// Copyright 2016, Google
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package b2

import (
	"context"
	"io"
	"net/http"
	"time"

	"github.com/kurin/blazer/base"
)

// This file wraps the base package in a thin layer, for testing.  It should be
// the only file in b2 that imports base.

type b2RootInterface interface {
	authorizeAccount(context.Context, string, string, ...ClientOption) error
	transient(error) bool
	backoff(error) time.Duration
	reauth(error) bool
	reupload(error) bool
	createBucket(context.Context, string, string, map[string]string, []LifecycleRule) (b2BucketInterface, error)
	listBuckets(context.Context) ([]b2BucketInterface, error)
}

type b2BucketInterface interface {
	name() string
	btype() string
	attrs() *BucketAttrs
	updateBucket(context.Context, *BucketAttrs) error
	deleteBucket(context.Context) error
	getUploadURL(context.Context) (b2URLInterface, error)
	startLargeFile(ctx context.Context, name, contentType string, info map[string]string) (b2LargeFileInterface, error)
	listFileNames(context.Context, int, string, string, string) ([]b2FileInterface, string, error)
	listFileVersions(context.Context, int, string, string, string, string) ([]b2FileInterface, string, string, error)
	listUnfinishedLargeFiles(context.Context, int, string) ([]b2FileInterface, string, error)
	downloadFileByName(context.Context, string, int64, int64) (b2FileReaderInterface, error)
	hideFile(context.Context, string) (b2FileInterface, error)
	getDownloadAuthorization(context.Context, string, time.Duration) (string, error)
	baseURL() string
	file(string, string) b2FileInterface
}

type b2URLInterface interface {
	reload(context.Context) error
	uploadFile(context.Context, io.Reader, int, string, string, string, map[string]string) (b2FileInterface, error)
}

type b2FileInterface interface {
	name() string
	size() int64
	timestamp() time.Time
	status() string
	deleteFileVersion(context.Context) error
	getFileInfo(context.Context) (b2FileInfoInterface, error)
	listParts(context.Context, int, int) ([]b2FilePartInterface, int, error)
	compileParts(int64, map[int]string) b2LargeFileInterface
}

type b2LargeFileInterface interface {
	finishLargeFile(context.Context) (b2FileInterface, error)
	getUploadPartURL(context.Context) (b2FileChunkInterface, error)
}

type b2FileChunkInterface interface {
	reload(context.Context) error
	uploadPart(context.Context, io.Reader, string, int, int) (int, error)
}

type b2FileReaderInterface interface {
	io.ReadCloser
	stats() (int, string, string, map[string]string)
	id() string
}

type b2FileInfoInterface interface {
	stats() (string, string, int64, string, map[string]string, string, time.Time) // bleck
}

type b2FilePartInterface interface {
	number() int
	sha1() string
	size() int64
}

type b2Root struct {
	b *base.B2
}

type b2Bucket struct {
	b *base.Bucket
}

type b2URL struct {
	b *base.URL
}

type b2File struct {
	b *base.File
}

type b2LargeFile struct {
	b *base.LargeFile
}

type b2FileChunk struct {
	b *base.FileChunk
}

type b2FileReader struct {
	b *base.FileReader
}

type b2FileInfo struct {
	b *base.FileInfo
}

type b2FilePart struct {
	b *base.FilePart
}

func (b *b2Root) authorizeAccount(ctx context.Context, account, key string, opts ...ClientOption) error {
	c := &clientOptions{}
	for _, f := range opts {
		f(c)
	}
	var aopts []base.AuthOption
	ct := &clientTransport{client: c.client}
	if c.transport != nil {
		ct.rt = c.transport
	}
	aopts = append(aopts, base.Transport(ct))
	if c.failSomeUploads {
		aopts = append(aopts, base.FailSomeUploads())
	}
	if c.expireTokens {
		aopts = append(aopts, base.ExpireSomeAuthTokens())
	}
	if c.capExceeded {
		aopts = append(aopts, base.ForceCapExceeded())
	}
	for _, agent := range c.userAgents {
		aopts = append(aopts, base.UserAgent(agent))
	}
	nb, err := base.AuthorizeAccount(ctx, account, key, aopts...)
	if err != nil {
		return err
	}
	if b.b == nil {
		b.b = nb
		return nil
	}
	b.b.Update(nb)
	return nil
}

func (*b2Root) backoff(err error) time.Duration {
	if base.Action(err) != base.Retry {
		return 0
	}
	return base.Backoff(err)
}

func (*b2Root) reauth(err error) bool {
	return base.Action(err) == base.ReAuthenticate
}

func (*b2Root) reupload(err error) bool {
	return base.Action(err) == base.AttemptNewUpload
}

