package auth

import (
	"net/http"
	"strings"

	"photum-backend/internal/config"

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

func AuthMiddleware(cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		var tokenString string

		if authHeader != "" {
			parts := strings.Split(authHeader, " ")
			if len(parts) == 2 && parts[0] == "Bearer" {
				tokenString = parts[1]
			} else if len(parts) == 1 && parts[0] != "" {
				tokenString = parts[0]
			} else {
				c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid authorization header format"})
				return
			}
		} else {
			// Try to get from cookie
			cookie, err := c.Cookie("access_token")
			if err == nil && cookie != "" {
				tokenString = cookie
			} else {
				c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "authorization header required"})
				return
			}
		}
		claims, err := ValidateToken(tokenString, cfg.JwtAccessSecret)
		if err != nil {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
			return
		}

		c.Set("userID", claims.UserID.String())
		c.Set("role", claims.Role)
		c.Set("regioes", claims.Regioes)

		// Add Vary header to correctly handle browser caching based on region
		c.Header("Vary", "x-regiao")
		c.Header("Cache-Control", "no-cache, no-store, must-revalidate")
		c.Header("Pragma", "no-cache")
		c.Header("Expires", "0")

		// Region Logic
		requestedRegion := c.GetHeader("x-regiao")
		if requestedRegion == "" {
			// Default to first permitted region (usually SP)
			if len(claims.Regioes) > 0 {
				requestedRegion = claims.Regioes[0]
			} else {
				requestedRegion = "SP" // Fallback
			}
		}

		// Validate access
		allowed := false
		for _, r := range claims.Regioes {
			if r == requestedRegion {
				allowed = true
				break
			}
		}

		// If user has no regions (legacy) or empty list, maybe allow SP if not specified?
		// Or strictly enforce. Enforcing strictly is safer.
		if !allowed && len(claims.Regioes) > 0 {
			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "acesso negado a esta região"})
			return
		}
		if len(claims.Regioes) == 0 {
			// Legacy user handling - allow SP if they have no list?
			// Schema default is ['SP'], so new users/migrated users should have it.
			// Only broken data would fail.
			if requestedRegion == "SP" {
				allowed = true
			}
		}

		if !allowed {
			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "acesso negado a esta região"})
			return
		}

		c.Set("regiao", requestedRegion)
		c.Next()
	}
}

// RequireWriteAccess middleware to prevent AGENDA_VIEWER from modifying data
func RequireWriteAccess() gin.HandlerFunc {
	return func(c *gin.Context) {
		role := c.GetString("role")
		if role == "AGENDA_VIEWER" {
			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "você não tem permissão para modificar dados"})
			return
		}
		c.Next()
	}
}

// RequireLogisticsAccess middleware to prevent AGENDA_VIEWER from accessing logistics
func RequireLogisticsAccess() gin.HandlerFunc {
	return func(c *gin.Context) {
		role := c.GetString("role")
		if role == "AGENDA_VIEWER" {
			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "você não tem permissão para acessar logística"})
			return
		}
		c.Next()
	}
}
