// Package tools provides a shared HTTP client for external API calls.
package tools

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

// APIClient is a reusable HTTP client for external APIs.
// All outbound calls go through this — no hidden network access.
type APIClient struct {
	client  *http.Client
	baseURL string
	apiKey  string
}

// NewAPIClient creates a client for an external API.
func NewAPIClient(baseURL, apiKey string) *APIClient {
	return &APIClient{
		client: &http.Client{
			Timeout: 10 * time.Second,
		},
		baseURL: strings.TrimRight(baseURL, "/"),
		apiKey:  apiKey,
	}
}

// Get performs a GET request with query parameters.
func (c *APIClient) Get(path string, params map[string]string) ([]byte, error) {
	u, err := url.Parse(c.baseURL + path)
	if err != nil {
		return nil, err
	}

	q := u.Query()
	for k, v := range params {
		q.Set(k, v)
	}
	if c.apiKey != "" {
		q.Set("key", c.apiKey)
	}
	u.RawQuery = q.Encode()

	resp, err := c.client.Get(u.String())
	if err != nil {
		return nil, fmt.Errorf("api: GET %s: %w", path, err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("api: GET %s returned %d: %s", path, resp.StatusCode, string(body[:min(200, len(body))]))
	}

	return body, nil
}

// GetJSON performs a GET and decodes the response as JSON.
func (c *APIClient) GetJSON(path string, params map[string]string, result interface{}) error {
	body, err := c.Get(path, params)
	if err != nil {
		return err
	}
	return json.Unmarshal(body, result)
}

// PostJSON performs a POST with JSON body and decodes the response.
func (c *APIClient) PostJSON(path string, params map[string]string, reqBody, result interface{}) error {
	u, err := url.Parse(c.baseURL + path)
	if err != nil {
		return err
	}

	q := u.Query()
	for k, v := range params {
		q.Set(k, v)
	}
	if c.apiKey != "" {
		q.Set("key", c.apiKey)
	}
	u.RawQuery = q.Encode()

	bodyBytes, err := json.Marshal(reqBody)
	if err != nil {
		return err
	}

	resp, err := c.client.Post(u.String(), "application/json", strings.NewReader(string(bodyBytes)))
	if err != nil {
		return fmt.Errorf("api: POST %s: %w", path, err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("api: POST %s returned %d: %s", path, resp.StatusCode, string(respBody[:min(200, len(respBody))]))
	}

	return json.Unmarshal(respBody, result)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}