// 2026-03-07
// client.go — HTTP-клиент для REST API sless оператора.
// Намеренно изолирован от terraform-plugin-framework — при переносе в nubes
// этот файл кладётся в internal/core/ без изменений.
// Все методы принимают ctx для правильной работы с таймаутами terraform.
package client

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"time"
)

// Client — HTTP-клиент к sless operator REST API.
type Client struct {
	httpClient *http.Client
	endpoint   string
	token      string
}

// New создаёт клиент. endpoint — базовый URL оператора (без trailing slash).
func New(endpoint, token string) *Client {
	return &Client{
		httpClient: &http.Client{Timeout: 30 * time.Second},
		endpoint:   endpoint,
		token:      token,
	}
}

// --- JSON-структуры (зеркало handler/functions.go и handler/triggers.go) ---

// FunctionRequest — тело POST/PUT /v1/namespaces/{ns}/functions[/{name}]
type FunctionRequest struct {
	Name       string            `json:"name"`
	Runtime    string            `json:"runtime"`
	Entrypoint string            `json:"entrypoint,omitempty"`
	MemoryMB   int32             `json:"memory_mb,omitempty"`
	TimeoutSec int32             `json:"timeout_sec,omitempty"`
	Env        map[string]string `json:"env_vars,omitempty"`
}

// FunctionResponse — ответ GET /v1/namespaces/{ns}/functions/{name}
type FunctionResponse struct {
	Name       string            `json:"name"`
	Namespace  string            `json:"namespace"`
	Runtime    string            `json:"runtime"`
	Entrypoint string            `json:"entrypoint"`
	MemoryMB   int32             `json:"memory_mb"`
	TimeoutSec int32             `json:"timeout_sec"`
	Env        map[string]string `json:"env_vars"`
	S3Bucket   string            `json:"s3_bucket"`
	S3Key      string            `json:"s3_key"`
	Phase      string            `json:"phase"`
	ImageRef   string            `json:"image_ref"`
	Message    string            `json:"message"`
}

// TriggerRequest — тело POST /v1/namespaces/{ns}/triggers
type TriggerRequest struct {
	Name        string `json:"name"`
	Type        string `json:"type"`
	FunctionRef string `json:"function"`
	Schedule    string `json:"schedule,omitempty"`
}

// TriggerResponse — ответ GET /v1/namespaces/{ns}/triggers/{name}
type TriggerResponse struct {
	Name        string `json:"name"`
	Namespace   string `json:"namespace"`
	Type        string `json:"type"`
	FunctionRef string `json:"function"`
	Schedule    string `json:"schedule"`
	Active      bool   `json:"active"`
	URL         string `json:"url"`
	Message     string `json:"message"`
}

// --- Внутренний хелпер: выполнить JSON-запрос с Bearer-токеном ---

func (c *Client) doJSON(ctx context.Context, method, url string, body interface{}) (*http.Response, error) {
	var bodyReader io.Reader
	if body != nil {
		data, err := json.Marshal(body)
		if err != nil {
			return nil, fmt.Errorf("marshal request: %w", err)
		}
		bodyReader = bytes.NewReader(data)
	}
	req, err := http.NewRequestWithContext(ctx, method, url, bodyReader)
	if err != nil {
		return nil, err
	}
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}
	req.Header.Set("Authorization", "Bearer "+c.token)
	return c.httpClient.Do(req)
}

// --- Function CRUD ---

// CreateFunction — POST /v1/namespaces/{ns}/functions → 201
func (c *Client) CreateFunction(ctx context.Context, ns string, req FunctionRequest) (*FunctionResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/functions", c.endpoint, ns)
	resp, err := c.doJSON(ctx, http.MethodPost, url, req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("create function: status %d: %s", resp.StatusCode, body)
	}
	var fn FunctionResponse
	return &fn, json.NewDecoder(resp.Body).Decode(&fn)
}

// GetFunction — GET /v1/namespaces/{ns}/functions/{name} → nil если 404
func (c *Client) GetFunction(ctx context.Context, ns, name string) (*FunctionResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/functions/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodGet, url, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil
	}
	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("get function: status %d: %s", resp.StatusCode, body)
	}
	var fn FunctionResponse
	return &fn, json.NewDecoder(resp.Body).Decode(&fn)
}

// UpdateFunction — PUT /v1/namespaces/{ns}/functions/{name} → 200
func (c *Client) UpdateFunction(ctx context.Context, ns, name string, req FunctionRequest) (*FunctionResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/functions/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodPut, url, req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("update function: status %d: %s", resp.StatusCode, body)
	}
	var fn FunctionResponse
	return &fn, json.NewDecoder(resp.Body).Decode(&fn)
}

// DeleteFunction — DELETE /v1/namespaces/{ns}/functions/{name} → 204
func (c *Client) DeleteFunction(ctx context.Context, ns, name string) error {
	url := fmt.Sprintf("%s/v1/namespaces/%s/functions/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodDelete, url, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusNotFound {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("delete function: status %d: %s", resp.StatusCode, body)
	}
	return nil
}

// UploadCode — POST /v1/namespaces/{ns}/functions/{name}/upload (multipart, field=code)
// После вызова оператор начинает kaniko-сборку образа.
func (c *Client) UploadCode(ctx context.Context, ns, name, zipPath string) error {
	f, err := os.Open(zipPath)
	if err != nil {
		return fmt.Errorf("open zip %q: %w", zipPath, err)
	}
	defer f.Close()

	var buf bytes.Buffer
	mw := multipart.NewWriter(&buf)
	fw, err := mw.CreateFormFile("code", filepath.Base(zipPath))
	if err != nil {
		return fmt.Errorf("create form file: %w", err)
	}
	if _, err := io.Copy(fw, f); err != nil {
		return fmt.Errorf("copy zip: %w", err)
	}
	mw.Close()

	url := fmt.Sprintf("%s/v1/namespaces/%s/functions/%s/upload", c.endpoint, ns, name)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, &buf)
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", mw.FormDataContentType())
	req.Header.Set("Authorization", "Bearer "+c.token)

