package fastly

import (
        "fmt"
        "sort"
)

// Backend represents a backend response from the Fastly API.
type Backend struct {
        ServiceID string `mapstructure:"service_id"`
        Version   string `mapstructure:"version"`

        Name                string   `mapstructure:"name"`
        Address             string   `mapstructure:"address"`
        Port                uint     `mapstructure:"port"`
        ConnectTimeout      uint     `mapstructure:"connect_timeout"`
        MaxConn             uint     `mapstructure:"max_conn"`
        ErrorThreshold      uint     `mapstructure:"error_threshold"`
        FirstByteTimeout    uint     `mapstructure:"first_byte_timeout"`
        BetweenBytesTimeout uint     `mapstructure:"between_bytes_timeout"`
        AutoLoadbalance     bool     `mapstructure:"auto_loadbalance"`
        Weight              uint     `mapstructure:"weight"`
        RequestCondition    string   `mapstructure:"request_condition"`
        HealthCheck         string   `mapstructure:"healthcheck"`
        UseSSL              bool     `mapstructure:"use_ssl"`
        SSLCheckCert        bool     `mapstructure:"ssl_check_cert"`
        SSLHostname         string   `mapstructure:"ssl_hostname"`
        SSLCertHostname     string   `mapstructure:"ssl_cert_hostname"`
        SSLSNIHostname      string   `mapstructure:"ssl_sni_hostname"`
        MinTLSVersion       string   `mapstructure:"min_tls_version"`
        MaxTLSVersion       string   `mapstructure:"max_tls_version"`
        SSLCiphers          []string `mapstructure:"ssl_ciphers"`
}

// backendsByName is a sortable list of backends.
type backendsByName []*Backend

// Len, Swap, and Less implement the sortable interface.
func (s backendsByName) Len() int      { return len(s) }
func (s backendsByName) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s backendsByName) Less(i, j int) bool {
        return s[i].Name < s[j].Name
}

// ListBackendsInput is used as input to the ListBackends function.
type ListBackendsInput struct {
        // Service is the ID of the service (required).
        Service string

        // Version is the specific configuration version (required).
        Version string
}

// ListBackends returns the list of backends for the configuration version.
func (c *Client) ListBackends(i *ListBackendsInput) ([]*Backend, error) {
        if i.Service == "" {
                return nil, ErrMissingService
        }

        if i.Version == "" {
                return nil, ErrMissingVersion
        }

        path := fmt.Sprintf("/service/%s/version/%s/backend", i.Service, i.Version)
        resp, err := c.Get(path, nil)
        if err != nil {
                return nil, err
        }

        var bs []*Backend
        if err := decodeJSON(&bs, resp.Body); err != nil {
                return nil, err
        }
        sort.Stable(backendsByName(bs))
        return bs, nil
}

// CreateBackendInput is used as input to the CreateBackend function.
type CreateBackendInput struct {
        // Service is the ID of the service. Version is the specific configuration
        // version. Both fields are required.
        Service string
        Version string

        Name                string   `form:"name,omitempty"`
        Address             string   `form:"address,omitempty"`
        Port                uint     `form:"port,omitempty"`
        ConnectTimeout      uint     `form:"connect_timeout,omitempty"`
        MaxConn             uint     `form:"max_conn,omitempty"`
        ErrorThreshold      uint     `form:"error_threshold,omitempty"`
        FirstByteTimeout    uint     `form:"first_byte_timeout,omitempty"`
        BetweenBytesTimeout uint     `form:"between_bytes_timeout,omitempty"`
        AutoLoadbalance     bool     `form:"auto_loadbalance,omitempty"`
        Weight              uint     `form:"weight,omitempty"`
        RequestCondition    string   `form:"request_condition,omitempty"`
        HealthCheck         string   `form:"healthcheck,omitempty"`
        UseSSL              bool     `form:"use_ssl,omitempty"`
        SSLCheckCert        bool     `form:"ssl_check_cert,omitempty"`
        SSLHostname         string   `form:"ssl_hostname,omitempty"`
        SSLCertHostname     string   `form:"ssl_cert_hostname,omitempty"`
        SSLSNIHostname      string   `form:"ssl_sni_hostname,omitempty"`
        MinTLSVersion       string   `form:"min_tls_version,omitempty"`
        MaxTLSVersion       string   `form:"max_tls_version,omitempty"`
        SSLCiphers          []string `form:"ssl_ciphers,omitempty"`
}

