import fs from "node:fs";
import path from "node:path";
import type { OpenClawPluginApi } from "openclaw/plugin-sdk";
import { closeDiscussion, createDiscussion, getDiscussion, isDiscussionClosed, markDiscussionIdleReminderSent, type DiscussionMetadata } from "./discussion-state.js";
import {
  buildDiscussionClosedMessage,
  buildDiscussionIdleReminderMessage,
  buildDiscussionKickoffMessage,
  buildDiscussionOriginCallbackMessage,
} from "./discussion-messages.js";
import { sendModeratorMessage } from "./moderator-discord.js";

type DiscussionServiceDeps = {
  api: OpenClawPluginApi;
  moderatorBotToken?: string;
  moderatorUserId?: string;
  workspaceRoot?: string;
  forceNoReplyForSession: (sessionKey: string) => void;
  getDiscussionSessionKeys?: (channelId: string) => string[];
};

export function createDiscussionService(deps: DiscussionServiceDeps) {
  const defaultWorkspaceRoot = path.resolve(deps.workspaceRoot || process.cwd());

  async function initDiscussion(params: {
    discussionChannelId: string;
    originChannelId: string;
    initiatorAgentId: string;
    initiatorSessionId: string;
    initiatorWorkspaceRoot?: string;
    discussGuide: string;
  }): Promise<DiscussionMetadata> {
    const metadata = createDiscussion({
      mode: "discussion",
      discussionChannelId: params.discussionChannelId,
      originChannelId: params.originChannelId,
      initiatorAgentId: params.initiatorAgentId,
      initiatorSessionId: params.initiatorSessionId,
      initiatorWorkspaceRoot: params.initiatorWorkspaceRoot,
      discussGuide: params.discussGuide,
      status: "active",
      createdAt: new Date().toISOString(),
    });

    if (deps.moderatorBotToken) {
      const result = await sendModeratorMessage(
        deps.moderatorBotToken,
        params.discussionChannelId,
        buildDiscussionKickoffMessage(params.discussGuide),
        deps.api.logger,
      );
      if (!result.ok) {
        deps.api.logger.warn(`dirigent: discussion kickoff message failed channel=${params.discussionChannelId} error=${result.error}`);
      }
    }

    return metadata;
  }

  async function maybeSendIdleReminder(channelId: string): Promise<void> {
    const metadata = getDiscussion(channelId);
    if (!metadata || metadata.status !== "active" || metadata.idleReminderSent) return;
    markDiscussionIdleReminderSent(channelId);
    if (deps.moderatorBotToken) {
      const result = await sendModeratorMessage(
        deps.moderatorBotToken,
        channelId,
        buildDiscussionIdleReminderMessage(),
        deps.api.logger,
      );
      if (!result.ok) {
        deps.api.logger.warn(`dirigent: discussion idle reminder failed channel=${channelId} error=${result.error}`);
      }
    }
  }

  function validateSummaryPath(summaryPath: string, workspaceRoot?: string): string {
    if (!summaryPath || !summaryPath.trim()) throw new Error("summaryPath is required");

    const effectiveWorkspaceRoot = path.resolve(workspaceRoot || defaultWorkspaceRoot);
    const resolved = path.resolve(effectiveWorkspaceRoot, summaryPath);
    const relative = path.relative(effectiveWorkspaceRoot, resolved);
    if (relative.startsWith("..") || path.isAbsolute(relative)) {
      throw new Error("summaryPath must stay inside the initiator workspace");
    }

    const real = fs.realpathSync.native(resolved);
    const realWorkspace = fs.realpathSync.native(effectiveWorkspaceRoot);
    const realRelative = path.relative(realWorkspace, real);
    if (realRelative.startsWith("..") || path.isAbsolute(realRelative)) {
      throw new Error("summaryPath resolves outside the initiator workspace");
    }

    const stat = fs.statSync(real);
    if (!stat.isFile()) throw new Error("summaryPath must point to a file");
    return real;
  }

  async function handleCallback(params: {
    channelId: string;
    summaryPath: string;
    callerAgentId?: string;
    callerSessionKey?: string;
  }): Promise<{ ok: true; summaryPath: string; discussion: DiscussionMetadata }> {
    const metadata = getDiscussion(params.channelId);
    if (!metadata) throw new Error("current channel is not a discussion channel");
    if (metadata.status !== "active" || isDiscussionClosed(params.channelId)) throw new Error("discussion is already closed");
    if (!params.callerSessionKey || params.callerSessionKey !== metadata.initiatorSessionId) {
      throw new Error("only the discussion initiator session may call discuss-callback");
    }
    if (params.callerAgentId && params.callerAgentId !== metadata.initiatorAgentId) {
      throw new Error("only the discussion initiator agent may call discuss-callback");
    }

    const realPath = validateSummaryPath(params.summaryPath, metadata.initiatorWorkspaceRoot);
    const closed = closeDiscussion(params.channelId, realPath);
    if (!closed) throw new Error("failed to close discussion");

    const discussionSessionKeys = new Set<string>([
      metadata.initiatorSessionId,
      ...(deps.getDiscussionSessionKeys?.(metadata.discussionChannelId) || []),
    ]);
    for (const sessionKey of discussionSessionKeys) {
      if (sessionKey) deps.forceNoReplyForSession(sessionKey);
    }

    if (deps.moderatorBotToken) {
      const result = await sendModeratorMessage(
        deps.moderatorBotToken,
        metadata.originChannelId,
        buildDiscussionOriginCallbackMessage(realPath, metadata.discussionChannelId),
        deps.api.logger,
      );
      if (!result.ok) {
        deps.api.logger.warn(
          `dirigent: discussion origin callback notification failed originChannel=${metadata.originChannelId} error=${result.error}`,
        );
      }
    }

    return { ok: true, summaryPath: realPath, discussion: closed };
  }

  async function maybeReplyClosedChannel(channelId: string, senderId?: string): Promise<boolean> {
    const metadata = getDiscussion(channelId);
    if (!metadata || metadata.status !== "closed") return false;
    if (deps.moderatorUserId && senderId && senderId === deps.moderatorUserId) return true;
    if (!deps.moderatorBotToken) return true;
    const result = await sendModeratorMessage(deps.moderatorBotToken, channelId, buildDiscussionClosedMessage(), deps.api.logger);
    if (!result.ok) {
      deps.api.logger.warn(`dirigent: discussion closed reply failed channel=${channelId} error=${result.error}`);
    }
    return true;
  }

  return {
    initDiscussion,
    getDiscussion,
    isClosedDiscussion(channelId: string): boolean {
      return isDiscussionClosed(channelId);
    },
    maybeSendIdleReminder,
    maybeReplyClosedChannel,
    handleCallback,
  };
}