import type {
  AdminDiagnosticsDto,
  BackupGuidanceDto,
  AdminPermissionOptionDto,
  AdminRoleDto,
  AdminRoleInput,
  AdminUserDto,
  AdminUserInput,
  SupportSnapshotDto,
  AuditEventDto,
  SupportLogEntryDto,
} from "@mrp/shared";

import { env } from "../../config/env.js";
import { paths } from "../../config/paths.js";
import { logAuditEvent } from "../../lib/audit.js";
import { hashPassword } from "../../lib/password.js";
import { prisma } from "../../lib/prisma.js";
import { getLatestStartupReport } from "../../lib/startup-state.js";
import { getSupportLogCount, listSupportLogs } from "../../lib/support-log.js";

function mapAuditEvent(record: {
  id: string;
  actorId: string | null;
  entityType: string;
  entityId: string | null;
  action: string;
  summary: string;
  metadataJson: string;
  createdAt: Date;
  actor: {
    firstName: string;
    lastName: string;
  } | null;
}): AuditEventDto {
  return {
    id: record.id,
    actorId: record.actorId,
    actorName: record.actor ? `${record.actor.firstName} ${record.actor.lastName}`.trim() : null,
    entityType: record.entityType,
    entityId: record.entityId,
    action: record.action,
    summary: record.summary,
    metadataJson: record.metadataJson,
    createdAt: record.createdAt.toISOString(),
  };
}

function mapSupportLogEntry(record: SupportLogEntryDto): SupportLogEntryDto {
  return {
    id: record.id,
    level: record.level,
    source: record.source,
    message: record.message,
    contextJson: record.contextJson,
    createdAt: record.createdAt,
  };
}

function mapRole(record: {
  id: string;
  name: string;
  description: string;
  createdAt: Date;
  updatedAt: Date;
  rolePermissions: Array<{
    permission: {
      key: string;
    };
  }>;
  _count: {
    userRoles: number;
  };
}): AdminRoleDto {
  return {
    id: record.id,
    name: record.name,
    description: record.description,
    permissionKeys: record.rolePermissions.map((rolePermission) => rolePermission.permission.key).sort(),
    userCount: record._count.userRoles,
    createdAt: record.createdAt.toISOString(),
    updatedAt: record.updatedAt.toISOString(),
  };
}

function mapUser(record: {
  id: string;
  email: string;
  firstName: string;
  lastName: string;
  isActive: boolean;
  createdAt: Date;
  updatedAt: Date;
  userRoles: Array<{
    role: {
      id: string;
      name: string;
      rolePermissions: Array<{
        permission: {
          key: string;
        };
      }>;
    };
  }>;
}): AdminUserDto {
  const permissionKeys = new Set<string>();
  for (const userRole of record.userRoles) {
    for (const rolePermission of userRole.role.rolePermissions) {
      permissionKeys.add(rolePermission.permission.key);
    }
  }

  return {
    id: record.id,
    email: record.email,
    firstName: record.firstName,
    lastName: record.lastName,
    isActive: record.isActive,
    roleIds: record.userRoles.map((userRole) => userRole.role.id),
    roleNames: record.userRoles.map((userRole) => userRole.role.name),
    permissionKeys: [...permissionKeys].sort(),
    createdAt: record.createdAt.toISOString(),
    updatedAt: record.updatedAt.toISOString(),
  };
}

async function validatePermissionKeys(permissionKeys: string[]) {
  const uniquePermissionKeys = [...new Set(permissionKeys)];
  const permissions = await prisma.permission.findMany({
    where: {
      key: {
        in: uniquePermissionKeys,
      },
    },
    select: {
      id: true,
      key: true,
    },
  });

  if (permissions.length !== uniquePermissionKeys.length) {
    return { ok: false as const, reason: "One or more selected permissions are invalid." };
  }

  return { ok: true as const, permissions };
}

async function validateRoleIds(roleIds: string[]) {
  const uniqueRoleIds = [...new Set(roleIds)];
  const roles = await prisma.role.findMany({
    where: {
      id: {
        in: uniqueRoleIds,
      },
    },
    select: {
      id: true,
      name: true,
    },
  });

  if (roles.length !== uniqueRoleIds.length) {
    return { ok: false as const, reason: "One or more selected roles are invalid." };
  }

  return { ok: true as const, roles };
}

export async function listAdminPermissions(): Promise<AdminPermissionOptionDto[]> {
  const permissions = await prisma.permission.findMany({
    orderBy: [{ key: "asc" }],
  });

  return permissions.map((permission) => ({
    key: permission.key,
    description: permission.description,
  }));
}

