"use server";

import { db } from "@/db";
import { submissions, answers } from "@/db/schema";
import { and, count, eq, lt, lte, or } from "drizzle-orm";
import { revalidatePath } from "next/cache";
import { getServerSession } from "next-auth";
import { authOptions } from "@/lib/auth-options";
import { requireAdmin, requireDiscordId, requireFormAccess } from "@/lib/auth";
import { sse } from "@/lib/sse";
import type { FormAnswerPayload } from "@/lib/form-answer-values";
import {
  normalizeSubmissionAnswers,
  type StoredAnswerSnapshot,
} from "@/lib/submission-intake";
import { submissionWebhookMessage } from "@/lib/submission-webhook";
import { isFormAcceptingSubmissions } from "@/lib/form-availability";

function getSubmissionResultLink(formId: string, submissionId: string) {
  const baseUrl = process.env.BASE_URL || process.env.NEXTAUTH_URL;
  if (!baseUrl) return `/admin/form/${formId}/result/${submissionId}`;
  return new URL(`/admin/form/${formId}/result/${submissionId}`, baseUrl).toString();
}

export async function submitForm(
  formId: string,
  answersList: FormAnswerPayload[],
  targetSubmissionId?: string | null
) {
  const session = await getServerSession(authOptions);
  if (!session?.user) throw new Error("Not authenticated");

  const discordId = await requireDiscordId();
  const userName = session.user.name ?? null;
  const form = await requireFormAccess(formId, discordId);
  if (!isFormAcceptingSubmissions(form)) {
    throw new Error("This form is closed for submissions");
  }

  const questionsList = await db.query.questions.findMany({
    where: (question, { eq }) => eq(question.formId, formId),
    orderBy: (question, { asc }) => asc(question.displayOrder),
  });
  if (questionsList.length === 0) {
    throw new Error("แบบฟอร์มนี้ยังไม่มีคำถาม");
  }

  const normalizedAnswers = normalizeSubmissionAnswers(questionsList, answersList);
  const imageCdnIds = [
    ...new Set(normalizedAnswers.map((answer) => answer.imageCdnId).filter(Boolean)),
  ] as string[];

  if (imageCdnIds.length > 0) {
    const ownedImages = await db.query.cdn.findMany({
      where: (record, { and, eq, inArray }) =>
        and(
          inArray(record.id, imageCdnIds),
          eq(record.ownerDiscordId, discordId)
        ),
      columns: { id: true },
    });
    if (ownedImages.length !== imageCdnIds.length) {
      throw new Error("ข้อมูลรูปภาพไม่ถูกต้อง");
    }
  }

  const result = await db.transaction(async (tx) => {
    const existingSubmission = form.allowMultipleSubmissions
      ? targetSubmissionId
        ? await tx.query.submissions.findFirst({
            where: (submission, { eq, and }) =>
              and(
                eq(submission.id, targetSubmissionId),
                eq(submission.formId, formId),
                eq(submission.userDiscordId, discordId)
              ),
          })
        : null
      : await tx.query.submissions.findFirst({
          where: (submission, { eq, and }) =>
            and(eq(submission.formId, formId), eq(submission.userDiscordId, discordId)),
        });

    if (form.allowMultipleSubmissions && targetSubmissionId && !existingSubmission) {
      throw new Error("ไม่พบคำตอบที่ต้องการแก้ไข");
    }

    let submissionId = "";
    let submittedAt = new Date();
    const isUpdate = Boolean(existingSubmission);
    let oldAnswersDict: Record<string, StoredAnswerSnapshot> = {};

    if (existingSubmission) {
      submissionId = existingSubmission.id;
      submittedAt = existingSubmission.submittedAt;

      const oldAnswersList = await tx.query.answers.findMany({
        where: (answer, { eq }) => eq(answer.submissionId, submissionId),
      });

      oldAnswersDict = oldAnswersList.reduce<Record<string, StoredAnswerSnapshot>>((acc, curr) => {
        acc[curr.questionId] = {
          value: curr.value,
          imageCdnId: curr.imageCdnId ?? null,
        };
        return acc;
      }, {});

      const history = Array.isArray(existingSubmission.editHistory)
        ? [...existingSubmission.editHistory]
        : [];
      history.push({
        editedAt: new Date().toISOString(),
        oldAnswers: oldAnswersDict,
      });

      await tx
        .update(submissions)
        .set({ editHistory: history })
        .where(eq(submissions.id, submissionId));

