import EventEmitter from "events";
import { withLoader } from "../utils/loader";
import {
  getProfiles,
  getQueueItems,
  getRecords,
  getRepos,
} from "../api/atproto";
import { database } from "../services/db";
import { ToolsOzoneModerationDefs } from "@atproto/api";
import {
  transformRecordViewToRecord,
  transformRepoViewToRepo,
  transformProfileViewToProfile,
  transformStatusToSubject,
} from "../services/subject/transformers";
import { chunkArray } from "@atproto/common";
import { RecordRow } from "../schemas/record";
import { RepoRow } from "../schemas/repo";
import { SubjectRow } from "../schemas/subject";

export const fetchQueueItems = async (options: {
  count: number;
  cursor?: string;
  reviewState?: string;
  takendown?: boolean;
}) => {
  const emitter = new EventEmitter();
  const subjects = await withLoader(
    `Fetching queue items...`,
    async (updateMessage) => {
      emitter.on("update", ({ nextCursor, subjectCount, maxCount }) => {
        updateMessage(
          `Fetched page with cursor: ${nextCursor}, total subjects: ${subjectCount} out of ${maxCount}`
        );
      });

      const { cursor, subjectStatuses } = await getQueueItems(
        {
          maxCount: options.count ? Number(options.count) : undefined,
          reviewState: options.reviewState,
          takendown: options.takendown,
          cursor: options.cursor,
        },
        emitter
      );
      updateMessage(
        `Fetched ${subjectStatuses.length} queue items. Cursor: ${cursor}`
      );
      return subjectStatuses;
    }
  );

  return subjects;
};

export const saveQueueItems = async (
  subjects: ToolsOzoneModerationDefs.SubjectStatusView[]
) => {
  await withLoader(
    `Storing ${subjects.length} queue items...`,
    async (updateMessage) => {
      if (subjects.length === 0) {
        updateMessage("No queue items to store");
        throw new Error("No queue items to store");
      }
      for (const chunk of chunkArray(subjects, 500)) {
        await database.insertSubjects(chunk.map(transformStatusToSubject));
        updateMessage(
          `Stored ${chunk.length} out of ${subjects.length} queue items in local database`
        );
      }
      updateMessage(`Stored ${subjects.length} queue items in local database`);
    }
  );
};

export const fetchReposForSubjects = async () => {
  const emitter = new EventEmitter();
  const subjects = await withLoader(
    `Fetching repos for subjects...`,
    async (updateMessage) => {
      emitter.on("update", ({ total, repoCount }) => {
        updateMessage(`Fetched ${repoCount} repos out of ${total}`);
      });

      const dids = await database.getMissingRepoDids();
      updateMessage(`Found ${dids.length} missing repos to be fetched`);

      if (dids.length === 0) {
        return;
      }

      const repos = await getRepos({ dids }, emitter);
      updateMessage(
        `Fetched ${repos.length} repos. Saving in local database now`
      );

      for (const chunk of chunkArray(repos, 500)) {
        await database.saveRepos(chunk.map(transformRepoViewToRepo));
        updateMessage(
          `Saved ${chunk.length} out of ${repos.length} repos in local database now`
        );
      }

      updateMessage(`Saved ${repos.length} repos in local database`);
      return;
    }
  );

  return subjects;
};

export const fetchProfilesForSubjects = async () => {
  const emitter = new EventEmitter();
  const subjects = await withLoader(
    `Fetching profiles for subjects...`,
    async (updateMessage) => {
      emitter.on("update", ({ total, profileCount }) => {
        updateMessage(`Fetched ${profileCount} profiles out of ${total}`);
      });

      const dids = await database.getMissingProfileDids();
      updateMessage(`Found ${dids.length} profiles to be fetched`);

      if (dids.length === 0) {
        return;
      }

      const profiles = await getProfiles({ dids }, emitter);
      updateMessage(
        `Fetched ${profiles.length} profiles. Saving in local database now`
      );

      for (const chunk of chunkArray(profiles, 500)) {
        await database.saveProfiles(chunk.map(transformProfileViewToProfile));
        updateMessage(
          `Saved ${chunk.length} out of ${profiles.length} profiles in local database now`
        );
      }

      updateMessage(`Saved ${profiles.length} profiles in local database`);
      return;
    }
  );

  return subjects;
};