export async function listAdminRoles(): Promise<AdminRoleDto[]> {
  const roles = await prisma.role.findMany({
    include: {
      rolePermissions: {
        include: {
          permission: {
            select: {
              key: true,
            },
          },
        },
      },
      _count: {
        select: {
          userRoles: true,
        },
      },
    },
    orderBy: [{ name: "asc" }],
  });

  return roles.map(mapRole);
}

export async function createAdminRole(payload: AdminRoleInput, actorId?: string | null) {
  const validatedPermissions = await validatePermissionKeys(payload.permissionKeys);
  if (!validatedPermissions.ok) {
    return { ok: false as const, reason: validatedPermissions.reason };
  }

  const role = await prisma.role.create({
    data: {
      name: payload.name.trim(),
      description: payload.description,
      rolePermissions: {
        create: validatedPermissions.permissions.map((permission) => ({
          permissionId: permission.id,
        })),
      },
    },
    include: {
      rolePermissions: {
        include: {
          permission: {
            select: {
              key: true,
            },
          },
        },
      },
      _count: {
        select: {
          userRoles: true,
        },
      },
    },
  });

  await logAuditEvent({
    actorId,
    entityType: "role",
    entityId: role.id,
    action: "created",
    summary: `Created role ${role.name}.`,
    metadata: {
      name: role.name,
      permissionKeys: role.rolePermissions.map((rolePermission) => rolePermission.permission.key),
    },
  });

  return { ok: true as const, role: mapRole(role) };
}

export async function updateAdminRole(roleId: string, payload: AdminRoleInput, actorId?: string | null) {
  const existingRole = await prisma.role.findUnique({
    where: { id: roleId },
    select: { id: true, name: true },
  });

  if (!existingRole) {
    return { ok: false as const, reason: "Role was not found." };
  }

  const validatedPermissions = await validatePermissionKeys(payload.permissionKeys);
  if (!validatedPermissions.ok) {
    return { ok: false as const, reason: validatedPermissions.reason };
  }

  const role = await prisma.role.update({
    where: { id: roleId },
    data: {
      name: payload.name.trim(),
      description: payload.description,
      rolePermissions: {
        deleteMany: {},
        create: validatedPermissions.permissions.map((permission) => ({
          permissionId: permission.id,
        })),
      },
    },
    include: {
      rolePermissions: {
        include: {
          permission: {
            select: {
              key: true,
            },
          },
        },
      },
      _count: {
        select: {
          userRoles: true,
        },
      },
    },
  });

  await logAuditEvent({
    actorId,
    entityType: "role",
    entityId: role.id,
    action: "updated",
    summary: `Updated role ${role.name}.`,
    metadata: {
      previousName: existingRole.name,
      name: role.name,
      permissionKeys: role.rolePermissions.map((rolePermission) => rolePermission.permission.key),
    },
  });

  return { ok: true as const, role: mapRole(role) };
}

export async function listAdminUsers(): Promise<AdminUserDto[]> {
  const users = await prisma.user.findMany({
    include: {
      userRoles: {
        include: {
          role: {
            include: {
              rolePermissions: {
                include: {
                  permission: {
                    select: {
                      key: true,
                    },
                  },
                },
              },
            },
          },
        },
      },
    },
    orderBy: [{ firstName: "asc" }, { lastName: "asc" }, { email: "asc" }],
  });

  return users.map(mapUser);
}

export async function createAdminUser(payload: AdminUserInput, actorId?: string | null) {
  if (!payload.password || payload.password.trim().length < 8) {
    return { ok: false as const, reason: "A password with at least 8 characters is required for new users." };
  }

  const validatedRoles = await validateRoleIds(payload.roleIds);
  if (!validatedRoles.ok) {
    return { ok: false as const, reason: validatedRoles.reason };
  }

  const user = await prisma.user.create({
    data: {
      email: payload.email.trim().toLowerCase(),
      firstName: payload.firstName.trim(),
      lastName: payload.lastName.trim(),
      isActive: payload.isActive,
      passwordHash: await hashPassword(payload.password.trim()),
      userRoles: {
        create: validatedRoles.roles.map((role) => ({
          roleId: role.id,
          assignedBy: actorId ?? null,
        })),
      },
    },
    include: {
      userRoles: {
        include: {
          role: {
            include: {
              rolePermissions: {
                include: {
                  permission: {
                    select: {
                      key: true,
                    },
                  },
                },
              },
            },
          },
        },
      },
    },
  });

  await logAuditEvent({
    actorId,
    entityType: "user",
    entityId: user.id,
    action: "created",
    summary: `Created user account for ${user.email}.`,
    metadata: {
      email: user.email,
      isActive: user.isActive,
      roleNames: user.userRoles.map((userRole) => userRole.role.name),
    },
  });

