import { prisma } from '@/services/database';
import { resolveCollaborator } from '@/services/auth';
import { getTeamMemberIdsForAdminTeams } from '@/services/teams';
import { createSessionPermissionChecks } from '@/services/session-permissions';
import { createShareAndEventHandlers } from '@/services/session-share-events';
import {
  mergeSessionsByUserId,
  fetchTeamCollaboratorSessions,
  getSessionByIdGeneric,
} from '@/services/session-queries';
import type { SwotCategory, ShareRole } from '@prisma/client';

const sessionInclude = {
  user: { select: { id: true, name: true, email: true } },
  shares: { include: { user: { select: { id: true, name: true, email: true } } } },
  _count: { select: { items: true, actions: true } },
};

// ============================================
// Session CRUD
// ============================================

export async function getSessionsByUserId(userId: string) {
  return mergeSessionsByUserId(
    (uid) =>
      prisma.session.findMany({
        where: { userId: uid },
        include: sessionInclude,
        orderBy: { updatedAt: 'desc' },
      }),
    (uid) =>
      prisma.sessionShare.findMany({
        where: { userId: uid },
        include: { session: { include: sessionInclude } },
      }),
    userId,
    (s) => resolveCollaborator(s.collaborator).then((r) => ({ resolvedCollaborator: r }))
  );
}

/** Sessions owned by team members (where user is team admin) that are NOT shared with the user. */
export async function getTeamCollaboratorSessionsForAdmin(userId: string) {
  return fetchTeamCollaboratorSessions(
    (teamMemberIds, uid) =>
      prisma.session.findMany({
        where: { userId: { in: teamMemberIds }, shares: { none: { userId: uid } } },
        include: sessionInclude,
        orderBy: { updatedAt: 'desc' },
      }),
    getTeamMemberIdsForAdminTeams,
    userId,
    (s) => resolveCollaborator(s.collaborator).then((r) => ({ resolvedCollaborator: r }))
  );
}

const sessionByIdInclude = {
  user: { select: { id: true, name: true, email: true } },
  items: { orderBy: { order: 'asc' } as const },
  actions: {
    include: { links: { include: { swotItem: true } } },
    orderBy: { createdAt: 'asc' } as const,
  },
  shares: { include: { user: { select: { id: true, name: true, email: true } } } },
};

export async function getSessionById(sessionId: string, userId: string) {
  return getSessionByIdGeneric(
    sessionId,
    userId,
    (sid, uid) =>
      prisma.session.findFirst({
        where: { id: sid, OR: [{ userId: uid }, { shares: { some: { userId: uid } } }] },
        include: sessionByIdInclude,
      }),
    (sid) => prisma.session.findUnique({ where: { id: sid }, include: sessionByIdInclude }),
    (s) => resolveCollaborator(s.collaborator).then((r) => ({ resolvedCollaborator: r }))
  );
}

const sessionPermissions = createSessionPermissionChecks(prisma.session);

const sessionShareEvents = createShareAndEventHandlers<
  | 'ITEM_CREATED'
  | 'ITEM_UPDATED'
  | 'ITEM_DELETED'
  | 'ITEM_MOVED'
  | 'ACTION_CREATED'
  | 'ACTION_UPDATED'
  | 'ACTION_DELETED'
  | 'SESSION_UPDATED'
>(prisma.session, prisma.sessionShare, prisma.sessionEvent, sessionPermissions.canAccess);

export const canAccessSession = sessionPermissions.canAccess;
export const canEditSession = sessionPermissions.canEdit;
export const canDeleteSession = sessionPermissions.canDelete;

export async function createSession(userId: string, data: { title: string; collaborator: string }) {
  return prisma.session.create({
    data: {
      ...data,
      userId,
    },
  });
}

export async function updateSession(
  sessionId: string,
  userId: string,
  data: { title?: string; collaborator?: string }
) {
  if (!(await canEditSession(sessionId, userId))) {
    return { count: 0 };
  }
  return prisma.session.updateMany({
    where: { id: sessionId },
    data,
  });
}

export async function deleteSession(sessionId: string, userId: string) {
  if (!(await canDeleteSession(sessionId, userId))) {
    return { count: 0 };
  }
  return prisma.session.deleteMany({
    where: { id: sessionId },
  });
}