func (*b2Root) transient(err error) bool {
	return base.Action(err) == base.Retry
}

func (b *b2Root) createBucket(ctx context.Context, name, btype string, info map[string]string, rules []LifecycleRule) (b2BucketInterface, error) {
	var baseRules []base.LifecycleRule
	for _, rule := range rules {
		baseRules = append(baseRules, base.LifecycleRule{
			DaysNewUntilHidden:     rule.DaysNewUntilHidden,
			DaysHiddenUntilDeleted: rule.DaysHiddenUntilDeleted,
			Prefix:                 rule.Prefix,
		})
	}
	bucket, err := b.b.CreateBucket(ctx, name, btype, info, baseRules)
	if err != nil {
		return nil, err
	}
	return &b2Bucket{bucket}, nil
}

func (b *b2Root) listBuckets(ctx context.Context) ([]b2BucketInterface, error) {
	buckets, err := b.b.ListBuckets(ctx)
	if err != nil {
		return nil, err
	}
	var rtn []b2BucketInterface
	for _, bucket := range buckets {
		rtn = append(rtn, &b2Bucket{bucket})
	}
	return rtn, err
}

func (b *b2Bucket) updateBucket(ctx context.Context, attrs *BucketAttrs) error {
	if attrs == nil {
		return nil
	}
	if attrs.Type != UnknownType {
		b.b.Type = string(attrs.Type)
	}
	if attrs.Info != nil {
		b.b.Info = attrs.Info
	}
	if attrs.LifecycleRules != nil {
		rules := []base.LifecycleRule{}
		for _, rule := range attrs.LifecycleRules {
			rules = append(rules, base.LifecycleRule{
				DaysNewUntilHidden:     rule.DaysNewUntilHidden,
				DaysHiddenUntilDeleted: rule.DaysHiddenUntilDeleted,
				Prefix:                 rule.Prefix,
			})
		}
		b.b.LifecycleRules = rules
	}
	newBucket, err := b.b.Update(ctx)
	if err == nil {
		b.b = newBucket
	}
	code, _ := base.Code(err)
	if code == 409 {
		return b2err{
			err:              err,
			isUpdateConflict: true,
		}
	}
	return err
}

func (b *b2Bucket) deleteBucket(ctx context.Context) error {
	return b.b.DeleteBucket(ctx)
}

func (b *b2Bucket) name() string {
	return b.b.Name
}

func (b *b2Bucket) btype() string {
	return b.b.Type
}

func (b *b2Bucket) attrs() *BucketAttrs {
	var rules []LifecycleRule
	for _, rule := range b.b.LifecycleRules {
		rules = append(rules, LifecycleRule{
			DaysNewUntilHidden:     rule.DaysNewUntilHidden,
			DaysHiddenUntilDeleted: rule.DaysHiddenUntilDeleted,
			Prefix:                 rule.Prefix,
		})
	}
	return &BucketAttrs{
		LifecycleRules: rules,
		Info:           b.b.Info,
		Type:           BucketType(b.b.Type),
	}
}

func (b *b2Bucket) getUploadURL(ctx context.Context) (b2URLInterface, error) {
	url, err := b.b.GetUploadURL(ctx)
	if err != nil {
		return nil, err
	}
	return &b2URL{url}, nil
}

func (b *b2Bucket) startLargeFile(ctx context.Context, name, ct string, info map[string]string) (b2LargeFileInterface, error) {
	lf, err := b.b.StartLargeFile(ctx, name, ct, info)
	if err != nil {
		return nil, err
	}
	return &b2LargeFile{lf}, nil
}

func (b *b2Bucket) listFileNames(ctx context.Context, count int, continuation, prefix, delimiter string) ([]b2FileInterface, string, error) {
	fs, c, err := b.b.ListFileNames(ctx, count, continuation, prefix, delimiter)
	if err != nil {
		return nil, "", err
	}
	var files []b2FileInterface
	for _, f := range fs {
		files = append(files, &b2File{f})
	}
	return files, c, nil
}

func (b *b2Bucket) listFileVersions(ctx context.Context, count int, nextName, nextID, prefix, delimiter string) ([]b2FileInterface, string, string, error) {
	fs, name, id, err := b.b.ListFileVersions(ctx, count, nextName, nextID, prefix, delimiter)
	if err != nil {
		return nil, "", "", err
	}
	var files []b2FileInterface
	for _, f := range fs {
		files = append(files, &b2File{f})
	}
	return files, name, id, nil
}

func (b *b2Bucket) listUnfinishedLargeFiles(ctx context.Context, count int, continuation string) ([]b2FileInterface, string, error) {
	fs, cont, err := b.b.ListUnfinishedLargeFiles(ctx, count, continuation)
	if err != nil {
		return nil, "", err
	}
	var files []b2FileInterface
	for _, f := range fs {
		files = append(files, &b2File{f})
	}
	return files, cont, nil
}