  return { ok: true as const, user: mapUser(user) };
}

export async function updateAdminUser(userId: string, payload: AdminUserInput, actorId?: string | null) {
  const existingUser = await prisma.user.findUnique({
    where: { id: userId },
    select: {
      id: true,
      email: true,
    },
  });

  if (!existingUser) {
    return { ok: false as const, reason: "User was not found." };
  }

  const validatedRoles = await validateRoleIds(payload.roleIds);
  if (!validatedRoles.ok) {
    return { ok: false as const, reason: validatedRoles.reason };
  }

  const data = {
    email: payload.email.trim().toLowerCase(),
    firstName: payload.firstName.trim(),
    lastName: payload.lastName.trim(),
    isActive: payload.isActive,
    ...(payload.password?.trim()
      ? {
          passwordHash: await hashPassword(payload.password.trim()),
        }
      : {}),
    userRoles: {
      deleteMany: {},
      create: validatedRoles.roles.map((role) => ({
        roleId: role.id,
        assignedBy: actorId ?? null,
      })),
    },
  };

  const user = await prisma.user.update({
    where: { id: userId },
    data,
    include: {
      userRoles: {
        include: {
          role: {
            include: {
              rolePermissions: {
                include: {
                  permission: {
                    select: {
                      key: true,
                    },
                  },
                },
              },
            },
          },
        },
      },
    },
  });

  await logAuditEvent({
    actorId,
    entityType: "user",
    entityId: user.id,
    action: "updated",
    summary: `Updated user account for ${user.email}.`,
    metadata: {
      previousEmail: existingUser.email,
      email: user.email,
      isActive: user.isActive,
      roleNames: user.userRoles.map((userRole) => userRole.role.name),
      passwordReset: Boolean(payload.password?.trim()),
    },
  });

  return { ok: true as const, user: mapUser(user) };
}

export async function getAdminDiagnostics(): Promise<AdminDiagnosticsDto> {
  const startupReport = getLatestStartupReport();
  const recentSupportLogs = listSupportLogs(50);
  const [
    companyProfile,
    userCount,
    activeUserCount,
    roleCount,
    permissionCount,
    customerCount,
    vendorCount,
    inventoryItemCount,
    warehouseCount,
    workOrderCount,
    projectCount,
    purchaseOrderCount,
    salesQuoteCount,
    salesOrderCount,
    shipmentCount,
    attachmentCount,
    auditEventCount,
    recentAuditEvents,
  ] = await Promise.all([
    prisma.companyProfile.findFirst({ where: { isActive: true }, select: { id: true } }),
    prisma.user.count(),
    prisma.user.count({ where: { isActive: true } }),
    prisma.role.count(),
    prisma.permission.count(),
    prisma.customer.count(),
    prisma.vendor.count(),
    prisma.inventoryItem.count(),
    prisma.warehouse.count(),
    prisma.workOrder.count(),
    prisma.project.count(),
    prisma.purchaseOrder.count(),
    prisma.salesQuote.count(),
    prisma.salesOrder.count(),
    prisma.shipment.count(),
    prisma.fileAttachment.count(),
    prisma.auditEvent.count(),
    prisma.auditEvent.findMany({
      include: {
        actor: {
          select: {
            firstName: true,
            lastName: true,
          },
        },
      },
      orderBy: [{ createdAt: "desc" }],
      take: 25,
    }),
  ]);

  return {
    serverTime: new Date().toISOString(),
    nodeVersion: process.version,
    databaseUrl: env.DATABASE_URL,
    dataDir: paths.dataDir,
    uploadsDir: paths.uploadsDir,
    clientOrigin: env.CLIENT_ORIGIN,
    companyProfilePresent: Boolean(companyProfile),
    userCount,
    activeUserCount,
    roleCount,
    permissionCount,
    customerCount,
    vendorCount,
    inventoryItemCount,
    warehouseCount,
    workOrderCount,
    projectCount,
    purchaseOrderCount,
    salesDocumentCount: salesQuoteCount + salesOrderCount,
    shipmentCount,
    attachmentCount,
    auditEventCount,
    supportLogCount: getSupportLogCount(),
    startup: startupReport,
    recentAuditEvents: recentAuditEvents.map(mapAuditEvent),
    recentSupportLogs: recentSupportLogs.map(mapSupportLogEntry),
  };
}