export const fetchRecordsForSubjects = async () => {
  const emitter = new EventEmitter();
  const subjects = await withLoader(
    `Fetching records for subjects...`,
    async (updateMessage) => {
      emitter.on("update", ({ total, recordCount }) => {
        updateMessage(`Fetched ${recordCount} records out of ${total}`);
      });

      const uris = await database.getMissingRecordUris();
      updateMessage(`Found ${uris.length} missing records to be fetched`);

      if (uris.length === 0) {
        return;
      }
      const records = await getRecords({ uris }, emitter);
      updateMessage(
        `Fetched ${records.length} records. Saving in local database now`
      );

      for (const chunk of chunkArray(records, 500)) {
        await database.saveRecords(chunk.map(transformRecordViewToRecord));
        updateMessage(
          `Saved ${chunk.length} out of ${records.length} records in local database`
        );
      }

      updateMessage(`Saved ${records.length} records in local database`);
      return;
    }
  );

  return subjects;
};

function looksLikeRegex(str: string) {
  // Check for common regex metacharacters
  const regexChars = /[.*+?^${}()|[\]\\]/;
  return regexChars.test(str);
}
function smartMatch(x: string, y: string) {
  if (looksLikeRegex(x)) {
    try {
      const regex = new RegExp(x);
      return regex.test(y);
    } catch (error) {
      // If regex is invalid, fall back to literal match
      return y.includes(x);
    }
  } else {
    // Treat as literal string
    return y.includes(x);
  }
}
export const processSubjects = async (options: {
  type?: string;
  cursor?: string;
  count?: number;
  bio?: string;
  keyword?: string;
  riskScore?: number;
  columns?: string;
  takendown?: boolean;
  lastCountry?: string[];
  email?: string;
}) => {
  let subjects = await database.listSubjects({
    takendown: options.takendown,
    subjectType: options.type,
    cursor: options.cursor,
    limit: options.count,
  });

  if (options.bio || options.keyword) {
    const keyword = `${options.bio || options.keyword}`.toLowerCase();
    const keywords = keyword
      .split("||")
      .map((k) => k.trim())
      .filter(Boolean);

    subjects = subjects.filter((subject) => {
      const { profile } = subject;
      if (!profile?.description) return false;
      const desc = profile.description.toLowerCase();
      if (keywords.length === 1) {
        return desc.includes(keyword);
      }
      return keywords.some((k) => desc.includes(k));
    });
  }

  if (options.email) {
    const keyword = options.email.toLowerCase();

    subjects = subjects.filter((subject) => {
      const { email } = subject;
      if (!email) return false;
      return smartMatch(keyword, email.toLowerCase());
    });
  }

  if (options.keyword) {
    const keyword = options.keyword.toLowerCase();
    const keywords = keyword
      .split("||")
      .map((k) => k.trim())
      .filter(Boolean);

    subjects = subjects.filter((subject) => {
      const recordValue = JSON.parse(subject.value || "{}");
      const text = recordValue.text?.toLowerCase();
      if (!text) return false;
      if (keywords.length === 1) {
        return text.includes(keyword);
      }
      return keywords.some((k) => text.includes(k));
    });
  }

  if (options.riskScore) {
    subjects = subjects.filter((subject) => {
      if (!options.riskScore) return;
      const hcap = subject.threatSignatures || [];
      const riskScore = hcap.find(
        (h: Record<string, unknown>) => h.property === "riskScore"
      )?.value;
      return riskScore && riskScore > options.riskScore;
    });
  }

  if (options.lastCountry?.length) {
    const countriesToMatch = options.lastCountry.map((c) => c.toLowerCase());
    subjects = subjects.filter((subject) => {
      const hcap = subject.threatSignatures || [];
      const lastCountry = hcap.find(
        (h: Record<string, unknown>) => h.property === "lastSigninCountry"
      )?.value;
      if (!lastCountry) return false;
      return countriesToMatch.includes(lastCountry.toLowerCase());
    });
  }

  return subjects.map((s) =>
    filterSubjectColumns(s, options.columns?.split(","))
  );
};

export const filterSubjectColumns = (
  subject: SubjectRow & RepoRow & RecordRow,
  columns?: string[]
): Record<string, any> => {
  if (!columns) return subject;
  const data: Record<string, any> = {};
  columns.forEach((column) => {
    if (column in subject) {
      // @ts-ignore
      data[column] = subject[column] as any;
    }
  });
  return data;
};