func (b *b2Bucket) downloadFileByName(ctx context.Context, name string, offset, size int64) (b2FileReaderInterface, error) {
	fr, err := b.b.DownloadFileByName(ctx, name, offset, size)
	if err != nil {
		code, _ := base.Code(err)
		switch code {
		case http.StatusRequestedRangeNotSatisfiable:
			return nil, errNoMoreContent
		case http.StatusNotFound:
			return nil, b2err{err: err, notFoundErr: true}
		}
		return nil, err
	}
	return &b2FileReader{fr}, nil
}

func (b *b2Bucket) hideFile(ctx context.Context, name string) (b2FileInterface, error) {
	f, err := b.b.HideFile(ctx, name)
	if err != nil {
		return nil, err
	}
	return &b2File{f}, nil
}

func (b *b2Bucket) getDownloadAuthorization(ctx context.Context, p string, v time.Duration) (string, error) {
	return b.b.GetDownloadAuthorization(ctx, p, v)
}

func (b *b2Bucket) baseURL() string {
	return b.b.BaseURL()
}

func (b *b2Bucket) file(id, name string) b2FileInterface { return &b2File{b.b.File(id, name)} }

func (b *b2URL) uploadFile(ctx context.Context, r io.Reader, size int, name, contentType, sha1 string, info map[string]string) (b2FileInterface, error) {
	file, err := b.b.UploadFile(ctx, r, size, name, contentType, sha1, info)
	if err != nil {
		return nil, err
	}
	return &b2File{file}, nil
}

func (b *b2URL) reload(ctx context.Context) error {
	return b.b.Reload(ctx)
}

func (b *b2File) deleteFileVersion(ctx context.Context) error {
	return b.b.DeleteFileVersion(ctx)
}

func (b *b2File) name() string {
	return b.b.Name
}

func (b *b2File) size() int64 {
	return b.b.Size
}

func (b *b2File) timestamp() time.Time {
	return b.b.Timestamp
}

func (b *b2File) status() string {
	return b.b.Status
}

func (b *b2File) getFileInfo(ctx context.Context) (b2FileInfoInterface, error) {
	if b.b.Info != nil {
		return &b2FileInfo{b.b.Info}, nil
	}
	fi, err := b.b.GetFileInfo(ctx)
	if err != nil {
		return nil, err
	}
	return &b2FileInfo{fi}, nil
}

func (b *b2File) listParts(ctx context.Context, next, count int) ([]b2FilePartInterface, int, error) {
	parts, n, err := b.b.ListParts(ctx, next, count)
	if err != nil {
		return nil, 0, err
	}
	var rtn []b2FilePartInterface
	for _, part := range parts {
		rtn = append(rtn, &b2FilePart{part})
	}
	return rtn, n, nil
}

func (b *b2File) compileParts(size int64, seen map[int]string) b2LargeFileInterface {
	return &b2LargeFile{b.b.CompileParts(size, seen)}
}

func (b *b2LargeFile) finishLargeFile(ctx context.Context) (b2FileInterface, error) {
	f, err := b.b.FinishLargeFile(ctx)
	if err != nil {
		return nil, err
	}
	return &b2File{f}, nil
}

func (b *b2LargeFile) getUploadPartURL(ctx context.Context) (b2FileChunkInterface, error) {
	c, err := b.b.GetUploadPartURL(ctx)
	if err != nil {
		return nil, err
	}
	return &b2FileChunk{c}, nil
}

func (b *b2FileChunk) reload(ctx context.Context) error {
	return b.b.Reload(ctx)
}

func (b *b2FileChunk) uploadPart(ctx context.Context, r io.Reader, sha1 string, size, index int) (int, error) {
	return b.b.UploadPart(ctx, r, sha1, size, index)
}

func (b *b2FileReader) Read(p []byte) (int, error) {
	return b.b.Read(p)
}

func (b *b2FileReader) Close() error {
	return b.b.Close()
}

func (b *b2FileReader) stats() (int, string, string, map[string]string) {
	return b.b.ContentLength, b.b.ContentType, b.b.SHA1, b.b.Info
}

func (b *b2FileReader) id() string { return b.b.ID }

func (b *b2FileInfo) stats() (string, string, int64, string, map[string]string, string, time.Time) {
	return b.b.Name, b.b.SHA1, b.b.Size, b.b.ContentType, b.b.Info, b.b.Status, b.b.Timestamp
}

func (b *b2FilePart) number() int  { return b.b.Number }
func (b *b2FilePart) sha1() string { return b.b.SHA1 }
func (b *b2FilePart) size() int64  { return b.b.Size }