from __future__ import annotations

from datetime import datetime

from app.models.entities import Blob


def build_blob_storage_key(blob: Blob) -> str:
    content_hash = blob.content_hash
    prefix_one = content_hash[:2] if len(content_hash) >= 2 else "xx"
    prefix_two = content_hash[2:4] if len(content_hash) >= 4 else "xx"
    kind = blob.kind or "blob"
    return f"objects/{kind}/sha256/{prefix_one}/{prefix_two}/{content_hash}.blob"


def build_preview_artifact_storage_key(*, artifact_type: str, blob: Blob) -> str:
    content_hash = blob.content_hash
    prefix_one = content_hash[:2] if len(content_hash) >= 2 else "xx"
    prefix_two = content_hash[2:4] if len(content_hash) >= 4 else "xx"
    artifact_segment = _normalize_segment(artifact_type)
    return f"objects/preview/{artifact_segment}/sha256/{prefix_one}/{prefix_two}/{content_hash}.blob"


def build_export_snapshot_storage_key(*, exported_at: datetime, digest: str) -> str:
    year = f"{exported_at.year:04d}"
    month = f"{exported_at.month:02d}"
    day = f"{exported_at.day:02d}"
    normalized_digest = _normalize_segment(digest) or "snapshot"
    return f"objects/export/metadata/{year}/{month}/{day}/{normalized_digest}.json"


def build_manifest_storage_key(*, scope: str, identifier: str) -> str:
    normalized_scope = _normalize_segment(scope) or "general"
    normalized_identifier = _normalize_segment(identifier) or "manifest"
    return f"objects/manifest/{normalized_scope}/{normalized_identifier}.json"


def _normalize_segment(value: str) -> str:
    cleaned = "".join(char if char.isalnum() or char in {"-", "_"} else "-" for char in value.strip().lower())
    while "--" in cleaned:
        cleaned = cleaned.replace("--", "-")
    return cleaned.strip("-_")