import type { DatabaseClient } from "./database";
import { getRuntimeEnv } from "./runtime-env";
import {
  sendAppChatMessage,
  sendWecomAppMessage,
  WecomClientError,
  type WecomConfig,
} from "./wecom-client";
import {
  ensureTaskChatForMembers,
  sendTaskChatMessage,
} from "./task-group-service";
import { getProjectDetail, ProjectError } from "./project-service";
import type { TaskPushRow } from "./wecom-group-push-service";

type FetchLike = typeof fetch;

export type AppMessageResult = {
  userid: string;
  ok: boolean;
  error: string;
};

export type MainChatMode = "group" | "per_member" | "skipped";

export type TaskChatPushResult = {
  sent: boolean;
  chatId: string;
  reason?: string;
};

export type ProjectPushOutcome = {
  mainChatMode: MainChatMode;
  appResults: AppMessageResult[];
  taskChat: TaskChatPushResult;
  skippedReasons: string[];
  linkUrl: string;
};

function text(value: unknown) {
  return String(value ?? "").trim();
}

export function buildProjectAppMessage(
  task: Pick<
    TaskPushRow,
    | "name"
    | "brand"
    | "quantity"
    | "due_at"
    | "task_type"
    | "platform"
    | "content_format"
    | "share_token"
  >,
  portalUrl: string,
): string {
  const portal = text(portalUrl).replace(/\/$/, "");
  const claimUrl =
    portal && task.share_token ? `${portal}/?task=${task.share_token}` : "";
  const formatLabel = task.content_format === "video" ? "视频" : "图文";
  return [
    `【项目任务】${task.name}`,
    `品牌：${task.brand}｜数量：${task.quantity} 份｜截止：${task.due_at}`,
    `平台：${task.platform}｜形式：${formatLabel}`,
    "请把任务转发到你负责的项目任务群，并跟进群内成员领取与发布。",
    claimUrl ? `领取链接：${claimUrl}` : "领取链接生成失败，请联系管理员",
  ].join("\n");
}

const TASK_CHAT_SKIP_REASONS: Record<string, string> = {
  no_task: "任务不存在",
  no_owner: "任务与项目都未填负责人",
  not_enough_members: "任务群成员不足 2 人",
  no_credentials: "企业微信未配置",
};

export async function pushProjectTask(
  db: DatabaseClient,
  params: {
    taskId: unknown;
    sendMainGroup?: unknown;
    sendGroupChats?: unknown;
    text?: unknown;
  },
  config: WecomConfig,
  fetchImpl: FetchLike = fetch,
): Promise<ProjectPushOutcome> {
  const taskId = text(params.taskId);
  if (!taskId) throw new ProjectError("缺少 taskId");
  const sendMainGroup = params.sendMainGroup !== false;
  const sendGroupChats = params.sendGroupChats !== false;
  if (!sendMainGroup && !sendGroupChats) {
    throw new ProjectError("请至少选择一个发送目标（项目总群或任务群）");
  }

  const task = await db
    .prepare(
      `SELECT id, name, brand, quantity, due_at, task_type, platform,
              content_format, share_token, project_id
       FROM tasks WHERE id = ?`,
    )
    .bind(taskId)
    .first<TaskPushRow & { project_id: string }>();
  if (!task) throw new ProjectError("任务不存在", 404);
  if (!text(task.project_id)) {
    throw new ProjectError("该任务未挂项目，请先在任务中心关联项目");
  }

  const detail = await getProjectDetail(db, task.project_id);
  const portalUrl = text(getRuntimeEnv().KOC_PORTAL_URL);
  const fallback = buildProjectAppMessage(task, portalUrl);
  const message = text(params.text) || fallback;

  const skippedReasons: string[] = [];
  const appResults: AppMessageResult[] = [];
  let mainChatMode: MainChatMode = "skipped";

  const sendPerMember = async () => {
    const members = detail.project.mainGroupMemberIds;
    if (members.length === 0) {
      skippedReasons.push("项目总群未建且未配置成员");
      return;
    }
    for (const userid of members) {
      try {
        await sendWecomAppMessage([userid], message, config, fetchImpl);
        appResults.push({ userid, ok: true, error: "" });
      } catch (error) {
        appResults.push({
          userid,
          ok: false,
          error: error instanceof Error ? error.message : "发送失败",
        });
      }
    }
    mainChatMode = "per_member";
  };

  if (sendMainGroup) {
    if (detail.project.mainChatId) {
      try {
        await sendAppChatMessage(
          config,
          { chatid: detail.project.mainChatId, text: message },
          fetchImpl,
        );
        mainChatMode = "group";
      } catch (error) {
        skippedReasons.push(
          `项目总群群发失败（${
            error instanceof Error ? error.message : "未知错误"
          }），已降级逐人私信`,
        );
        await sendPerMember();
      }
    } else {
      skippedReasons.push("项目总群未建，已逐人私信");
      await sendPerMember();
    }
  }

  let taskChat: TaskChatPushResult = { sent: false, chatId: "" };
  if (sendGroupChats) {
    const ensure = await ensureTaskChatForMembers(db, { taskId }, config, fetchImpl);
    if (ensure.chatId) {
      const sent = await sendTaskChatMessage(db, taskId, message, config, fetchImpl);
      taskChat = sent
        ? { sent: true, chatId: ensure.chatId }
        : { sent: false, chatId: ensure.chatId, reason: "消息发送失败" };
      if (!sent) skippedReasons.push("任务群消息发送失败");
    } else {
      const reason =
        TASK_CHAT_SKIP_REASONS[ensure.reason ?? ""] ?? "任务群暂不可用";
      taskChat = { sent: false, chatId: "", reason };
      skippedReasons.push(`任务群未发送：${reason}`);
    }
  }

  const linkUrl =
    task.share_token && portalUrl
      ? `${portalUrl.replace(/\/$/, "")}/?task=${task.share_token}`
      : "";

  return {
    mainChatMode,
    appResults,
    taskChat,
    skippedReasons,
    linkUrl,
  };
}

export { WecomClientError };