/*
 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

     https://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 config

import (
	"fmt"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/transport"
	"github.com/go-git/go-git/v5/plumbing/transport/http"
	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
	"sigs.k8s.io/yaml"

	"opendev.org/airship/airshipctl/pkg/errors"
)

const (
	SSHAuth   = "ssh-key"
	SSHPass   = "ssh-pass"
	HTTPBasic = "http-basic"
)

// RepoCheckout methods

func (c *RepoCheckout) String() string {
	yaml, err := yaml.Marshal(&c)
	if err != nil {
		return ""
	}
	return string(yaml)
}

func (c *RepoCheckout) Validate() error {
	possibleValues := []string{c.CommitHash, c.Branch, c.Tag, c.RemoteRef}
	var count int
	for _, val := range possibleValues {
		if val != "" {
			count++
		}
	}
	if count > 1 {
		return ErrMutuallyExclusiveCheckout{}
	}
	if c.RemoteRef != "" {
		return fmt.Errorf("Repository checkout by RemoteRef is not yet implemented\n%w", errors.ErrNotImplemented{})
	}
	return nil
}

// RepoAuth methods
var (
	AllowedAuthTypes = []string{SSHAuth, SSHPass, HTTPBasic}
)

func (auth *RepoAuth) String() string {
	yaml, err := yaml.Marshal(&auth)
	if err != nil {
		return ""
	}
	return string(yaml)
}

func (auth *RepoAuth) Validate() error {
	if !stringInSlice(auth.Type, AllowedAuthTypes) {
		return ErrAuthTypeNotSupported{}
	}

	switch auth.Type {
	case SSHAuth:
		if auth.HTTPPassword != "" || auth.SSHPassword != "" {
			return NewErrIncompetibleAuthOptions([]string{"http-pass, ssh-pass"}, auth.Type)
		}
	case HTTPBasic:
		if auth.SSHPassword != "" || auth.KeyPath != "" || auth.KeyPassword != "" {
			return NewErrIncompetibleAuthOptions([]string{"ssh-pass, ssh-key, key-pass"}, auth.Type)
		}
	case SSHPass:
		if auth.KeyPath != "" || auth.KeyPassword != "" || auth.HTTPPassword != "" {
			return NewErrIncompetibleAuthOptions([]string{"ssh-key, key-pass, http-pass"}, auth.Type)
		}
	}
	return nil
}

func stringInSlice(a string, list []string) bool {
	for _, b := range list {
		if b == a {
			return true
		}
	}
	return false
}

// Repository functions

func (repo *Repository) String() string {
	yaml, err := yaml.Marshal(&repo)
	if err != nil {
		return ""
	}
	return string(yaml)
}

func (repo *Repository) Validate() error {
	if repo.URLString == "" {
		return ErrRepoSpecRequiresURL{}
	}

	if repo.Auth != nil {
		err := repo.Auth.Validate()
		if err != nil {
			return err
		}
	}

	if repo.CheckoutOptions != nil {
		err := repo.CheckoutOptions.Validate()
		if err != nil {
			return err
		}
	}

	return nil
}

func (repo *Repository) ToAuth() (transport.AuthMethod, error) {
	if repo.Auth == nil {
		return nil, nil
	}
	switch repo.Auth.Type {
	case SSHAuth:
		return ssh.NewPublicKeysFromFile(repo.Auth.Username, repo.Auth.KeyPath, repo.Auth.KeyPassword)
	case SSHPass:
		return &ssh.Password{User: repo.Auth.Username, Password: repo.Auth.HTTPPassword}, nil
	case HTTPBasic:
		return &http.BasicAuth{Username: repo.Auth.Username, Password: repo.Auth.HTTPPassword}, nil
	default:
		return nil, fmt.Errorf("Error building auth opts, repo\n%s\n: %w", repo.String(), errors.ErrNotImplemented{})
	}
}

func (repo *Repository) ToCheckoutOptions(force bool) *git.CheckoutOptions {
	co := &git.CheckoutOptions{
		Force: force,
	}
	switch {
	case repo.CheckoutOptions == nil:
	case repo.CheckoutOptions.Branch != "":
		co.Branch = plumbing.NewBranchReferenceName(repo.CheckoutOptions.Branch)
	case repo.CheckoutOptions.Tag != "":
		co.Branch = plumbing.NewTagReferenceName(repo.CheckoutOptions.Tag)
	case repo.CheckoutOptions.CommitHash != "":
		co.Hash = plumbing.NewHash(repo.CheckoutOptions.CommitHash)
	}
	return co
}

func (repo *Repository) ToCloneOptions(auth transport.AuthMethod) *git.CloneOptions {
	return &git.CloneOptions{
		Auth: auth,
		URL:  repo.URLString,
	}
}

func (repo *Repository) ToFetchOptions(auth transport.AuthMethod) *git.FetchOptions {
	return &git.FetchOptions{Auth: auth}
}

func (repo *Repository) URL() string {
	return repo.URLString
}