// CreateBackend creates a new Fastly backend.
func (c *Client) CreateBackend(i *CreateBackendInput) (*Backend, error) {
        if i.Service == "" {
                return nil, ErrMissingService
        }

        if i.Version == "" {
                return nil, ErrMissingVersion
        }

        path := fmt.Sprintf("/service/%s/version/%s/backend", i.Service, i.Version)
        resp, err := c.PostForm(path, i, nil)
        if err != nil {
                return nil, err
        }

        var b *Backend
        if err := decodeJSON(&b, resp.Body); err != nil {
                return nil, err
        }
        return b, nil
}

// GetBackendInput is used as input to the GetBackend function.
type GetBackendInput struct {
        // Service is the ID of the service. Version is the specific configuration
        // version. Both fields are required.
        Service string
        Version string

        // Name is the name of the backend to fetch.
        Name string
}

// GetBackend gets the backend configuration with the given parameters.
func (c *Client) GetBackend(i *GetBackendInput) (*Backend, error) {
        if i.Service == "" {
                return nil, ErrMissingService
        }

        if i.Version == "" {
                return nil, ErrMissingVersion
        }

        if i.Name == "" {
                return nil, ErrMissingName
        }

        path := fmt.Sprintf("/service/%s/version/%s/backend/%s", i.Service, i.Version, i.Name)
        resp, err := c.Get(path, nil)
        if err != nil {
                return nil, err
        }

        var b *Backend
        if err := decodeJSON(&b, resp.Body); err != nil {
                return nil, err
        }
        return b, nil
}

// UpdateBackendInput is used as input to the UpdateBackend function.
type UpdateBackendInput struct {
        // Service is the ID of the service. Version is the specific configuration
        // version. Both fields are required.
        Service string
        Version string

        // Name is the name of the backend to update.
        Name string

        NewName             string   `form:"name,omitempty"`
        Address             string   `form:"address,omitempty"`
        Port                uint     `form:"port,omitempty"`
        ConnectTimeout      uint     `form:"connect_timeout,omitempty"`
        MaxConn             uint     `form:"max_conn,omitempty"`
        ErrorThreshold      uint     `form:"error_threshold,omitempty"`
        FirstByteTimeout    uint     `form:"first_byte_timeout,omitempty"`
        BetweenBytesTimeout uint     `form:"between_bytes_timeout,omitempty"`
        AutoLoadbalance     bool     `form:"auto_loadbalance,omitempty"`
        Weight              uint     `form:"weight,omitempty"`
        RequestCondition    string   `form:"request_condition,omitempty"`
        HealthCheck         string   `form:"healthcheck,omitempty"`
        UseSSL              bool     `form:"use_ssl,omitempty"`
        SSLCheckCert        bool     `form:"ssl_check_cert,omitempty"`
        SSLHostname         string   `form:"ssl_hostname,omitempty"`
        SSLCertHostname     string   `form:"ssl_cert_hostname,omitempty"`
        SSLSNIHostname      string   `form:"ssl_sni_hostname,omitempty"`
        MinTLSVersion       string   `form:"min_tls_version,omitempty"`
        MaxTLSVersion       string   `form:"max_tls_version,omitempty"`
        SSLCiphers          []string `form:"ssl_ciphers,omitempty"`
}

// UpdateBackend updates a specific backend.
func (c *Client) UpdateBackend(i *UpdateBackendInput) (*Backend, error) {
        if i.Service == "" {
                return nil, ErrMissingService
        }

        if i.Version == "" {
                return nil, ErrMissingVersion
        }

        if i.Name == "" {
                return nil, ErrMissingName
        }

        path := fmt.Sprintf("/service/%s/version/%s/backend/%s", i.Service, i.Version, i.Name)
        resp, err := c.PutForm(path, i, nil)
        if err != nil {
                return nil, err
        }

        var b *Backend
        if err := decodeJSON(&b, resp.Body); err != nil {
                return nil, err
        }
        return b, nil
}

// DeleteBackendInput is the input parameter to DeleteBackend.
type DeleteBackendInput struct {
        // Service is the ID of the service. Version is the specific configuration
        // version. Both fields are required.
        Service string
        Version string

        // Name is the name of the backend to delete (required).
        Name string
}

// DeleteBackend deletes the given backend version.
func (c *Client) DeleteBackend(i *DeleteBackendInput) error {
        if i.Service == "" {
                return ErrMissingService
        }

        if i.Version == "" {
                return ErrMissingVersion
        }

        if i.Name == "" {
                return ErrMissingName
        }

        path := fmt.Sprintf("/service/%s/version/%s/backend/%s", i.Service, i.Version, i.Name)
        resp, err := c.Delete(path, nil)
        if err != nil {
                return err
        }

        var r *statusResp
        if err := decodeJSON(&r, resp.Body); err != nil {
                return err
        }
        if !r.Ok() {
                return fmt.Errorf("Not Ok")
        }
        return nil
}