package cfclient

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"

	"github.com/pkg/errors"
)

type ServiceInstancesResponse struct {
	Count     int                       `json:"total_results"`
	Pages     int                       `json:"total_pages"`
	NextUrl   string                    `json:"next_url"`
	Resources []ServiceInstanceResource `json:"resources"`
}

type ServiceInstanceRequest struct {
	Name            string                 `json:"name"`
	SpaceGuid       string                 `json:"space_guid"`
	ServicePlanGuid string                 `json:"service_plan_guid"`
	Parameters      map[string]interface{} `json:"parameters,omitempty"`
	Tags            []string               `json:"tags,omitempty"`
}

type ServiceInstanceResource struct {
	Meta   Meta            `json:"metadata"`
	Entity ServiceInstance `json:"entity"`
}

type ServiceInstance struct {
	Name               string                 `json:"name"`
	CreatedAt          string                 `json:"created_at"`
	UpdatedAt          string                 `json:"updated_at"`
	Credentials        map[string]interface{} `json:"credentials"`
	ServicePlanGuid    string                 `json:"service_plan_guid"`
	SpaceGuid          string                 `json:"space_guid"`
	DashboardUrl       string                 `json:"dashboard_url"`
	Type               string                 `json:"type"`
	LastOperation      LastOperation          `json:"last_operation"`
	Tags               []string               `json:"tags"`
	ServiceGuid        string                 `json:"service_guid"`
	SpaceUrl           string                 `json:"space_url"`
	ServicePlanUrl     string                 `json:"service_plan_url"`
	ServiceBindingsUrl string                 `json:"service_bindings_url"`
	ServiceKeysUrl     string                 `json:"service_keys_url"`
	RoutesUrl          string                 `json:"routes_url"`
	ServiceUrl         string                 `json:"service_url"`
	Guid               string                 `json:"guid"`
	c                  *Client
}

type LastOperation struct {
	Type        string `json:"type"`
	State       string `json:"state"`
	Description string `json:"description"`
	UpdatedAt   string `json:"updated_at"`
	CreatedAt   string `json:"created_at"`
}

func (c *Client) ListServiceInstancesByQuery(query url.Values) ([]ServiceInstance, error) {
	var instances []ServiceInstance

	requestUrl := "/v2/service_instances?" + query.Encode()
	for {
		var sir ServiceInstancesResponse
		r := c.NewRequest("GET", requestUrl)
		resp, err := c.DoRequest(r)
		if err != nil {
			return nil, errors.Wrap(err, "Error requesting service instances")
		}
		resBody, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return nil, errors.Wrap(err, "Error reading service instances request:")
		}

		err = json.Unmarshal(resBody, &sir)
		if err != nil {
			return nil, errors.Wrap(err, "Error unmarshaling service instances")
		}
		for _, instance := range sir.Resources {
			instances = append(instances, c.mergeServiceInstance(instance))
		}

		requestUrl = sir.NextUrl
		if requestUrl == "" {
			break
		}
	}
	return instances, nil
}

func (c *Client) ListServiceInstances() ([]ServiceInstance, error) {
	return c.ListServiceInstancesByQuery(nil)
}

func (c *Client) GetServiceInstanceByGuid(guid string) (ServiceInstance, error) {
	var sir ServiceInstanceResource
	req := c.NewRequest("GET", "/v2/service_instances/"+guid)
	res, err := c.DoRequest(req)
	if err != nil {
		return ServiceInstance{}, errors.Wrap(err, "Error requesting service instance")
	}

	data, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return ServiceInstance{}, errors.Wrap(err, "Error reading service instance response")
	}
	err = json.Unmarshal(data, &sir)
	if err != nil {
		return ServiceInstance{}, errors.Wrap(err, "Error JSON parsing service instance response")
	}
	return c.mergeServiceInstance(sir), nil
}

func (c *Client) ServiceInstanceByGuid(guid string) (ServiceInstance, error) {
	return c.GetServiceInstanceByGuid(guid)
}

func (c *Client) mergeServiceInstance(instance ServiceInstanceResource) ServiceInstance {
	instance.Entity.Guid = instance.Meta.Guid
	instance.Entity.CreatedAt = instance.Meta.CreatedAt
	instance.Entity.UpdatedAt = instance.Meta.UpdatedAt
	instance.Entity.c = c
	return instance.Entity
}

func (c *Client) CreateServiceInstance(req ServiceInstanceRequest) (ServiceInstance, error) {
	var sir ServiceInstanceResource

	buf := bytes.NewBuffer(nil)
	err := json.NewEncoder(buf).Encode(req)
	if err != nil {
		return ServiceInstance{}, err
	}

	r := c.NewRequestWithBody("POST", "/v2/service_instances?accepts_incomplete=true", buf)

	res, err := c.DoRequest(r)
	if err != nil {
		return ServiceInstance{}, err
	}

	if res.StatusCode != http.StatusAccepted && res.StatusCode != http.StatusCreated {
		return ServiceInstance{}, errors.Wrapf(err, "Error creating service, response code: %d", res.StatusCode)
	}

	data, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return ServiceInstance{}, errors.Wrap(err, "Error reading service instance response")
	}

	err = json.Unmarshal(data, &sir)
	if err != nil {
		return ServiceInstance{}, errors.Wrap(err, "Error JSON parsing service instance response")
	}

	return c.mergeServiceInstance(sir), nil
}

func (c *Client) UpdateServiceInstance(serviceInstanceGuid string, updatedConfiguration io.Reader, async bool) error {
	u := fmt.Sprintf("/v2/service_instances/%s?accepts_incomplete=%t", serviceInstanceGuid, async)
	resp, err := c.DoRequest(c.NewRequestWithBody("PUT", u, updatedConfiguration))
	if err != nil {
		return err
	}
	if resp.StatusCode != http.StatusAccepted {
		return errors.Wrapf(err, "Error updating service instance %s, response code %d", serviceInstanceGuid, resp.StatusCode)
	}
	return nil
}

func (c *Client) DeleteServiceInstance(guid string, recursive, async bool) error {
	resp, err := c.DoRequest(c.NewRequest("DELETE", fmt.Sprintf("/v2/service_instances/%s?recursive=%t&accepts_incomplete=%t&async=%t", guid, recursive, async, async)))
	if err != nil {
		return err
	}
	if resp.StatusCode != http.StatusAccepted {
		return errors.Wrapf(err, "Error deleting service instance %s, response code %d", guid, resp.StatusCode)
	}
	return nil
}