// ============================================
// SWOT Items CRUD
// ============================================

export async function createSwotItem(
  sessionId: string,
  data: { content: string; category: SwotCategory }
) {
  // Get max order for this category
  const maxOrder = await prisma.swotItem.aggregate({
    where: { sessionId, category: data.category },
    _max: { order: true },
  });

  return prisma.swotItem.create({
    data: {
      ...data,
      sessionId,
      order: (maxOrder._max.order ?? -1) + 1,
    },
  });
}

export async function updateSwotItem(
  itemId: string,
  data: { content?: string; category?: SwotCategory; order?: number }
) {
  return prisma.swotItem.update({
    where: { id: itemId },
    data,
  });
}

export async function deleteSwotItem(itemId: string) {
  return prisma.swotItem.delete({
    where: { id: itemId },
  });
}

export async function duplicateSwotItem(itemId: string) {
  const original = await prisma.swotItem.findUnique({
    where: { id: itemId },
  });

  if (!original) {
    throw new Error('Item not found');
  }

  // Get max order for this category
  const maxOrder = await prisma.swotItem.aggregate({
    where: { sessionId: original.sessionId, category: original.category },
    _max: { order: true },
  });

  return prisma.swotItem.create({
    data: {
      content: original.content,
      category: original.category,
      sessionId: original.sessionId,
      order: (maxOrder._max.order ?? -1) + 1,
    },
  });
}

export async function reorderSwotItems(
  sessionId: string,
  category: SwotCategory,
  itemIds: string[]
) {
  const updates = itemIds.map((id, index) =>
    prisma.swotItem.update({
      where: { id },
      data: { order: index },
    })
  );

  return prisma.$transaction(updates);
}

export async function moveSwotItem(itemId: string, newCategory: SwotCategory, newOrder: number) {
  return prisma.swotItem.update({
    where: { id: itemId },
    data: {
      category: newCategory,
      order: newOrder,
    },
  });
}

// ============================================
// Actions CRUD
// ============================================

export async function createAction(
  sessionId: string,
  data: {
    title: string;
    description?: string;
    priority?: number;
    linkedItemIds: string[];
  }
) {
  return prisma.action.create({
    data: {
      title: data.title,
      description: data.description,
      priority: data.priority ?? 0,
      sessionId,
      links: {
        create: data.linkedItemIds.map((swotItemId) => ({
          swotItemId,
        })),
      },
    },
    include: {
      links: {
        include: {
          swotItem: true,
        },
      },
    },
  });
}

export async function updateAction(
  actionId: string,
  data: {
    title?: string;
    description?: string;
    priority?: number;
    status?: string;
    dueDate?: Date | null;
    linkedItemIds?: string[];
  }
) {
  const { linkedItemIds, ...updateData } = data;

  // If linkedItemIds is provided, update the links
  if (linkedItemIds !== undefined) {
    // Delete all existing links
    await prisma.actionLink.deleteMany({
      where: { actionId },
    });

    // Create new links
    if (linkedItemIds.length > 0) {
      await prisma.actionLink.createMany({
        data: linkedItemIds.map((swotItemId) => ({
          actionId,
          swotItemId,
        })),
      });
    }
  }

  return prisma.action.update({
    where: { id: actionId },
    data: updateData,
    include: {
      links: {
        include: {
          swotItem: true,
        },
      },
    },
  });
}

export async function deleteAction(actionId: string) {
  return prisma.action.delete({
    where: { id: actionId },
  });
}

export async function linkItemToAction(actionId: string, swotItemId: string) {
  return prisma.actionLink.create({
    data: {
      actionId,
      swotItemId,
    },
  });
}

export async function unlinkItemFromAction(actionId: string, swotItemId: string) {
  return prisma.actionLink.deleteMany({
    where: {
      actionId,
      swotItemId,
    },
  });
}

// ============================================
// Session Sharing
// ============================================

export const shareSession = sessionShareEvents.share;
export const removeShare = sessionShareEvents.removeShare;
export const getSessionShares = sessionShareEvents.getShares;

// ============================================
// Session Events (for real-time sync)
// ============================================

export type SessionEventType =
  | 'ITEM_CREATED'
  | 'ITEM_UPDATED'
  | 'ITEM_DELETED'
  | 'ITEM_MOVED'
  | 'ACTION_CREATED'
  | 'ACTION_UPDATED'
  | 'ACTION_DELETED'
  | 'SESSION_UPDATED';

export const createSessionEvent = sessionShareEvents.createEvent;
export const getSessionEvents = sessionShareEvents.getEvents;
export const getLatestEventTimestamp = sessionShareEvents.getLatestEventTimestamp;