import { and, asc, desc, eq, isNull, ne, sql } from "drizzle-orm";
import type { DrizzleD1Database } from "drizzle-orm/d1";
import {
  blogKeywords,
  cases,
  contentItems,
  CONTENT_KINDS,
  posts,
  siteSettings,
  type BlogKeyword,
  type CaseStudy,
  type ContentItem,
  type ContentKind,
  type Post,
} from "../db/schema";
import * as schema from "../db/schema";

export type Db = DrizzleD1Database<typeof schema>;
export type Settings = Record<string, string>;

export type HomeData = {
  settings: Settings;
  services: ContentItem[];
  features: ContentItem[];
  steps: ContentItem[];
  faqs: ContentItem[];
  cases: CaseStudy[];
};

export async function getSettings(db: Db): Promise<Settings> {
  const rows = await db.select().from(siteSettings);
  return Object.fromEntries(rows.map((r) => [r.key, r.value]));
}

export async function getItems(db: Db, kind: ContentKind): Promise<ContentItem[]> {
  return db
    .select()
    .from(contentItems)
    .where(and(eq(contentItems.kind, kind), eq(contentItems.status, "published")))
    .orderBy(asc(contentItems.sortOrder));
}

export async function getCases(db: Db): Promise<CaseStudy[]> {
  return db
    .select()
    .from(cases)
    .where(eq(cases.status, "published"))
    .orderBy(asc(cases.sortOrder));
}

export async function getPublishedPosts(db: Db): Promise<Post[]> {
  return db
    .select()
    .from(posts)
    .where(eq(posts.status, "published"))
    .orderBy(desc(posts.publishedAt));
}

export async function getPostBySlug(db: Db, slug: string): Promise<Post | null> {
  const [post] = await db
    .select()
    .from(posts)
    .where(and(eq(posts.slug, slug), eq(posts.status, "published")))
    .limit(1);
  return post ?? null;
}

export async function getKeywords(db: Db): Promise<BlogKeyword[]> {
  return db
    .select()
    .from(blogKeywords)
    .orderBy(asc(blogKeywords.createdAt), asc(blogKeywords.id));
}

export type DashboardData = {
  posts: { published: number; draft: number };
  cases: { published: number; draft: number };
  content: { kind: ContentKind; published: number; draft: number }[];
  keywords: { pending: number; generated: number; skipped: number };
  recentPosts: Post[];
  postsWithoutCover: number;
};

/** 後台總覽用嘅統計（只讀 DB；AI secrets 由頁面層提供）。 */
export async function getDashboardData(db: Db): Promise<DashboardData> {
  const [postRows, caseRows, itemRows, kwRows, recentPosts, noCover] = await Promise.all([
    db.select({ status: posts.status, n: sql<number>`count(*)` }).from(posts).groupBy(posts.status),
    db.select({ status: cases.status, n: sql<number>`count(*)` }).from(cases).groupBy(cases.status),
    db
      .select({ kind: contentItems.kind, status: contentItems.status, n: sql<number>`count(*)` })
      .from(contentItems)
      .groupBy(contentItems.kind, contentItems.status),
    db
      .select({ status: blogKeywords.status, n: sql<number>`count(*)` })
      .from(blogKeywords)
      .groupBy(blogKeywords.status),
    db.select().from(posts).orderBy(desc(posts.updatedAt)).limit(5),
    db.select({ n: sql<number>`count(*)` }).from(posts).where(isNull(posts.coverImage)),
  ]);

  const pick = <T extends string>(rows: { status: T; n: number }[], status: T) =>
    Number(rows.find((r) => r.status === status)?.n ?? 0);

  return {
    posts: { published: pick(postRows, "published"), draft: pick(postRows, "draft") },
    cases: { published: pick(caseRows, "published"), draft: pick(caseRows, "draft") },
    content: CONTENT_KINDS.map((kind) => ({
      kind,
      published: Number(itemRows.find((r) => r.kind === kind && r.status === "published")?.n ?? 0),
      draft: Number(itemRows.find((r) => r.kind === kind && r.status === "draft")?.n ?? 0),
    })),
    keywords: {
      pending: pick(kwRows, "pending"),
      generated: pick(kwRows, "generated"),
      skipped: pick(kwRows, "skipped"),
    },
    recentPosts,
    postsWithoutCover: Number(noCover[0]?.n ?? 0),
  };
}

export async function getHomeData(db: Db): Promise<HomeData> {
  const [settings, services, features, steps, faqs, caseList] = await Promise.all([
    getSettings(db),
    getItems(db, "service"),
    getItems(db, "feature"),
    getItems(db, "step"),
    getItems(db, "faq"),
    getCases(db),
  ]);
  return { settings, services, features, steps, faqs, cases: caseList };
}

export function digits(input: string | undefined): string {
  return (input ?? "").replace(/\D/g, "");
}

export function whatsappHref(
  settings: Settings,
  text = "你好，我想查詢村屋太陽能安裝，想預約免費評估。",
): string {
  return `https://api.whatsapp.com/send?phone=${digits(settings.whatsapp)}&text=${encodeURIComponent(text)}`;
}

export function telHref(settings: Settings): string {
  const phone = (settings.phone ?? "").replace(/[^\d+]/g, "");
  return `tel:${phone}`;
}

export function mailHref(settings: Settings): string {
  return `mailto:${settings.email ?? ""}?subject=${encodeURIComponent("查詢村屋太陽能安裝")}`;
}

export function formatDate(d: Date | null | undefined): string {
  if (!d) return "";
  return new Date(d).toLocaleDateString("zh-Hant-HK", {
    year: "numeric",
    month: "long",
    day: "numeric",
  });
}

/** slug 撞咗就加 -2、-3…；selfId 用喺更新自己時排除自己。 */
export async function uniqueSlug(db: Db, base: string, selfId?: string): Promise<string> {
  let candidate = base;
  for (let i = 2; i < 50; i++) {
    const rows = await db
      .select({ id: posts.id })
      .from(posts)
      .where(selfId ? and(eq(posts.slug, candidate), ne(posts.id, selfId)) : eq(posts.slug, candidate))
      .limit(1);
    if (rows.length === 0) return candidate;
    candidate = `${base}-${i}`;
  }
  return `${base}-${Date.now()}`;
}