package libpod

import (
	"fmt"

	"github.com/containers/podman/v4/libpod/define"
	spec "github.com/opencontainers/runtime-spec/specs-go"
)

// Validate that the configuration of a container is valid.
func (c *Container) validate() error {
	imageIDSet := c.config.RootfsImageID != ""
	imageNameSet := c.config.RootfsImageName != ""
	rootfsSet := c.config.Rootfs != ""

	// If one of RootfsImageIDor RootfsImageName are set, both must be set.
	if (imageIDSet || imageNameSet) && !(imageIDSet && imageNameSet) {
		return fmt.Errorf("both RootfsImageName and RootfsImageID must be set if either is set: %w", define.ErrInvalidArg)
	}

	// Cannot set RootfsImageID and Rootfs at the same time
	if imageIDSet && rootfsSet {
		return fmt.Errorf("cannot set both an image ID and rootfs for a container: %w", define.ErrInvalidArg)
	}

	// Must set at least one of RootfsImageID or Rootfs
	if !(imageIDSet || rootfsSet) {
		return fmt.Errorf("must set root filesystem source to either image or rootfs: %w", define.ErrInvalidArg)
	}

	// A container cannot be marked as an infra and service container at
	// the same time.
	if c.IsInfra() && c.IsService() {
		return fmt.Errorf("cannot be infra and service container at the same time: %w", define.ErrInvalidArg)
	}

	// Cannot make a network namespace if we are joining another container's
	// network namespace
	if c.config.CreateNetNS && c.config.NetNsCtr != "" {
		return fmt.Errorf("cannot both create a network namespace and join another container's network namespace: %w", define.ErrInvalidArg)
	}

	if c.config.CgroupsMode == cgroupSplit && c.config.CgroupParent != "" {
		return fmt.Errorf("cannot specify --cgroup-mode=split with a cgroup-parent: %w", define.ErrInvalidArg)
	}

	// Not creating cgroups has a number of requirements, mostly related to
	// the PID namespace.
	if c.config.NoCgroups || c.config.CgroupsMode == "disabled" {
		if c.config.PIDNsCtr != "" {
			return fmt.Errorf("cannot join another container's PID namespace if not creating cgroups: %w", define.ErrInvalidArg)
		}

		if c.config.CgroupParent != "" {
			return fmt.Errorf("cannot set cgroup parent if not creating cgroups: %w", define.ErrInvalidArg)
		}

		// Ensure we have a PID namespace
		if c.config.Spec.Linux == nil {
			return fmt.Errorf("must provide Linux namespace configuration in OCI spec when using NoCgroups: %w", define.ErrInvalidArg)
		}
		foundPid := false
		for _, ns := range c.config.Spec.Linux.Namespaces {
			if ns.Type == spec.PIDNamespace {
				foundPid = true
				if ns.Path != "" {
					return fmt.Errorf("containers not creating Cgroups must create a private PID namespace - cannot use another: %w", define.ErrInvalidArg)
				}
				break
			}
		}
		if !foundPid {
			return fmt.Errorf("containers not creating Cgroups must create a private PID namespace: %w", define.ErrInvalidArg)
		}
	}

	// Can only set static IP or MAC is creating a network namespace.
	if !c.config.CreateNetNS && (c.config.StaticIP != nil || c.config.StaticMAC != nil) {
		return fmt.Errorf("cannot set static IP or MAC address if not creating a network namespace: %w", define.ErrInvalidArg)
	}

	// Cannot set static IP or MAC if joining >1 CNI network.
	if len(c.config.Networks) > 1 && (c.config.StaticIP != nil || c.config.StaticMAC != nil) {
		return fmt.Errorf("cannot set static IP or MAC address if joining more than one network: %w", define.ErrInvalidArg)
	}

	// Using image resolv.conf conflicts with various DNS settings.
	if c.config.UseImageResolvConf &&
		(len(c.config.DNSSearch) > 0 || len(c.config.DNSServer) > 0 ||
			len(c.config.DNSOption) > 0) {
		return fmt.Errorf("cannot configure DNS options if using image's resolv.conf: %w", define.ErrInvalidArg)
	}

	if c.config.UseImageHosts && len(c.config.HostAdd) > 0 {
		return fmt.Errorf("cannot add to /etc/hosts if using image's /etc/hosts: %w", define.ErrInvalidArg)
	}

	// Check named volume, overlay volume and image volume destination conflist
	destinations := make(map[string]bool)
	for _, vol := range c.config.NamedVolumes {
		// Don't check if they already exist.
		// If they don't we will automatically create them.
		if _, ok := destinations[vol.Dest]; ok {
			return fmt.Errorf("two volumes found with destination %s: %w", vol.Dest, define.ErrInvalidArg)
		}
		destinations[vol.Dest] = true
	}
	for _, vol := range c.config.OverlayVolumes {
		// Don't check if they already exist.
		// If they don't we will automatically create them.
		if _, ok := destinations[vol.Dest]; ok {
			return fmt.Errorf("two volumes found with destination %s: %w", vol.Dest, define.ErrInvalidArg)
		}
		destinations[vol.Dest] = true
	}
	for _, vol := range c.config.ImageVolumes {
		// Don't check if they already exist.
		// If they don't we will automatically create them.
		if _, ok := destinations[vol.Dest]; ok {
			return fmt.Errorf("two volumes found with destination %s: %w", vol.Dest, define.ErrInvalidArg)
		}
		destinations[vol.Dest] = true
	}

	// If User in the OCI spec is set, require that c.config.User is set for
	// security reasons (a lot of our code relies on c.config.User).
	if c.config.User == "" && (c.config.Spec.Process.User.UID != 0 || c.config.Spec.Process.User.GID != 0) {
		return fmt.Errorf("please set User explicitly via WithUser() instead of in OCI spec directly: %w", define.ErrInvalidArg)
	}

	// Init-ctrs must be used inside a Pod.  Check if a init container type is
	// passed and if no pod is passed
	if len(c.config.InitContainerType) > 0 && len(c.config.Pod) < 1 {
		return fmt.Errorf("init containers must be created in a pod: %w", define.ErrInvalidArg)
	}
	return nil
}