package api

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"log"
	"net/http"
	"os"
	"resource-manager/security"
	"strings"
	"time"
)

func Auth() gin.HandlerFunc {
	basicAuth, hasBasicAuth := os.LookupEnv("BASIC_AUTH_CREDENTIALS")
	var apiAuths []string
	if list, hasApiAuth := os.LookupEnv("API_CREDENTIALS"); hasApiAuth {
		apiAuths = strings.Split(list, ",")
	}

	return func(c *gin.Context) {
		if rawToken := c.Query("token"); rawToken != "" {
			token, err := security.ParseToken(rawToken)
			if err != nil {
				abort(c, nil, http.StatusUnauthorized, "invalid token")
				return
			}
			c.Set("secure", "token")
			c.Set("path", token.Path)
			return
		}
		authHeader := c.GetHeader("Authorization")
		if strings.HasPrefix(authHeader, "Basic ") && hasBasicAuth {
			if strings.TrimPrefix(authHeader, "Basic ") == basicAuth {
				c.Set("secure", security.TypeBasic)
				return
			}
		}
		if strings.HasPrefix(authHeader, "Api ") && hasBasicAuth {
			key := strings.TrimPrefix(authHeader, "Api ")
			if hasValidApiKey(apiAuths, key) {
				c.Set("secure", security.TypeApi)
				return
			}
		}
		abort(c, nil, http.StatusUnauthorized, "missing auth")
	}
}

func Secure(types ...security.Type) gin.HandlerFunc {
	return func(c *gin.Context) {
		value, exists := c.Get("secure")
		if !exists {
			abort(c, nil, http.StatusUnauthorized, "missing auth")
		} else {
			securityType := value.(security.Type)
			for _, t := range types {
				if t == securityType {
					return
				}
			}
			abort(c, nil, http.StatusUnauthorized, fmt.Sprintf("bad security: received %s type", securityType))
		}
	}
}

func hasValidApiKey(auths []string, key string) bool {
	for _, a := range auths {
		if a == key {
			return true
		}
	}
	return false
}

func abort(c *gin.Context, err error, statusCode int, message string) {
	log.Printf("Aborted with error: %v", err)
	c.AbortWithStatusJSON(statusCode, gin.H{"status": statusCode, "created": time.Now(), "message": message})
}