import { BadRequestException, Injectable, Logger, NotFoundException, UnauthorizedException } from '@nestjs/common';
import { PrismaService } from '../../prisma/prisma.service';
import { AuditService } from '../audit/audit.service';
import { AuditAction } from '../audit/audit.types';
import { ConsentScope, MemberGroupSummary, MemberOptOutReason, MemberProfile, OptInRequest, OptOutRequest } from '@tower/types';
import { ConsentStatus, MemberOptOutReason as MemberOptOutReasonEnum } from '@prisma/client';

@Injectable()
export class MyService {
  private readonly logger = new Logger(MyService.name);

  constructor(
    private readonly prisma: PrismaService,
    private readonly audit: AuditService,
  ) {}

  async getProfile(userId: string, tenantId: string): Promise<MemberProfile> {
    const user = await this.prisma.towerUser.findFirst({ where: { id: userId, tenantId } });
    if (!user) throw new NotFoundException('User not found');
    return {
      id: user.id,
      tenantId: user.tenantId,
      jid: user.jid,
      displayName: user.displayName,
      createdAt: user.createdAt.toISOString(),
    };
  }

  async listGroups(userId: string, tenantId: string): Promise<MemberGroupSummary[]> {
    const consents = await this.prisma.consentRecord.findMany({
      where: { userId, tenantId },
      include: { group: true },
    });
    return consents.map((c) => ({
      id: c.group.id,
      name: c.group.name,
      tenantId: c.tenantId,
      scopes: c.scopes as ConsentScope[],
      retentionDays: c.retentionDays,
      policyVersion: c.policyVersion,
      consentStatus: c.status as ConsentStatus,
      joinedAt: c.effectiveAt.toISOString(),
    }));
  }

  async getGroup(userId: string, tenantId: string, groupId: string): Promise<MemberGroupSummary> {
    const consent = await this.prisma.consentRecord.findFirst({
      where: { userId, tenantId, groupId },
      include: { group: true },
    });
    if (!consent) throw new NotFoundException('Not a member of this group');
    return {
      id: consent.group.id,
      name: consent.group.name,
      tenantId: consent.tenantId,
      scopes: consent.scopes as ConsentScope[],
      retentionDays: consent.retentionDays,
      policyVersion: consent.policyVersion,
      consentStatus: consent.status as ConsentStatus,
      joinedAt: consent.effectiveAt.toISOString(),
    };
  }

  async optOut(
    userId: string,
    tenantId: string,
    body: OptOutRequest,
  ): Promise<{ ok: true; revoked: number }> {
    const where = body.groupId
      ? { userId, tenantId, groupId: body.groupId }
      : { userId, tenantId };
    const consents = await this.prisma.consentRecord.findMany({ where });
    if (consents.length === 0) {
      throw new NotFoundException('No matching consent records');
    }
    const reason = body.reason ?? MemberOptOutReasonEnum.SELF_PORTAL;
    await this.prisma.$transaction(async (tx) => {
      for (const consent of consents) {
        if (body.scopes && body.scopes.length > 0) {
          const remaining = (consent.scopes as ConsentScope[]).filter((s) => !body.scopes!.includes(s));
          if (remaining.length === 0) {
            await tx.consentRecord.update({
              where: { id: consent.id },
              data: { status: ConsentStatus.REVOKED, revokedAt: new Date() },
            });
          } else {
            await tx.consentRecord.update({
              where: { id: consent.id },
              data: { scopes: remaining },
            });
          }
        } else {
          await tx.consentRecord.update({
            where: { id: consent.id },
            data: { status: ConsentStatus.REVOKED, revokedAt: new Date() },
          });
        }
        await tx.memberOptOut.create({
          data: {
            tenantId,
            userId,
            groupId: consent.groupId,
            reason,
            notes: body.notes ?? null,
          },
        });
      }
    });
    await this.audit.log({
      tenantId,
      action: AuditAction.MEMBER_OPT_OUT,
      resourceType: 'TowerUser',
      resourceId: userId,
      payload: { groupId: body.groupId, scopes: body.scopes, reason },
    });
    return { ok: true, revoked: consents.length };
  }

  async optIn(
    userId: string,
    tenantId: string,
    body: OptInRequest,
  ): Promise<{ ok: true; consentId: string }> {
    if (body.scopes.length === 0) {
      throw new BadRequestException('At least one scope is required');
    }
    const group = await this.prisma.group.findFirst({ where: { id: body.groupId, tenantId } });
    if (!group) throw new NotFoundException('Group not found in your tenant');

    const user = await this.prisma.towerUser.findFirst({ where: { id: userId, tenantId } });
    if (!user) throw new UnauthorizedException('User not found');

    const existing = await this.prisma.consentRecord.findFirst({
      where: { userId, tenantId, groupId: body.groupId },
    });

    let consent;
    if (existing) {
      consent = await this.prisma.consentRecord.update({
        where: { id: existing.id },
        data: {
          scopes: body.scopes,
          retentionDays: body.retentionDays ?? existing.retentionDays,
          status: ConsentStatus.GRANTED,
          revokedAt: null,
          effectiveAt: new Date(),
        },
      });
    } else {
      consent = await this.prisma.consentRecord.create({
        data: {
          tenantId,
          groupId: body.groupId,
          userId,
          scopes: body.scopes,
          retentionDays: body.retentionDays ?? 90,
          policyVersion: 'v1',
          status: ConsentStatus.GRANTED,
          proofEventId: 'self',
        },
      });
    }

    await this.audit.log({
      tenantId,
      action: AuditAction.MEMBER_OPT_IN,
      resourceType: 'TowerUser',
      resourceId: userId,
      payload: { groupId: body.groupId, scopes: body.scopes },
    });

    return { ok: true, consentId: consent.id };
  }

  async deleteAccount(userId: string, tenantId: string): Promise<{ ok: true }> {
    await this.prisma.$transaction(async (tx) => {
      await tx.consentRecord.deleteMany({ where: { userId, tenantId } });
      await tx.memberOptOut.deleteMany({ where: { userId, tenantId } });
      await tx.towerSession.deleteMany({ where: { userId } });
      await tx.towerUser.delete({ where: { id: userId } });
    });
    await this.audit.log({
      tenantId,
      action: AuditAction.MEMBER_DELETED,
      resourceType: 'TowerUser',
      resourceId: userId,
    });
    return { ok: true };
  }
}