import json
import os
import shutil
import uuid
from datetime import datetime, timezone
from pathlib import Path


def _safe_filename(name: str) -> str:
    return "".join(c if (c.isalnum() or c in "._- ") else "_" for c in name).strip()


def build_email_dir(base_path: Path, received_datetime: str, message_id: str) -> Path:
    try:
        dt = datetime.fromisoformat(received_datetime.replace("Z", "+00:00"))
    except ValueError:
        dt = datetime.now(timezone.utc)
    date_folder = dt.strftime("%Y-%m-%d")
    time_prefix = dt.strftime("%Y%m%d_%H%M%S")
    folder_name = f"{time_prefix}_{message_id[:8]}"
    return base_path / date_folder / folder_name


async def write_email(
    email_data: dict,
    attachment_bytes: list[tuple[str, str, bytes]],
    base_path: Path,
) -> Path:
    received = email_data.get("receivedDateTime", "")
    message_id = email_data.get("id", str(uuid.uuid4()))
    final_dir = build_email_dir(base_path, received, message_id)

    tmp_dir = base_path / ".tmp" / str(uuid.uuid4())
    tmp_dir.mkdir(parents=True, exist_ok=True)

    try:
        body = email_data.get("body", {})
        if body.get("contentType", "").lower() == "html":
            (tmp_dir / "body.html").write_text(body.get("content", ""), encoding="utf-8")
        else:
            (tmp_dir / "body.txt").write_text(body.get("content", ""), encoding="utf-8")

        if email_data.get("uniqueBody"):
            unique = email_data["uniqueBody"]
            if unique.get("contentType", "").lower() == "html":
                (tmp_dir / "body_unique.html").write_text(
                    unique.get("content", ""), encoding="utf-8"
                )
            else:
                (tmp_dir / "body_unique.txt").write_text(
                    unique.get("content", ""), encoding="utf-8"
                )

        stored_attachments = []
        if attachment_bytes:
            att_dir = tmp_dir / "attachments"
            att_dir.mkdir()
            for filename, content_type, raw in attachment_bytes:
                safe_name = _safe_filename(filename) or "attachment"
                dest = att_dir / safe_name
                dest.write_bytes(raw)
                stored_attachments.append(
                    {
                        "filename": safe_name,
                        "content_type": content_type,
                        "size_bytes": len(raw),
                    }
                )

        from_addr = email_data.get("from", {}).get("emailAddress", {})
        metadata = {
            "message_id": message_id,
            "subject": email_data.get("subject", ""),
            "from": {"name": from_addr.get("name", ""), "address": from_addr.get("address", "")},
            "to": [
                {"name": r.get("emailAddress", {}).get("name", ""),
                 "address": r.get("emailAddress", {}).get("address", "")}
                for r in email_data.get("toRecipients", [])
            ],
            "cc": [
                {"name": r.get("emailAddress", {}).get("name", ""),
                 "address": r.get("emailAddress", {}).get("address", "")}
                for r in email_data.get("ccRecipients", [])
            ],
            "received_datetime": received,
            "has_attachments": email_data.get("hasAttachments", False),
            "attachment_count": len(stored_attachments),
            "attachments": stored_attachments,
            "graph_web_link": email_data.get("webLink", ""),
            "stored_at": datetime.now(timezone.utc).isoformat(),
        }
        (tmp_dir / "metadata.json").write_text(
            json.dumps(metadata, indent=2), encoding="utf-8"
        )

        final_dir.parent.mkdir(parents=True, exist_ok=True)
        if final_dir.exists():
            # Duplicate webhook delivery — email already stored; discard temp copy.
            shutil.rmtree(tmp_dir, ignore_errors=True)
            return final_dir
        os.rename(tmp_dir, final_dir)
        return final_dir

    except Exception:
        shutil.rmtree(tmp_dir, ignore_errors=True)
        raise