      await tx.delete(answers).where(eq(answers.submissionId, submissionId));
    } else {
      const [inserted] = await tx
        .insert(submissions)
        .values({
          formId,
          userDiscordId: discordId,
          userName,
        })
        .returning();
      submissionId = inserted.id;
      submittedAt = inserted.submittedAt;
    }

    if (normalizedAnswers.length > 0) {
      await tx.insert(answers).values(
        normalizedAnswers.map((answer) => ({
          submissionId,
          questionId: answer.questionId,
          value: answer.value,
          imageCdnId: answer.imageCdnId,
        }))
      );
    }

    const [submissionStats] = await tx
      .select({ totalAnswers: count() })
      .from(submissions)
      .where(eq(submissions.formId, formId));
    const [queueStats] = await tx
      .select({ queueNumber: count() })
      .from(submissions)
      .where(
        and(
          eq(submissions.formId, formId),
          or(
            lt(submissions.submittedAt, submittedAt),
            and(
              eq(submissions.submittedAt, submittedAt),
              lte(submissions.id, submissionId)
            )
          )
        )
      );

    return {
      submissionId,
      isUpdate,
      oldAnswersDict,
      totalAnswers: submissionStats.totalAnswers,
      queueNumber: queueStats.queueNumber,
    };
  });

  // Send Discord Webhook
  const templateToUse = result.isUpdate
    ? form.discordWebhookUpdateTemplate
    : form.discordWebhookTemplate;

  if (form.discordWebhookUrl) {
    try {
      const submissionLink = getSubmissionResultLink(formId, result.submissionId);
      const message = submissionWebhookMessage({
        template: templateToUse,
        isUpdate: result.isUpdate,
        userName: session.user.name,
        discordId,
        submissionLink,
        questions: questionsList,
        answers: normalizedAnswers,
        oldAnswersByQuestionId: result.oldAnswersDict,
      });

      const response = await fetch(form.discordWebhookUrl, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          content: message,
        }),
      });
      if (!response.ok) {
        const responseBody = await response.text();
        console.error("Discord webhook rejected submission notification", {
          status: response.status,
          statusText: response.statusText,
          response: responseBody.slice(0, 500),
        });
      }
    } catch (e) {
      console.error("Failed to send webhook", e);
    }
  }

  void sse.submissions.pub("update", {
    formId,
    submissionId: result.submissionId,
    action: result.isUpdate ? "updated" : "created",
  });
  revalidatePath(`/admin/form/${formId}/result`);
  return {
    ok: true,
    totalAnswers: result.totalAnswers,
    queueNumber: result.queueNumber,
  };
}

export async function deleteSubmission(id: string) {
  await requireAdmin();

  const submission = await db.query.submissions.findFirst({
    where: (submission, { eq }) => eq(submission.id, id),
    columns: { formId: true },
  });
  await db.delete(submissions).where(eq(submissions.id, id));
  if (submission) {
    void sse.submissions.pub("update", {
      formId: submission.formId,
      submissionId: id,
      action: "deleted",
    });
  }
  revalidatePath("/admin/form");
  return { ok: true };
}

export async function deleteAllSubmissions(formId: string) {
  await requireAdmin();

  await db.delete(submissions).where(eq(submissions.formId, formId));
  void sse.submissions.pub("update", {
    formId,
    action: "deleted",
  });
  revalidatePath(`/admin/form/${formId}/result`);
  return { ok: true };
}

export async function deleteOwnSubmission(formId: string, submissionId?: string | null) {
  const discordId = await requireDiscordId();

  const form = await requireFormAccess(formId, discordId);
  if (form.allowMultipleSubmissions && !submissionId) {
    throw new Error("ไม่พบคำตอบที่ต้องการลบ");
  }

  const where = form.allowMultipleSubmissions
    ? and(
        eq(submissions.id, submissionId!),
        eq(submissions.formId, formId),
        eq(submissions.userDiscordId, discordId)
      )
    : and(
        eq(submissions.formId, formId),
        eq(submissions.userDiscordId, discordId)
      );

  const deleted = await db.delete(submissions).where(where).returning({ id: submissions.id });
  if (form.allowMultipleSubmissions && deleted.length === 0) {
    throw new Error("ไม่พบคำตอบที่ต้องการลบ");
  }
  void sse.submissions.pub("update", {
    formId,
    submissionId: submissionId ?? undefined,
    action: "deleted",
  });
  revalidatePath(`/form`);
  revalidatePath(`/admin/form/${formId}/result`);
  return { ok: true };
}