/*
Copyright © The ESO Authors

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 bitwarden implements a secret manager provider for Bitwarden.
package bitwarden

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"

	"sigs.k8s.io/controller-runtime/pkg/client"

	esv1 "github.com/external-secrets/external-secrets/apis/externalsecrets/v1"
)

// Defined Header Keys.
const (
	WardenHeaderAccessToken = "Warden-Access-Token"
	WardenHeaderAPIURL      = "Warden-Api-Url"
	WardenHeaderIdentityURL = "Warden-Identity-Url"

	restAPIURL = "/rest/api/1/secret"
)

// SecretResponse represents a response from the Bitwarden API containing secret details.
type SecretResponse struct {
	CreationDate   string  `json:"creationDate"`
	ID             string  `json:"id"`
	Key            string  `json:"key"`
	Note           string  `json:"note"`
	OrganizationID string  `json:"organizationId"`
	ProjectID      *string `json:"projectId,omitempty"`
	RevisionDate   string  `json:"revisionDate"`
	Value          string  `json:"value"`
	// fix ProjectIDS -> ProjectIDs
	ProjectIDs []string `json:"projectIds,omitempty"`
}

// SecretsDeleteResponse represents the response when deleting multiple secrets.
type SecretsDeleteResponse struct {
	Data []SecretDeleteResponse `json:"data"`
}

// SecretDeleteResponse represents the response for a single secret deletion.
type SecretDeleteResponse struct {
	Error *string `json:"error,omitempty"`
	ID    string  `json:"id"`
}

// SecretIdentifiersResponse represents the response when listing secret identifiers.
type SecretIdentifiersResponse struct {
	Data []SecretIdentifierResponse `json:"data"`
}

// SecretIdentifierResponse represents a single secret identifier in a list response.
type SecretIdentifierResponse struct {
	ID             string `json:"id"`
	Key            string `json:"key"`
	OrganizationID string `json:"organizationId"`
}

// SecretCreateRequest represents the request to create a new secret.
type SecretCreateRequest struct {
	Key  string `json:"key"`
	Note string `json:"note"`
	// Organization where the secret will be created
	OrganizationID string `json:"organizationId"`
	// IDs of the projects that this secret will belong to
	ProjectIDs []string `json:"projectIds,omitempty"` // Changed from ProjectIDS
	Value      string   `json:"value"`
}

// SecretPutRequest represents the request to update an existing secret.
type SecretPutRequest struct {
	ID   string `json:"id"`
	Key  string `json:"key"`
	Note string `json:"note"`
	// Organization where the secret will be created
	OrganizationID string `json:"organizationId"`
	// IDs of the projects that this secret will belong to
	ProjectIDs []string `json:"projectIds,omitempty"` // Changed from ProjectIDS
	Value      string   `json:"value"`
}

// Client for the bitwarden SDK.
type Client interface {
	GetSecret(ctx context.Context, id string) (*SecretResponse, error)
	DeleteSecret(ctx context.Context, ids []string) (*SecretsDeleteResponse, error)
	CreateSecret(ctx context.Context, secret SecretCreateRequest) (*SecretResponse, error)
	UpdateSecret(ctx context.Context, secret SecretPutRequest) (*SecretResponse, error)
	ListSecrets(ctx context.Context, organizationID string) (*SecretIdentifiersResponse, error)
}

// SdkClient creates a client to talk to the bitwarden SDK server.
type SdkClient struct {
	apiURL                string
	identityURL           string
	token                 string
	bitwardenSdkServerURL string

	client *http.Client
}

// NewSdkClient creates a new Bitwarden SDK client instance.
func NewSdkClient(ctx context.Context, c client.Client, storeKind, namespace string, provider *esv1.BitwardenSecretsManagerProvider, token string) (*SdkClient, error) {
	httpsClient, err := newHTTPSClient(ctx, c, storeKind, namespace, provider)
	if err != nil {
		return nil, fmt.Errorf("error creating https client: %w", err)
	}

	return &SdkClient{
		apiURL:                strings.TrimSuffix(provider.APIURL, "/"),
		identityURL:           strings.TrimSuffix(provider.IdentityURL, "/"),
		bitwardenSdkServerURL: provider.BitwardenServerSDKURL,
		token:                 token,
		client:                httpsClient,
	}, nil
}

