package api

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
)

// Server mirrors the backend Server type.
type Server struct {
	Name      string            `json:"name"`
	Type      string            `json:"type"`
	Image     string            `json:"image"`
	Replicas  int32             `json:"replicas"`
	Ready     int32             `json:"ready"`
	Status    string            `json:"status"`
	NodePort  int32             `json:"nodePort,omitempty"`
	Port      int32             `json:"port"`
	EnvVars   map[string]string `json:"envVars"`
	CreatedAt string            `json:"createdAt"`
}

type CreateServerRequest struct {
	Name     string            `json:"name"`
	Type     string            `json:"type"`
	Image    string            `json:"image"`
	Port     int32             `json:"port"`
	NodePort int32             `json:"nodePort,omitempty"`
	EnvVars  map[string]string `json:"envVars"`
}

type UpdateServerRequest struct {
	Image   string            `json:"image,omitempty"`
	EnvVars map[string]string `json:"envVars,omitempty"`
}

// Client is an HTTP client for the games-console backend.
type Client struct {
	BaseURL string
	http    *http.Client
}

func NewClient(baseURL string) *Client {
	return &Client{BaseURL: baseURL, http: &http.Client{}}
}

func (c *Client) ListServers() ([]Server, error) {
	var servers []Server
	return servers, c.get("/api/servers", &servers)
}

func (c *Client) GetServer(name string) (*Server, error) {
	var s Server
	return &s, c.get("/api/servers/"+name, &s)
}

func (c *Client) CreateServer(req CreateServerRequest) (*Server, error) {
	var s Server
	return &s, c.post("/api/servers", req, &s)
}

func (c *Client) UpdateServer(name string, req UpdateServerRequest) (*Server, error) {
	var s Server
	return &s, c.put("/api/servers/"+name, req, &s)
}

func (c *Client) DeleteServer(name string) error {
	return c.delete("/api/servers/" + name)
}

func (c *Client) GetLogs(name string, lines int) (string, error) {
	var resp struct {
		Logs string `json:"logs"`
	}
	return resp.Logs, c.get(fmt.Sprintf("/api/servers/%s/logs?lines=%d", name, lines), &resp)
}

func (c *Client) GetHealth(name string) (map[string]interface{}, error) {
	var resp map[string]interface{}
	return resp, c.get("/api/servers/"+name+"/health", &resp)
}

func (c *Client) Start(name string) error {
	return c.postAction("/api/servers/" + name + "/start")
}

func (c *Client) Stop(name string) error {
	return c.postAction("/api/servers/" + name + "/stop")
}

func (c *Client) Restart(name string) error {
	return c.postAction("/api/servers/" + name + "/restart")
}

// --- HTTP helpers ---

func (c *Client) get(path string, out interface{}) error {
	resp, err := c.http.Get(c.BaseURL + path)
	if err != nil {
		return err
	}
	return decode(resp, out)
}

func (c *Client) post(path string, body interface{}, out interface{}) error {
	b, _ := json.Marshal(body)
	resp, err := c.http.Post(c.BaseURL+path, "application/json", bytes.NewReader(b))
	if err != nil {
		return err
	}
	return decode(resp, out)
}

func (c *Client) postAction(path string) error {
	resp, err := c.http.Post(c.BaseURL+path, "application/json", nil)
	if err != nil {
		return err
	}
	resp.Body.Close()
	if resp.StatusCode >= 400 {
		return fmt.Errorf("server returned %d", resp.StatusCode)
	}
	return nil
}

func (c *Client) put(path string, body interface{}, out interface{}) error {
	b, _ := json.Marshal(body)
	req, _ := http.NewRequest(http.MethodPut, c.BaseURL+path, bytes.NewReader(b))
	req.Header.Set("Content-Type", "application/json")
	resp, err := c.http.Do(req)
	if err != nil {
		return err
	}
	return decode(resp, out)
}

func (c *Client) delete(path string) error {
	req, _ := http.NewRequest(http.MethodDelete, c.BaseURL+path, nil)
	resp, err := c.http.Do(req)
	if err != nil {
		return err
	}
	resp.Body.Close()
	if resp.StatusCode >= 400 {
		return fmt.Errorf("server returned %d", resp.StatusCode)
	}
	return nil
}

func decode(resp *http.Response, out interface{}) error {
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("server error %d: %s", resp.StatusCode, string(body))
	}
	return json.NewDecoder(resp.Body).Decode(out)
}