'use server';

import db from '@/db/db';
import { revalidateI18nPaths } from '@/lib/revalidate';
import {
  and,
  asc,
  count,
  desc,
  eq,
  ilike,
  or,
} from 'drizzle-orm';

import {
  approvalTemplates,
  approvalTemplateVariables,
  approvalTemplateHistory,
} from '@/db/schema/knox/approvals';

import { filterColumns } from '@/lib/filter-columns';
import { GetApprovalTemplateSchema } from './validations';

// ---------------------------------------------
// Types
// ---------------------------------------------

export type ApprovalTemplate = typeof approvalTemplates.$inferSelect;
export type ApprovalTemplateVariable =
  typeof approvalTemplateVariables.$inferSelect;
export type ApprovalTemplateHistory =
  typeof approvalTemplateHistory.$inferSelect;
// ---------------------------------------------
// Revalidation helpers
// ---------------------------------------------
async function revalidateApprovalTemplatesPaths() {
  await revalidateI18nPaths('/evcp/approval/template');
}


export interface ApprovalTemplateWithVariables extends ApprovalTemplate {
  variables: ApprovalTemplateVariable[];
}

// ---------------------------------------------
// List & read helpers
// ---------------------------------------------

export async function getApprovalTemplateList(input: GetApprovalTemplateSchema) {
  const offset = (input.page - 1) * input.perPage;

  /* ------------------------------------------------------------------
   * WHERE 절 구성
   * ----------------------------------------------------------------*/
  const advancedWhere = filterColumns({
    table: approvalTemplates,
    filters: input.filters,
    joinOperator: input.joinOperator,
  });

  // 전역 검색 (name, subject, description, category)
  let globalWhere;
  if (input.search) {
    const s = `%${input.search}%`;
    globalWhere = or(
      ilike(approvalTemplates.name, s),
      ilike(approvalTemplates.subject, s),
      ilike(approvalTemplates.description, s),
      ilike(approvalTemplates.category, s),
    );
  }

  const conditions = [];

  if (advancedWhere) conditions.push(advancedWhere);
  if (globalWhere) conditions.push(globalWhere);

  let finalWhere;
  if (conditions.length > 0) {
    finalWhere = conditions.length > 1 ? and(...conditions) : conditions[0];
  }

  // 아니면 ilike, inArray, gte 등으로 where 절 구성
  const where = finalWhere;

  /* ------------------------------------------------------------------
   * ORDER BY 절 구성
   * ----------------------------------------------------------------*/
  let orderBy;
  try {
    orderBy = input.sort && input.sort.length > 0
      ? input.sort
          .map((item) => {
            if (!item || !item.id || typeof item.id !== "string" || !(item.id in approvalTemplates)) return null;
            const col = approvalTemplates[item.id as keyof typeof approvalTemplates];
            return item.desc ? desc(col) : asc(col);
          })
          .filter((v): v is Exclude<typeof v, null> => v !== null)
      : [desc(approvalTemplates.updatedAt)];
  } catch (orderErr) {
    console.error("Error building order by:", orderErr);
    orderBy = [desc(approvalTemplates.updatedAt)];
  }

  /* ------------------------------------------------------------------
   * 데이터 조회
   * ----------------------------------------------------------------*/
  const data = await db
    .select()
    .from(approvalTemplates)
    .where(where)
    .orderBy(...orderBy)
    .limit(input.perPage)
    .offset(offset);

  const totalResult = await db
    .select({ count: count() })
    .from(approvalTemplates)
    .where(where);

  const total = totalResult[0]?.count ?? 0;
  const pageCount = Math.ceil(total / input.perPage);

  return {
    data,
    pageCount,
  };
}

// ----------------------------------------------------
// Get single template + variables
// ----------------------------------------------------
export async function getApprovalTemplate(id: string): Promise<ApprovalTemplateWithVariables | null> {
  const [template] = await db
    .select()
    .from(approvalTemplates)
    .where(eq(approvalTemplates.id, id))
    .limit(1);

  if (!template) return null;

  const variables = await db
    .select()
    .from(approvalTemplateVariables)
    .where(eq(approvalTemplateVariables.approvalTemplateId, id))
    .orderBy(approvalTemplateVariables.variableName);

  return {
    ...template,
    variables,
  };
}

// ----------------------------------------------------
// Create template
// ----------------------------------------------------
interface CreateInput {
  name: string;
  subject: string;
  content: string;
  category?: string;
  description?: string;
  createdBy: number;
  approvalLineId?: string | null;
  variables?: Array<{
    variableName: string;
    variableType: string;
    defaultValue?: string;
    description?: string;
  }>;
}

export async function createApprovalTemplate(data: CreateInput): Promise<ApprovalTemplateWithVariables> {
  // 중복 이름 체크 (옵션)
  const existing = await db
    .select({ id: approvalTemplates.id })
    .from(approvalTemplates)
    .where(eq(approvalTemplates.name, data.name))
    .limit(1);

