import json
import time
from pathlib import Path
from django.http import StreamingHttpResponse, JsonResponse
from django.conf import settings
from django.core.validators import validate_email
from django.core.exceptions import ValidationError
from django.views.decorators.clickjacking import xframe_options_exempt
from django.views.decorators.csrf import csrf_exempt


def send_progress_update(step, message, progress):
    """Helper to send a progress update as JSON"""
    return json.dumps({"step": step, "message": message, "progress": progress}) + "\n"


@xframe_options_exempt
@csrf_exempt
def submit_quote(request):
    """
    Handle quote submission with progress updates.
    Steps:
    1. Upload files
    2. Save files
    3. Send email
    4. Verify email sent
    """
    if request.method != "POST":
        return JsonResponse({"error": "Method not allowed"}, status=405)

    # Read form data first (files need to be read from request)
    email = request.POST.get("email", "").strip()
    notes = request.POST.get("notes", "").strip()
    files = request.FILES.getlist("files")

    def process_quote():
        try:
            # Step 1: Validate email
            yield send_progress_update(1, "Validating email address...", 5)

            if not email:
                raise ValueError("Email is required")

            try:
                validate_email(email)
            except ValidationError:
                raise ValueError(f"Invalid email address: {email}")

            yield send_progress_update(1, "Email validated successfully", 10)

            # Step 2: Create submission & upload files
            from quotes.models import Submission, SubmissionFile

            # Create a Submission entry
            submission = Submission.objects.create(
                email=email,
                description=notes,
            )

            yield send_progress_update(2, "Created submission entry...", 15)

            # Save each file and register in the model
            total_files = len(files)
            file_objs = []
            for idx, file in enumerate(files, start=1):
                # Use the original filename and save to MEDIA_ROOT/submission_<id>_filename
                submission_dir = (
                    Path(settings.MEDIA_ROOT) / f"submission_{submission.id}"
                )
                submission_dir.mkdir(parents=True, exist_ok=True)
                target_path = submission_dir / file.name

                with open(target_path, "wb") as f:
                    for chunk in file.chunks():
                        f.write(chunk)

                # Register file in SubmissionFile model
                rel_path = (Path(f"submission_{submission.id}") / file.name).as_posix()
                submission_file = SubmissionFile.objects.create(
                    submission=submission,
                    original_filename=file.name,
                    path=rel_path,
                    file_size=file.size,
                )
                file_objs.append(submission_file)
                yield send_progress_update(
                    2,
                    f"Uploaded file {idx} of {total_files}: {file.name}",
                    15 + int((idx / total_files) * 30),
                )

            yield send_progress_update(3, "Files saved...", 50)

            # Step 4: Send emails
            from quotes.email_utils import send_submission_emails

            yield send_progress_update(4, "Sending notification email...", 70)
            owner_sent, submitter_sent = send_submission_emails(submission)
            time.sleep(0.3)

            yield send_progress_update(4, "Sending confirmation email...", 75)
            time.sleep(0.3)

            # Verify emails were sent
            if not owner_sent and getattr(settings, "OWNER_EMAIL", ""):
                yield send_progress_update(
                    "warning",
                    "Warning: Owner notification email may not have been sent",
                    75,
                )
            if not submitter_sent:
                yield send_progress_update(
                    "warning", "Warning: Confirmation email may not have been sent", 75
                )

            # Complete
            yield send_progress_update(
                5,
                "Quote request submitted successfully! Check your email for confirmation.",
                100,
            )

        except Exception as e:
            yield send_progress_update("error", f"An error occurred: {str(e)}", 0)

    response = StreamingHttpResponse(process_quote(), content_type="text/event-stream")
    response["Cache-Control"] = "no-cache"
    response["X-Accel-Buffering"] = "no"
    return response