//go:build !plan9 && !solaris && !js
// +build !plan9,!solaris,!js

package oracleobjectstorage

import (
	"time"

	"github.com/rclone/rclone/fs"
	"github.com/rclone/rclone/fs/config"
	"github.com/rclone/rclone/lib/encoder"
)

const (
	maxSizeForCopy             = 4768 * 1024 * 1024
	minChunkSize               = fs.SizeSuffix(1024 * 1024 * 5)
	defaultUploadCutoff        = fs.SizeSuffix(200 * 1024 * 1024)
	defaultUploadConcurrency   = 10
	maxUploadCutoff            = fs.SizeSuffix(5 * 1024 * 1024 * 1024)
	minSleep                   = 100 * time.Millisecond
	maxSleep                   = 5 * time.Minute
	decayConstant              = 1 // bigger for slower decay, exponential
	defaultCopyTimeoutDuration = fs.Duration(time.Minute)
)

const (
	userPrincipal     = "user_principal_auth"
	instancePrincipal = "instance_principal_auth"
	resourcePrincipal = "resource_principal_auth"
	environmentAuth   = "env_auth"
	noAuth            = "no_auth"

	userPrincipalHelpText = `use an OCI user and an API key for authentication.
you’ll need to put in a config file your tenancy OCID, user OCID, region, the path, fingerprint to an API key.
https://docs.oracle.com/en-us/iaas/Content/API/Concepts/sdkconfig.htm`

	instancePrincipalHelpText = `use instance principals to authorize an instance to make API calls. 
each instance has its own identity, and authenticates using the certificates that are read from instance metadata. 
https://docs.oracle.com/en-us/iaas/Content/Identity/Tasks/callingservicesfrominstances.htm`

	resourcePrincipalHelpText = `use resource principals to make API calls`

	environmentAuthHelpText = `automatically pickup the credentials from runtime(env), first one to provide auth wins`

	noAuthHelpText = `no credentials needed, this is typically for reading public buckets`
)

// Options defines the configuration for this backend
type Options struct {
	Provider          string               `config:"provider"`
	Compartment       string               `config:"compartment"`
	Namespace         string               `config:"namespace"`
	Region            string               `config:"region"`
	Endpoint          string               `config:"endpoint"`
	Enc               encoder.MultiEncoder `config:"encoding"`
	ConfigFile        string               `config:"config_file"`
	ConfigProfile     string               `config:"config_profile"`
	UploadCutoff      fs.SizeSuffix        `config:"upload_cutoff"`
	ChunkSize         fs.SizeSuffix        `config:"chunk_size"`
	UploadConcurrency int                  `config:"upload_concurrency"`
	DisableChecksum   bool                 `config:"disable_checksum"`
	CopyCutoff        fs.SizeSuffix        `config:"copy_cutoff"`
	CopyTimeout       fs.Duration          `config:"copy_timeout"`
	StorageTier       string               `config:"storage_tier"`
	LeavePartsOnError bool                 `config:"leave_parts_on_error"`
}

func newOptions() []fs.Option {
	return []fs.Option{{
		Name:     fs.ConfigProvider,
		Help:     "Choose your Auth Provider",
		Required: true,
		Default:  environmentAuth,
		Examples: []fs.OptionExample{{
			Value: environmentAuth,
			Help:  environmentAuthHelpText,
		}, {
			Value: userPrincipal,
			Help:  userPrincipalHelpText,
		}, {
			Value: instancePrincipal,
			Help:  instancePrincipalHelpText,
		}, {
			Value: resourcePrincipal,
			Help:  resourcePrincipalHelpText,
		}, {
			Value: noAuth,
			Help:  noAuthHelpText,
		}},
	}, {
		Name:     "namespace",
		Help:     "Object storage namespace",
		Required: true,
	}, {
		Name:     "compartment",
		Help:     "Object storage compartment OCID",
		Provider: "!no_auth",
		Required: true,
	}, {
		Name:     "region",
		Help:     "Object storage Region",
		Required: true,
	}, {
		Name:     "endpoint",
		Help:     "Endpoint for Object storage API.\n\nLeave blank to use the default endpoint for the region.",
		Required: false,
	}, {
		Name:     "config_file",
		Help:     "Path to OCI config file",
		Provider: userPrincipal,
		Default:  "~/.oci/config",
		Examples: []fs.OptionExample{{
			Value: "~/.oci/config",
			Help:  "oci configuration file location",
		}},
	}, {
		Name:     "config_profile",
		Help:     "Profile name inside the oci config file",
		Provider: userPrincipal,
		Default:  "Default",
		Examples: []fs.OptionExample{{
			Value: "Default",
			Help:  "Use the default profile",
		}},
	}, {
		Name: "upload_cutoff",
		Help: `Cutoff for switching to chunked upload.

