"use server";

import config from "@payload-config";
import { getPayload } from "payload";
import { isPayloadUser } from "@/utils/access-control/isPayloadUser";
import { isSuperuser } from "@/utils/access-control/hasPermission";
import { emitGameEvent } from "@/utils/event-log/emit";
import { EventTypes } from "@/utils/event-log/eventTypes";
import {
  countGrantsByGrantor,
  findUserProfile,
  getGrantorAssignments,
  isRecipientEligible,
} from "@/lib/awards/grant";
import { cleanupDuplicateAwards, type CleanupResult } from "@/lib/awards/index";
import type { Assignment, Profile } from "@/payload-types";

interface ActionResult<T = undefined> {
  success: boolean;
  error?: string;
  data?: T;
}

async function authenticate() {
  const payloadConfig = await config;
  const payload = await getPayload({ config: payloadConfig });
  const { headers } = await import("next/headers");
  const hdrs = await headers();
  const { user } = await payload.auth({
    headers: hdrs,
    canSetHeaders: false,
  });

  if (!isPayloadUser(user)) {
    throw new Error("Unauthorized");
  }

  return { payload, user };
}

export interface GrantResult {
  recipientUserId: number;
  success: boolean;
  error?: string;
}

export async function grantAward(input: {
  recipientUserIds: number[];
  awardId: number;
  reason?: string;
}): Promise<ActionResult<{ results: GrantResult[]; granted: number; failed: number }>> {
  try {
    const { payload, user } = await authenticate();

    if (input.recipientUserIds.length === 0) {
      return { success: false, error: "No recipients selected." };
    }

    let award;
    try {
      award = await payload.findByID({
        collection: "awards",
        id: input.awardId,
        depth: 0,
        overrideAccess: true,
      });
    } catch {
      return { success: false, error: "Award not found." };
    }

    let grantorProfile: Profile | null = null;
    const superuser = await isSuperuser(payload, user);

    const isMedal = award.type === "medal";
    if (isMedal && !superuser) {
      return { success: false, error: "Only superusers can grant medals." };
    }

    let grantorAssignmentId: number | undefined;
    let scope: "same_command" | "whitelist" | "anyone" | null | undefined;
    let whitelist: (number | Assignment)[] | null | undefined;
    let remaining: number | null = null;

    if (!superuser && !isMedal) {
      const allowedTypes = award.grantConfig?.allowedGrantorAssignmentTypes ?? [];
      if (allowedTypes.length === 0) {
        return { success: false, error: "This award cannot be granted by leaders." };
      }

      const grantorAssignments = await getGrantorAssignments(
        payload,
        user.id as number,
        allowedTypes,
      );
      if (grantorAssignments.length === 0) {
        return { success: false, error: "You are not authorized to grant this award." };
      }
      grantorAssignmentId = grantorAssignments[0].id;
      scope = award.grantConfig?.recipientScope ?? "same_command";
      whitelist = award.grantConfig?.eligibleRecipientAssignments;

      const maxGrants = award.grantConfig?.maxGrantsPerGrantor ?? null;
      if (maxGrants) {
        grantorProfile = await findUserProfile(payload, user.id as number);
        if (!grantorProfile) {
          return { success: false, error: "You do not have a profile." };
        }
        const issued = await countGrantsByGrantor(payload, award.id, grantorProfile.id);
        remaining = maxGrants - issued;
        if (remaining <= 0) {
          return {
            success: false,
            error: "You have reached the maximum number of grants for this award.",
          };
        }
      }
    }

    if (!grantorProfile) {
      grantorProfile = await findUserProfile(payload, user.id as number);
    }
    if (!grantorProfile) {
      return { success: false, error: "You do not have a profile." };
    }

    const results: GrantResult[] = [];
    let granted = 0;
    let processed = 0;

    for (const recipientUserId of input.recipientUserIds) {
      if (remaining !== null && processed >= remaining) break;

      if (grantorAssignmentId !== undefined) {
        const eligible = await isRecipientEligible(
          payload,
          recipientUserId,
          scope,
          grantorAssignmentId,
          whitelist,
        );
        if (!eligible) {
          results.push({
            recipientUserId,
            success: false,
            error: "Recipient is not eligible for this award.",
          });
          processed += 1;
          continue;
        }
      }

      const recipientProfile = await findUserProfile(payload, recipientUserId);
      if (!recipientProfile) {
        results.push({
          recipientUserId,
          success: false,
          error: "Recipient does not have a profile.",
        });
        processed += 1;
        continue;
      }

      const progression = recipientProfile.progression;
      const currentAwards = progression?.awards ?? [];

      const alreadyHasAward = currentAwards.some((e) => {
        const id = typeof e.award === "number" ? e.award : e.award?.id;
        return id === award.id;
      });
      if (alreadyHasAward) {
        results.push({
          recipientUserId,
          success: false,
          error: "Recipient already has this award.",
        });
        processed += 1;
        continue;
      }

      await payload.update({
        collection: "profiles",
        id: recipientProfile.id,
        data: {
          progression: {
            ...progression,
            awards: [
              ...currentAwards,
              {
                award: award.id,
                awardedBy: grantorProfile.id,
                awardedAt: new Date().toISOString(),
                awardReason: input.reason ?? null,
              },
            ],
          },
        },
        overrideAccess: true,
      });

      await emitGameEvent(payload, {
        type: EventTypes.AwardGrant,
        message: `Granted "${award.name}" to recipient profile #${recipientProfile.id}`,
        actor: user.id,
        data: { awardId: award.id, grantorProfileId: grantorProfile.id },
      });

      results.push({ recipientUserId, success: true });
      granted += 1;
      processed += 1;
    }

    return {
      success: true,
      data: { results, granted, failed: results.length - granted },
    };
  } catch (e) {
    return {
      success: false,
      error: e instanceof Error ? e.message : "Unknown error",
    };
  }
}

export async function cleanupDuplicateAwardsAction(): Promise<
  ActionResult<CleanupResult>
> {
  try {
    const { payload, user } = await authenticate();
    const superuser = await isSuperuser(payload, user);
    if (!superuser) {
      return { success: false, error: "Only superusers can run award cleanup." };
    }
    const result = await cleanupDuplicateAwards(payload);
    return { success: true, data: result };
  } catch (e) {
    return {
      success: false,
      error: e instanceof Error ? e.message : "Unknown error",
    };
  }
}