)
                print(f"[INFO] Found {len(already_scanned)} already YARA-scanned samples")
                rows = [r for r in rows if r['sha256'].lower() not in already_scanned]
                print(f"[INFO] After filtering, {len(rows)} samples remain for YARA scanning")
        # In decompile mode, filter out already-disassembled samples (unless force)
        # We check disassembly (not decompilation) because disassembly is the ground truth:
        # disassembly always succeeds, decompilation may not, so a missing decompile
        # entry doesn't mean the sample wasn't analyzed.
        elif decompile and not force:
            sha256_list = [r['sha256'] for r in rows]
            if sha256_list:
                disassembled_table = _get_code_dedup_table(magika_filter)
                batch_size = 3900

                already_disassembled = set()
                for i in range(0, len(sha256_list), batch_size):
                    batch = sha256_list[i:i+batch_size]
                    placeholders = "','".join(batch)
                    check_query = f"SELECT DISTINCT sha256 FROM {disassembled_table} FINAL WHERE sha256 IN ('{placeholders}')"
                    check_result = client.query(check_query)
                    for check_row in check_result.result_rows:
                        hash_value = check_row[0]
                        if isinstance(hash_value, bytes):
                            hash_value = hash_value.decode('utf-8')
                        already_disassembled.add(hash_value)

                print(f"[INFO] Found {len(already_disassembled)} already-disassembled samples")
                rows = [r for r in rows if r['sha256'] not in already_disassembled]
                print(f"[INFO] After filtering, {len(rows)} samples remain for decompilation")
        elif force:
            print(f"[INFO] Force mode: returning all {len(rows)} analyzed samples")

        # Randomize the order of rows before returning
        import random
        random.shuffle(rows)

        return rows
    except Exception as e:
        print(f"[ERROR] Failed to query analyzed samples: {e}")
        return []
    finally:
        if 'client' in locals():
            client.close()


def is_in_db(sha256, index_prefix, client=None):
    """
    Check if a sample with given SHA256 already exists in the database

    Args:
        sha256: File's SHA256 hash
        index_prefix: Table prefix for ClickHouse
        client: Optional ClickHouse client instance

    Returns:
        bool: True if file exists, False otherwise
    """
    table = f"{index_prefix}_basic_properties"
    close_client = False

    try:
        if client is None:
            client = settings.create_clickhouse_client()
            close_client = True

        # No need for FINAL when checking existence with LIMIT 1
        # Any version of the row proves the sample exists
        query = f"SELECT 1 FROM {table} WHERE sha256 = %(sha256)s LIMIT 1"
        result = client.query(query, parameters={"sha256": sha256})

        return len(result.result_rows) > 0
    except Exception as e:
        print(f"[ERROR] Failed to check if file is in DB: {e}")
        return False
    finally:
        if close_client and client:
            client.close()


def _get_code_dedup_table(magika_filter: Optional[str] = None) -> str:
    """
    Return the code-analysis table used for deduplication based on filetype.

    APK samples are disassembled into code_apk_smali_methods_references;
    everything else uses {CLICKHOUSE_CODE_PREFIX}_disassembled_functions_references.
    """
    if magika_filter == "apk":
        return "code_apk_smali_methods_references"
    code_prefix = os.getenv("CLICKHOUSE_CODE_PREFIX", "code_binja")
    return f"{code_prefix}_disassembled_functions_references"


def is_in_code_db(sha256, client=None, filetype=None):
    """
    Check if a sample with given SHA256 has already been disassembled.

    Args:
        sha256: File's SHA256 hash
        client: Optional ClickHouse client instance
        filetype: Magika filetype label (e.g. 'apk') to pick the right code table

    Returns:
        bool: True if file has been disassembled, False otherwise
    """
    table = _get_code_dedup_table(filetype)
    close_client = False

    try:
        if client is None:
            client = settings.create_clickhouse_client()
            close_client = True

        query = f"SELECT 1 FROM {table} WHERE sha256 = %(sha256)s LIMIT 1"
        result = client.query(query, parameters={"sha256": sha256})

        return len(result.result_rows) > 0
    except Exception as e:
        print(f"[ERROR] Failed to check if file is in code DB: {e}")
        return False
    finally:
        if close_client and client:
            client.close()


def _check_yara_matches_bulk(sha256_list):
    """
    Check which samples have already been YARA-scanned by querying yara_matches.

    The yara_matches table uses FixedString(32) binary sha256, so we convert
    hex strings with unhex().