Any files larger than this will be uploaded in chunks of chunk_size.
The minimum is 0 and the maximum is 5 GiB.`,
		Default:  defaultUploadCutoff,
		Advanced: true,
	}, {
		Name: "chunk_size",
		Help: `Chunk size to use for uploading.

When uploading files larger than upload_cutoff or files with unknown
size (e.g. from "rclone rcat" or uploaded with "rclone mount" or google
photos or google docs) they will be uploaded as multipart uploads
using this chunk size.

Note that "upload_concurrency" chunks of this size are buffered
in memory per transfer.

If you are transferring large files over high-speed links and you have
enough memory, then increasing this will speed up the transfers.

Rclone will automatically increase the chunk size when uploading a
large file of known size to stay below the 10,000 chunks limit.

Files of unknown size are uploaded with the configured
chunk_size. Since the default chunk size is 5 MiB and there can be at
most 10,000 chunks, this means that by default the maximum size of
a file you can stream upload is 48 GiB.  If you wish to stream upload
larger files then you will need to increase chunk_size.

Increasing the chunk size decreases the accuracy of the progress
statistics displayed with "-P" flag.
`,
		Default:  minChunkSize,
		Advanced: true,
	}, {
		Name: "upload_concurrency",
		Help: `Concurrency for multipart uploads.

This is the number of chunks of the same file that are uploaded
concurrently.

If you are uploading small numbers of large files over high-speed links
and these uploads do not fully utilize your bandwidth, then increasing
this may help to speed up the transfers.`,
		Default:  defaultUploadConcurrency,
		Advanced: true,
	}, {
		Name: "copy_cutoff",
		Help: `Cutoff for switching to multipart copy.

Any files larger than this that need to be server-side copied will be
copied in chunks of this size.

The minimum is 0 and the maximum is 5 GiB.`,
		Default:  fs.SizeSuffix(maxSizeForCopy),
		Advanced: true,
	}, {
		Name: "copy_timeout",
		Help: `Timeout for copy.

Copy is an asynchronous operation, specify timeout to wait for copy to succeed
`,
		Default:  defaultCopyTimeoutDuration,
		Advanced: true,
	}, {
		Name: "disable_checksum",
		Help: `Don't store MD5 checksum with object metadata.

Normally rclone will calculate the MD5 checksum of the input before
uploading it so it can add it to metadata on the object. This is great
for data integrity checking but can cause long delays for large files
to start uploading.`,
		Default:  false,
		Advanced: true,
	}, {
		Name:     config.ConfigEncoding,
		Help:     config.ConfigEncodingHelp,
		Advanced: true,
		// Any UTF-8 character is valid in a key, however it can't handle
		// invalid UTF-8 and / have a special meaning.
		//
		// The SDK can't seem to handle uploading files called '.
		// - initial / encoding
		// - doubled / encoding
		// - trailing / encoding
		// so that OSS keys are always valid file names
		Default: encoder.EncodeInvalidUtf8 |
			encoder.EncodeSlash |
			encoder.EncodeDot,
	}, {
		Name: "leave_parts_on_error",
		Help: `If true avoid calling abort upload on a failure, leaving all successfully uploaded parts on S3 for manual recovery.

It should be set to true for resuming uploads across different sessions.

WARNING: Storing parts of an incomplete multipart upload counts towards space usage on object storage and will add
additional costs if not cleaned up.
`,
		Default:  false,
		Advanced: true,
	}}
}