// GetSecret retrieves a secret from Bitwarden by its ID.
func (s *SdkClient) GetSecret(ctx context.Context, id string) (*SecretResponse, error) {
	body := struct {
		ID string `json:"id"`
	}{
		ID: id,
	}
	secretResp := &SecretResponse{}

	if err := s.performHTTPRequestOperation(ctx, params{
		method: http.MethodGet,
		url:    s.bitwardenSdkServerURL + restAPIURL,
		body:   body,
		result: &secretResp,
	}); err != nil {
		return nil, fmt.Errorf("failed to get secret: %w", err)
	}

	return secretResp, nil
}

// DeleteSecret deletes secrets from Bitwarden by their IDs.
func (s *SdkClient) DeleteSecret(ctx context.Context, ids []string) (*SecretsDeleteResponse, error) {
	body := struct {
		IDs []string `json:"ids"`
	}{
		IDs: ids,
	}

	secretResp := &SecretsDeleteResponse{}
	if err := s.performHTTPRequestOperation(ctx, params{
		method: http.MethodDelete,
		url:    s.bitwardenSdkServerURL + restAPIURL,
		body:   body,
		result: &secretResp,
	}); err != nil {
		return nil, fmt.Errorf("failed to delete secret: %w", err)
	}

	return secretResp, nil
}

// CreateSecret creates a new secret in Bitwarden.
func (s *SdkClient) CreateSecret(ctx context.Context, createReq SecretCreateRequest) (*SecretResponse, error) {
	secretResp := &SecretResponse{}
	if err := s.performHTTPRequestOperation(ctx, params{
		method: http.MethodPost,
		url:    s.bitwardenSdkServerURL + restAPIURL,
		body:   createReq,
		result: &secretResp,
	}); err != nil {
		return nil, fmt.Errorf("failed to create secret: %w", err)
	}

	return secretResp, nil
}

// UpdateSecret updates an existing secret in Bitwarden.
func (s *SdkClient) UpdateSecret(ctx context.Context, putReq SecretPutRequest) (*SecretResponse, error) {
	secretResp := &SecretResponse{}
	if err := s.performHTTPRequestOperation(ctx, params{
		method: http.MethodPut,
		url:    s.bitwardenSdkServerURL + restAPIURL,
		body:   putReq,
		result: &secretResp,
	}); err != nil {
		return nil, fmt.Errorf("failed to update secret: %w", err)
	}

	return secretResp, nil
}

// ListSecrets retrieves all secrets from a Bitwarden organization.
func (s *SdkClient) ListSecrets(ctx context.Context, organizationID string) (*SecretIdentifiersResponse, error) {
	body := struct {
		ID string `json:"organizationID"`
	}{
		ID: organizationID,
	}
	secretResp := &SecretIdentifiersResponse{}
	if err := s.performHTTPRequestOperation(ctx, params{
		method: http.MethodGet,
		url:    s.bitwardenSdkServerURL + "/rest/api/1/secrets",
		body:   body,
		result: &secretResp,
	}); err != nil {
		return nil, fmt.Errorf("failed to list secrets: %w", err)
	}

	return secretResp, nil
}

func (s *SdkClient) constructSdkRequest(ctx context.Context, method, url string, body []byte) (*http.Request, error) {
	req, err := http.NewRequestWithContext(ctx, method, url, bytes.NewBuffer(body))
	if err != nil {
		return nil, fmt.Errorf("failed to construct request: %w", err)
	}

	req.Header.Set(WardenHeaderAccessToken, s.token)
	req.Header.Set(WardenHeaderAPIURL, s.apiURL)
	req.Header.Set(WardenHeaderIdentityURL, s.identityURL)

	return req, nil
}

type params struct {
	method string
	url    string
	body   any
	result any
}

func (s *SdkClient) performHTTPRequestOperation(ctx context.Context, params params) error {
	data, err := json.Marshal(params.body)
	if err != nil {
		return fmt.Errorf("failed to marshal body: %w", err)
	}

	req, err := s.constructSdkRequest(ctx, params.method, params.url, data)
	if err != nil {
		return fmt.Errorf("failed to construct request: %w", err)
	}

	resp, err := s.client.Do(req)
	if err != nil {
		return fmt.Errorf("failed to do request: %w", err)
	}
	defer func() {
		_ = resp.Body.Close()
	}()

	if resp.StatusCode != http.StatusOK {
		content, _ := io.ReadAll(resp.Body)

		return fmt.Errorf("failed to perform http request, got response: %s with status code %d", string(content), resp.StatusCode)
	}

	decoder := json.NewDecoder(resp.Body)
	if err := decoder.Decode(&params.result); err != nil {
		return fmt.Errorf("failed to decode response: %w", err)
	}

	return nil
}
