services/forensic_metadata_service.py

"""
Forensic Metadata service — produces a comprehensive forensic metadata
report from an image's embedded metadata.

Combines:
  - EXIF (via cores.metadata.extract_all)
  - GPS coordinates (via cores.metadata.gps_to_coords)
  - ICC profile (via cores.metadata.extract_icc_profile)
  - Thumbnail extraction (via cores.metadata.extract_thumbnail)
  - Editing history (via cores.metadata.extract_editing_history)
  - Camera fingerprint (via cores.metadata.camera_fingerprint)
  - Compression analysis (via cores.metadata.analyze_compression)
  - Timestamp normalization (via cores.metadata.normalize_timestamp)
  - Lens info (via cores.metadata.extract_lens_info)

Pure Pillow + NumPy — no external deps.
"""

from __future__ import annotations

import time

from cores.metadata import (
    extract_all,
    extract_icc_profile,
    extract_thumbnail,
    extract_embedded_preview,
    extract_editing_history,
    camera_fingerprint,
    analyze_compression,
    normalize_timestamp,
    extract_lens_info,
)
from models.jobs import JobRequest
from models.reports import ForensicMetadataReport
from pipeline import InputValidator, ImagePreprocessor, ImageHasher
from utils.logging import execution_context, new_execution_id


class ForensicMetadataService:
    """Produces a ForensicMetadataReport from image metadata."""

    def __init__(
        self,
        validator: InputValidator,
        preprocessor: ImagePreprocessor,
        hasher: ImageHasher,
    ) -> None:
        self._validator = validator
        self._preprocessor = preprocessor
        self._hasher = hasher

    async def analyze(self, request: JobRequest) -> dict:
        """Extract comprehensive forensic metadata from an image."""
        eid = new_execution_id()
        with execution_context(execution_id=eid, provider_id="forensic_metadata_service"):
            t0 = time.perf_counter()

            vr = self._validator.validate(
                image_url=request.image_url,
                image_base64=request.image_base64,
            )
            if not vr.valid:
                return {"success": False, "error": vr.error, "error_type": "ValidationError"}

            if vr.source == "url":
                pre = self._preprocessor.from_url(request.image_url)
            else:
                pre = self._preprocessor.from_bytes(vr.image_bytes, vr.source)

            original_bytes = pre.original_bytes or vr.image_bytes
            if not original_bytes:
                return {"success": False, "error": "No original bytes available for metadata extraction",
                        "error_type": "ValidationError"}

            # Extract everything in one pass
            meta = extract_all(original_bytes)

            # ICC profile
            icc = extract_icc_profile(original_bytes)

            # Thumbnail
            thumb = extract_thumbnail(original_bytes)

            # Embedded preview
            has_preview = extract_embedded_preview(original_bytes)

            # Editing history
            edit_history = extract_editing_history(meta.get("exif", {}))

            # Lens info
            lens = extract_lens_info(meta.get("exif", {}))

            # Camera fingerprint
            fingerprint = camera_fingerprint(original_bytes, (pre.height, pre.width))

            # Compression analysis
            compression = analyze_compression(original_bytes)

            # Timestamp normalization
            ts_normalized = None
            if meta.get("capture_time"):
                ts_normalized = normalize_timestamp(meta["capture_time"])

            elapsed = (time.perf_counter() - t0) * 1000.0

            report = ForensicMetadataReport(
                format=meta.get("format"),
                exif=meta.get("exif", {}),
                xmp={} if not meta.get("xmp") else {"raw_length": len(meta["xmp"])},
                iptc=meta.get("iptc", {}),
                icc_profile=icc,
                gps=meta.get("gps_coords"),
                camera_make=meta.get("camera_make"),
                camera_model=meta.get("camera_model"),
                lens_model=lens,
                software=meta.get("software"),
                capture_time=meta.get("capture_time"),
                capture_time_iso=ts_normalized.get("iso") if ts_normalized else None,
                timezone_estimate=ts_normalized.get("timezone") if ts_normalized else None,
                editing_history=edit_history,
                thumbnail_extracted=bool(thumb and thumb.get("present")),
                embedded_preview=has_preview,
                camera_fingerprint=fingerprint,
                compression_analysis=compression,
            )

            return {
                "success": True,
                "forensic_metadata": report.model_dump(),
                "elapsed_ms": round(elapsed, 3),
            }