package permissions

import (
	"context"
	"fmt"
	"net/http"

	"go.infratographer.com/x/gidx"
)

type resourceRelationship struct {
	ResourceID string `json:"resource_id"`
	Relation   string `json:"relation"`
	SubjectID  string `json:"subject_id"`
}

// ResourceRelationship defines the resource to subject relationship.
type ResourceRelationship struct {
	ResourceID gidx.PrefixedID
	Relation   string
	SubjectID  gidx.PrefixedID
}

// ResourceRelationshipRequest defines the request to relate to a subject.
type ResourceRelationshipRequest struct {
	Relation  string `json:"relation"`
	SubjectID string `json:"subject_id"`
}

// ResourceRelationshipDeleteResponse defines the response for a delete of a relationship.
type ResourceRelationshipDeleteResponse struct {
	Success bool `json:"success"`
}

// DeleteResourceRelationship deletes the provided resources relationship to the given subject id.
func (c *client) DeleteResourceRelationship(ctx context.Context, resourceID gidx.PrefixedID, relation string, relatedResourceID gidx.PrefixedID) error {
	path := fmt.Sprintf("/api/v1/resources/%s/relationships", resourceID.String())

	body, err := encodeJSON(ResourceRelationshipRequest{
		Relation:  relation,
		SubjectID: relatedResourceID.String(),
	})
	if err != nil {
		return err
	}

	var response ResourceRelationshipDeleteResponse

	if _, err := c.DoRequest(ctx, http.MethodDelete, path, body, &response); err != nil { // nolint:bodyclose // closed by Do on json decode.
		return err
	}

	if !response.Success {
		return ErrUnexpectedRelationshipDeleteFailed
	}

	return nil
}

// ListResourceRelationshipsFrom returns resources related to the given id.
func (c *client) ListResourceRelationshipsFrom(ctx context.Context, resourceID gidx.PrefixedID) ([]ResourceRelationship, error) {
	var response struct {
		Data []resourceRelationship `json:"data"`
	}

	if _, err := c.DoRequest(ctx, http.MethodGet, fmt.Sprintf("/api/v1/relationships/from/%s", resourceID.String()), nil, &response); err != nil { // nolint:bodyclose // closed by Do on json decode.
		return nil, err
	}

	data := make([]ResourceRelationship, len(response.Data))

	for i, entry := range response.Data {
		subID, err := gidx.Parse(entry.SubjectID)
		if err != nil {
			return nil, err
		}

		data[i] = ResourceRelationship{
			Relation:  entry.Relation,
			SubjectID: subID,
		}
	}

	return data, nil
}

// ListResourceRelationshipsTo returns resources related to the given id.
func (c *client) ListResourceRelationshipsTo(ctx context.Context, resourceID gidx.PrefixedID) ([]ResourceRelationship, error) {
	var response struct {
		Data []resourceRelationship `json:"data"`
	}

	if _, err := c.DoRequest(ctx, http.MethodGet, fmt.Sprintf("/api/v1/relationships/to/%s", resourceID.String()), nil, &response); err != nil { // nolint:bodyclose // closed by Do on json decode.
		return nil, err
	}

	data := make([]ResourceRelationship, len(response.Data))

	for i, entry := range response.Data {
		resID, err := gidx.Parse(entry.ResourceID)
		if err != nil {
			return nil, err
		}

		data[i] = ResourceRelationship{
			ResourceID: resID,
			Relation:   entry.Relation,
		}
	}

	return data, nil
}