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("upload code: status %d: %s", resp.StatusCode, body)
	}
	return nil
}

// WaitReady опрашивает функцию каждые 5 секунд пока phase != Ready/Failed.
// Нужен после UploadCode — kaniko-сборка занимает ~1 минуту.
func (c *Client) WaitReady(ctx context.Context, ns, name string, timeout time.Duration) (*FunctionResponse, error) {
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		fn, err := c.GetFunction(ctx, ns, name)
		if err != nil {
			return nil, err
		}
		if fn == nil {
			return nil, fmt.Errorf("function %s/%s not found while waiting", ns, name)
		}
		switch fn.Phase {
		case "Ready":
			return fn, nil
		case "Failed":
			return nil, fmt.Errorf("function build failed: %s", fn.Message)
		}
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-time.After(5 * time.Second):
		}
	}
	return nil, fmt.Errorf("timeout waiting for function %s/%s to become Ready", ns, name)
}

// --- Trigger CRUD ---

// CreateTrigger — POST /v1/namespaces/{ns}/triggers → 201
func (c *Client) CreateTrigger(ctx context.Context, ns string, req TriggerRequest) (*TriggerResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/triggers", c.endpoint, ns)
	resp, err := c.doJSON(ctx, http.MethodPost, url, req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("create trigger: status %d: %s", resp.StatusCode, body)
	}
	var tr TriggerResponse
	return &tr, json.NewDecoder(resp.Body).Decode(&tr)
}

// GetTrigger — GET /v1/namespaces/{ns}/triggers/{name} → nil если 404
func (c *Client) GetTrigger(ctx context.Context, ns, name string) (*TriggerResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/triggers/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodGet, url, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil
	}
	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("get trigger: status %d: %s", resp.StatusCode, body)
	}
	var tr TriggerResponse
	return &tr, json.NewDecoder(resp.Body).Decode(&tr)
}

// DeleteTrigger — DELETE /v1/namespaces/{ns}/triggers/{name} → 204
func (c *Client) DeleteTrigger(ctx context.Context, ns, name string) error {
	url := fmt.Sprintf("%s/v1/namespaces/%s/triggers/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodDelete, url, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusNotFound {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("delete trigger: status %d: %s", resp.StatusCode, body)
	}
	return nil
}

// --- Job CRUD ---

// JobRequest — тело POST /v1/namespaces/{ns}/jobs
type JobRequest struct {
	Name        string `json:"name"`
	FunctionRef string `json:"function"`
	EventJSON   string `json:"event_json,omitempty"`
}

// JobResponse — ответ GET /v1/namespaces/{ns}/jobs/{name}
type JobResponse struct {
	Name           string `json:"name"`
	Namespace      string `json:"namespace"`
	FunctionRef    string `json:"function"`
	EventJSON      string `json:"event_json"`
	Phase          string `json:"phase"`
	JobName        string `json:"job_name"`
	StartTime      string `json:"start_time"`
	CompletionTime string `json:"completion_time"`
	Message        string `json:"message"`
}

// CreateJob — POST /v1/namespaces/{ns}/jobs → 201
func (c *Client) CreateJob(ctx context.Context, ns string, req JobRequest) (*JobResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/jobs", c.endpoint, ns)
	resp, err := c.doJSON(ctx, http.MethodPost, url, req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("create job: status %d: %s", resp.StatusCode, body)
	}
	var j JobResponse
	return &j, json.NewDecoder(resp.Body).Decode(&j)
}

// GetJob — GET /v1/namespaces/{ns}/jobs/{name} → nil если 404
func (c *Client) GetJob(ctx context.Context, ns, name string) (*JobResponse, error) {
	url := fmt.Sprintf("%s/v1/namespaces/%s/jobs/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodGet, url, nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusNotFound {
		return nil, nil
	}
	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("get job: status %d: %s", resp.StatusCode, body)
	}
	var j JobResponse
	return &j, json.NewDecoder(resp.Body).Decode(&j)
}

// DeleteJob — DELETE /v1/namespaces/{ns}/jobs/{name} → 204
func (c *Client) DeleteJob(ctx context.Context, ns, name string) error {
	url := fmt.Sprintf("%s/v1/namespaces/%s/jobs/%s", c.endpoint, ns, name)
	resp, err := c.doJSON(ctx, http.MethodDelete, url, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusNotFound {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("delete job: status %d: %s", resp.StatusCode, body)
	}
	return nil
}

// WaitJobDone опрашивает job каждые 5 секунд пока phase не Succeeded или Failed.
// Блокирует terraform apply до завершения джоба.
func (c *Client) WaitJobDone(ctx context.Context, ns, name string, timeout time.Duration) (*JobResponse, error) {
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		j, err := c.GetJob(ctx, ns, name)
		if err != nil {
			return nil, err
		}
		if j == nil {
			return nil, fmt.Errorf("job %s/%s not found while waiting", ns, name)
		}
		switch j.Phase {
		case "Succeeded":
			return j, nil
		case "Failed":
			return nil, fmt.Errorf("job failed: %s", j.Message)
		}
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-time.After(5 * time.Second):
		}
	}
	return nil, fmt.Errorf("timeout waiting for job %s/%s to complete", ns, name)
}