    Args:
        sha256_list: List of hex SHA256 strings to check

    Returns:
        set: Set of hex SHA256 hashes that already have YARA matches
    """
    # unhex('64hexchars') adds 9 chars overhead per entry vs plain '64hexchars'.
    # 3900 works for plain strings (~67 chars each = 261K) but overflows
    # max_query_size (262144) with unhex() wrapping (~73 chars each = 285K).
    # 3500 × 73 = 255K stays safely under the limit.
    batch_size = 3500
    already_scanned = set()

    try:
        client = settings.create_clickhouse_client()

        total_batches = (len(sha256_list) + batch_size - 1) // batch_size
        for batch_num, i in enumerate(range(0, len(sha256_list), batch_size), 1):
            batch = sha256_list[i:i+batch_size]
            unhex_list = ",".join(f"unhex('{h}')" for h in batch)
            query = f"SELECT DISTINCT hex(sha256) FROM yara_matches FINAL WHERE sha256 IN ({unhex_list})"
            result = client.query(query)
            for row in result.result_rows:
                hash_value = row[0]
                if isinstance(hash_value, bytes):
                    hash_value = hash_value.decode('utf-8')
                already_scanned.add(hash_value.lower())

            if batch_num % 100 == 0 or batch_num == total_batches:
                print(f"[INFO] YARA dedup progress: batch {batch_num}/{total_batches}, found {len(already_scanned)} so far")

        print(f"[INFO] YARA dedup: found {len(already_scanned)} already-scanned samples")
        return already_scanned

    except Exception as e:
        raise RuntimeError(f"YARA dedup query failed — aborting to prevent reprocessing all samples: {e}")
    finally:
        if 'client' in locals():
            client.close()


def is_in_db_bulk(sha256_list, index_prefix, decompile, yara_scan=False, magika_filter=None):
    """
    Check which samples from a list of SHA256 hashes should be skipped.

    Args:
        sha256_list: List of SHA256 hashes to check
        index_prefix: Table prefix for ClickHouse
        decompile: Whether we're in decompile mode
        yara_scan: Whether we're in YARA-only mode (checks yara_matches table)
        magika_filter: Magika filetype label (e.g. 'apk') to pick the right code table

    Returns:
        set: Set of SHA256 hashes that should be skipped
    """
    if not sha256_list:
        return set()

    # YARA-only mode: check yara_matches table for already-scanned samples
    if yara_scan:
        return _check_yara_matches_bulk(sha256_list)

    basic_table = f"{index_prefix}_basic_properties"
    batch_size = 3900

    try:
        client = settings.create_clickhouse_client()

        # Step 1: Check basic_properties (required for both modes)
        in_basic_properties = set()
        for i in range(0, len(sha256_list), batch_size):
            batch = sha256_list[i:i+batch_size]
            placeholders = "','".join(batch)
            query = f"SELECT DISTINCT sha256 FROM {basic_table} FINAL WHERE sha256 IN ('{placeholders}')"
            result = client.query(query)
            for row in result.result_rows:
                hash_value = row[0]
                if isinstance(hash_value, bytes):
                    hash_value = hash_value.decode('utf-8')
                in_basic_properties.add(hash_value)

        if not decompile:
            # Analysis mode: skip samples already in basic_properties
            return in_basic_properties

        # Decompile mode: skip samples NOT in basic_properties + already decompiled
        not_in_basic = set(sha256_list) - in_basic_properties

        if not in_basic_properties:
            return set(sha256_list)  # None ready for decompilation

        # Step 2: Check disassembled table for samples that ARE in basic_properties
        # Disassembly is the ground truth for code analysis (it always succeeds,
        # unlike decompilation which may fail).
        disassembled_table = _get_code_dedup_table(magika_filter)

        already_disassembled = set()
        samples_to_check = list(in_basic_properties)
        for i in range(0, len(samples_to_check), batch_size):
            batch = samples_to_check[i:i+batch_size]
            placeholders = "','".join(batch)
            query = f"SELECT DISTINCT sha256 FROM {disassembled_table} FINAL WHERE sha256 IN ('{placeholders}')"
            result = client.query(query)
            for row in result.result_rows:
                hash_value = row[0]
                if isinstance(hash_value, bytes):
                    hash_value = hash_value.decode('utf-8')
                already_disassembled.add(hash_value)

        return not_in_basic | already_disassembled

    except Exception as e:
        print(f"[ERROR] Failed to check hashes in DB: {e}")
        return set()
    finally:
        if 'client' in locals():
            client.close()