package alert_lifecycle

import (
	"bytes"
	"errors"
	"io"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
)

const maxCloseRequestBytes = 8 * 1024
const closeBodyKey = "bell.lifecycle.close-body"
const closeBodyErrorKey = "bell.lifecycle.close-body-error"

func RedactRequestBody() gin.HandlerFunc {
	return func(c *gin.Context) {
		if c.Request.Method != http.MethodPost || !strings.HasPrefix(c.Request.URL.Path, "/api/v1/bell/alerts/") || !strings.HasSuffix(c.Request.URL.Path, "/close") {
			c.Next()
			return
		}
		body, err := io.ReadAll(io.LimitReader(c.Request.Body, maxCloseRequestBytes+1))
		if err != nil {
			c.Set(closeBodyErrorKey, err)
		} else if len(body) > maxCloseRequestBytes {
			c.Set(closeBodyErrorKey, errors.New("request body too large"))
		} else {
			c.Set(closeBodyKey, body)
		}
		_ = c.Request.Body.Close()
		c.Request.Body = io.NopCloser(bytes.NewReader([]byte(`{"redacted":true}`)))
		c.Next()
	}
}

func restoreCloseBody(c *gin.Context) error {
	if value, ok := c.Get(closeBodyErrorKey); ok {
		return value.(error)
	}
	value, ok := c.Get(closeBodyKey)
	if !ok {
		return errors.New("close request body was not captured")
	}
	c.Request.Body = io.NopCloser(bytes.NewReader(value.([]byte)))
	return nil
}