import type { OpenCodeContext } from "../../../types/plugin";
import type { Session } from "@opencode-ai/sdk";
import type { SessionListArgs } from "./types";
import { buildSessionSummary, formatSessionList } from "../session-formatter";
import { log } from "../../../shared/logger";

function isAfterDate(session: Session, fromDate: string): boolean {
  const from = new Date(fromDate).getTime();
  return session.time.updated >= from;
}

function isBeforeDate(session: Session, toDate: string): boolean {
  const to = new Date(toDate).getTime();
  return session.time.updated <= to;
}

export async function handleSessionList(
  args: SessionListArgs,
  ctx: OpenCodeContext,
): Promise<string> {
  try {
    const directory = args.project_path ?? ctx.directory;
    const response = await ctx.client.session.list({ query: { directory } });
    const sessions: Session[] = response.data ?? [];

    let filtered = sessions.filter((s) => !s.parentID);

    if (args.from_date) {
      filtered = filtered.filter((s) => isAfterDate(s, args.from_date!));
    }

    if (args.to_date) {
      filtered = filtered.filter((s) => isBeforeDate(s, args.to_date!));
    }

    filtered.sort((a, b) => b.time.updated - a.time.updated);

    const MAX_DEFAULT_SESSIONS = 20;
    filtered =
      args.limit && args.limit > 0
        ? filtered.slice(0, args.limit)
        : filtered.slice(0, MAX_DEFAULT_SESSIONS);

    const summaryPromises = filtered.map(async (session) => {
      const msgResponse = await ctx.client.session.messages({ path: { id: session.id } });
      const messages = msgResponse.data ?? [];
      return buildSessionSummary(session.id, messages);
    });

    const summaries = await Promise.all(summaryPromises);
    return formatSessionList(summaries);
  } catch (e) {
    log("session_list error", e);
    return `Error: ${e instanceof Error ? e.message : String(e)}`;
  }
}