export function getBackupGuidance(): BackupGuidanceDto {
  return {
    dataPath: paths.dataDir,
    databasePath: `${paths.prismaDir}/app.db`,
    uploadsPath: paths.uploadsDir,
    recommendedBackupTarget: "/mnt/user/backups/mrp-codex",
    backupSteps: [
      {
        id: "stop-app",
        label: "Stop writes before copying data",
        detail: "Stop the container or application process before copying the data directory so SQLite and attachments stay consistent.",
      },
      {
        id: "copy-data",
        label: "Back up the full data directory",
        detail: `Copy the full data directory at ${paths.dataDir}, not just the SQLite file, so uploads and attachments are preserved with the database.`,
      },
      {
        id: "retain-metadata",
        label: "Keep timestamps and structure",
        detail: "Preserve directory structure, filenames, and timestamps during backup so support recovery remains straightforward.",
      },
      {
        id: "record-build",
        label: "Record image/version context",
        detail: "Capture the deployed image tag or commit alongside the backup so schema and runtime expectations are clear during restore.",
      },
    ],
    restoreSteps: [
      {
        id: "stop-target",
        label: "Stop the target app before restore",
        detail: "Do not restore into a running instance. Stop the target container or process before replacing the data directory.",
      },
      {
        id: "replace-data",
        label: "Restore the full data directory",
        detail: `Replace the target data directory with the backed-up copy so ${paths.prismaDir}/app.db and uploads come back together.`,
      },
      {
        id: "start-and-migrate",
        label: "Start the app and let migrations run",
        detail: "Restart the application after restore and allow the normal startup migration flow to complete before validation.",
      },
      {
        id: "validate-core",
        label: "Validate login, files, and PDFs",
        detail: "Confirm admin login, attachment access, and PDF generation after restore to verify the operational surface is healthy.",
      },
    ],
    verificationChecklist: [
      {
        id: "backup-size-check",
        label: "Confirm backup contains data and uploads",
        detail: "Verify the backup archive or copied directory includes the SQLite database and uploads tree rather than only one of them.",
        evidence: "Directory listing or archive manifest showing prisma/app.db and uploads/ content.",
      },
      {
        id: "timestamp-check",
        label: "Check backup freshness",
        detail: "Confirm the backup timestamp matches the expected backup window and is newer than the last major data-entry period you need to protect.",
        evidence: "Backup timestamp recorded in your scheduler, NAS share, or copied folder metadata.",
      },
      {
        id: "snapshot-export",
        label: "Capture a support snapshot with the backup",
        detail: "Export the support snapshot from diagnostics when taking a formal backup so the runtime state and active-user footprint are recorded alongside it.",
        evidence: "JSON support snapshot stored with the backup set or support ticket.",
      },
      {
        id: "app-stop-check",
        label: "Verify writes were stopped before copy",
        detail: "Use a controlled maintenance stop or container stop before backup to reduce the chance of a partial SQLite copy.",
        evidence: "Maintenance log entry, Docker stop event, or operator note recorded with the backup.",
      },
    ],
    restoreDrillSteps: [
      {
        id: "prepare-drill-target",
        label: "Prepare isolated restore target",
        detail: "Restore into an isolated container or duplicate environment instead of the live production instance.",
        expectedOutcome: "A clean target environment is ready to receive the backed-up data directory without impacting production.",
      },
      {
        id: "load-backed-up-data",
        label: "Load the full backup set",
        detail: `Restore the full backed-up data directory so ${paths.prismaDir}/app.db and uploads are returned together.`,
        expectedOutcome: "The restore target contains both database and file assets with the original directory structure intact.",
      },
      {
        id: "boot-restored-app",
        label: "Start the restored application",
        detail: "Launch the restored app and allow startup validation plus migrations to complete normally.",
        expectedOutcome: "The application starts without startup-validation failures and the diagnostics page loads.",
      },
      {
        id: "run-functional-checks",
        label: "Run post-restore functional checks",
        detail: "Verify login, one attachment download, one PDF render, and one representative transactional detail page such as inventory, purchasing, or shipping.",
        expectedOutcome: "Core operational flows work in the restored environment and file/PDF dependencies remain valid.",
      },
      {
        id: "record-drill-results",
        label: "Record restore-drill results",
        detail: "Capture the drill date, backup source used, startup status, and any gaps discovered so future recovery work improves over time.",
        expectedOutcome: "A dated restore-drill record exists for support and disaster-recovery review.",
      },
    ],
  };
}

export async function getSupportSnapshot(): Promise<SupportSnapshotDto> {
  const diagnostics = await getAdminDiagnostics();
  const backupGuidance = getBackupGuidance();
  const [users, roles] = await Promise.all([
    prisma.user.findMany({
      where: { isActive: true },
      select: { email: true },
      orderBy: [{ email: "asc" }],
    }),
    prisma.role.count(),
  ]);

  return {
    generatedAt: new Date().toISOString(),
    diagnostics,
    userCount: diagnostics.userCount,
    roleCount: roles,
    activeUserEmails: users.map((user) => user.email),
    backupGuidance,
    recentSupportLogs: diagnostics.recentSupportLogs,
  };
}

export function getSupportLogs() {
  return listSupportLogs(100).map(mapSupportLogEntry);
}