  if (existing.length > 0) {
    throw new Error('이미 존재하는 템플릿 이름입니다.');
  }

  const [newTemplate] = await db
    .insert(approvalTemplates)
    .values({
      name: data.name,
      subject: data.subject,
      content: data.content,
      category: data.category,
      description: data.description,
      approvalLineId: data.approvalLineId ?? null,
      createdBy: data.createdBy,
    })
    .returning();

  if (data.variables?.length) {
    const variableRows = data.variables.map((v) => ({
      approvalTemplateId: newTemplate.id,
      variableName: v.variableName,
      variableType: v.variableType,
      defaultValue: v.defaultValue,
      description: v.description,
      createdBy: data.createdBy,
    }));
    await db.insert(approvalTemplateVariables).values(variableRows);
  }

  const result = await getApprovalTemplate(newTemplate.id);
  if (!result) throw new Error('생성된 템플릿을 조회할 수 없습니다.');
  await revalidateApprovalTemplatesPaths();
  return result;
}

// ----------------------------------------------------
// Update template
// ----------------------------------------------------
interface UpdateInput {
  name?: string;
  subject?: string;
  content?: string;
  description?: string;
  category?: string;
  approvalLineId?: string | null;
  updatedBy: number;
}

export async function updateApprovalTemplate(id: string, data: UpdateInput): Promise<ApprovalTemplateWithVariables> {
  const existing = await getApprovalTemplate(id);
  if (!existing) throw new Error('템플릿을 찾을 수 없습니다.');

  // 버전 계산 - 현재 히스토리 카운트 + 1
  const versionResult = await db
    .select({ count: count() })
    .from(approvalTemplateHistory)
    .where(eq(approvalTemplateHistory.templateId, id));
  const nextVersion = Number(versionResult[0]?.count ?? 0) + 1;

  // 히스토리 저장
  await db.insert(approvalTemplateHistory).values({
    templateId: id,
    version: nextVersion,
    subject: existing.subject,
    content: existing.content,
    changeDescription: '템플릿 업데이트',
    changedBy: data.updatedBy,
  });

  // 템플릿 업데이트
  await db
    .update(approvalTemplates)
    .set({
      name: data.name ?? existing.name,
      subject: data.subject ?? existing.subject,
      content: data.content ?? existing.content,
      description: data.description ?? existing.description,
      category: data.category ?? existing.category,
      approvalLineId: data.approvalLineId === undefined ? existing.approvalLineId : data.approvalLineId,
      updatedAt: new Date(),
    })
    .where(eq(approvalTemplates.id, id));

  const result = await getApprovalTemplate(id);
  if (!result) throw new Error('업데이트된 템플릿을 조회할 수 없습니다.');
  await revalidateApprovalTemplatesPaths();
  return result;
}

// ----------------------------------------------------
// Server Actions
// ----------------------------------------------------
export async function updateApprovalTemplateAction(id: string, data: UpdateInput) {
  try {
    const updated = await updateApprovalTemplate(id, data)
    return { success: true, data: updated }
  } catch (error) {
    return {
      success: false,
      error: error instanceof Error ? error.message : '업데이트에 실패했습니다.'
    }
  }
}

// ----------------------------------------------------
// Duplicate template
// ----------------------------------------------------
export async function duplicateApprovalTemplate(
  id: string,
  newName: string,
  createdBy: number,
): Promise<{ success: boolean; error?: string; data?: ApprovalTemplate }> {
  try {
    const existing = await getApprovalTemplate(id)
    if (!existing) return { success: false, error: '템플릿을 찾을 수 없습니다.' }

    // 새 템플릿 생성
    const duplicated = await createApprovalTemplate({
      name: newName,
      subject: existing.subject,
      content: existing.content,
      category: existing.category ?? undefined,
      description: existing.description ? `${existing.description} (복사본)` : undefined,
      createdBy,
      variables: existing.variables?.map((v) => ({
        variableName: v.variableName,
        variableType: v.variableType,
        defaultValue: v.defaultValue ?? undefined,
        description: v.description ?? undefined,
      })) as Array<{
        variableName: string;
        variableType: string;
        defaultValue?: string;
        description?: string;
      }>,
    })

    return { success: true, data: duplicated }
  } catch (error) {
    return { success: false, error: error instanceof Error ? error.message : '복제에 실패했습니다.' }
  }
}

// ----------------------------------------------------
// Delete (soft delete X -> 실제 삭제)
// ----------------------------------------------------
export async function deleteApprovalTemplate(id: string): Promise<{ success: boolean; error?: string }> {
  try {
    await db.delete(approvalTemplates).where(eq(approvalTemplates.id, id));
    await revalidateApprovalTemplatesPaths();
    return { success: true };
  } catch (error) {
    return {
      success: false,
      error: error instanceof Error ? error.message : '삭제에 실패했습니다.',
    };
  }
}