package handlers

import (
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"sproutgate-backend/internal/auth"
	"sproutgate-backend/internal/email"
	"sproutgate-backend/internal/models"
)

func (h *Handler) RequestSecondaryEmail(c *gin.Context) {
	token := bearerToken(c.GetHeader("Authorization"))
	if token == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "missing token"})
		return
	}
	claims, err := auth.ParseToken(h.store.JWTSecret(), h.store.JWTIssuer(), token)
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
		return
	}
	var req secondaryEmailRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}
	emailAddr := strings.TrimSpace(req.Email)
	if emailAddr == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "email is required"})
		return
	}
	user, found, err := h.store.GetUser(claims.Account)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
		return
	}
	if !found {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
		return
	}
	if abortIfUserBanned(c, user) {
		return
	}
	if strings.TrimSpace(user.Email) == emailAddr {
		c.JSON(http.StatusBadRequest, gin.H{"error": "email already used as primary"})
		return
	}
	for _, e := range user.SecondaryEmails {
		if e == emailAddr {
			c.JSON(http.StatusBadRequest, gin.H{"error": "email already verified"})
			return
		}
	}
	code, err := generateVerificationCode()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to generate code"})
		return
	}
	expiresAt := time.Now().Add(10 * time.Minute)
	record := models.SecondaryEmailVerification{
		Account:   user.Account,
		Email:     emailAddr,
		CodeHash:  hashCode(code),
		CreatedAt: models.NowISO(),
		ExpiresAt: expiresAt.Format(time.RFC3339),
	}
	if err := h.store.SaveSecondaryVerification(record); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to save verification"})
		return
	}
	if err := email.SendVerificationEmail(h.store.EmailConfig(), emailAddr, code, 10*time.Minute); err != nil {
		_ = h.store.DeleteSecondaryVerification(user.Account, emailAddr)
		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("failed to send email: %v", err)})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"sent":      true,
		"expiresAt": expiresAt.Format(time.RFC3339),
	})
}

func (h *Handler) VerifySecondaryEmail(c *gin.Context) {
	token := bearerToken(c.GetHeader("Authorization"))
	if token == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "missing token"})
		return
	}
	claims, err := auth.ParseToken(h.store.JWTSecret(), h.store.JWTIssuer(), token)
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
		return
	}
	var req verifySecondaryEmailRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}
	emailAddr := strings.TrimSpace(req.Email)
	code := strings.TrimSpace(req.Code)
	if emailAddr == "" || code == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "email and code are required"})
		return
	}
	record, found, err := h.store.GetSecondaryVerification(claims.Account, emailAddr)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load verification"})
		return
	}
	if !found {
		c.JSON(http.StatusBadRequest, gin.H{"error": "verification not found"})
		return
	}
	expiresAt, err := time.Parse(time.RFC3339, record.ExpiresAt)
	if err != nil || time.Now().After(expiresAt) {
		_ = h.store.DeleteSecondaryVerification(claims.Account, emailAddr)
		c.JSON(http.StatusBadRequest, gin.H{"error": "verification code expired"})
		return
	}
	if !verifyCode(code, record.CodeHash) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid verification code"})
		return
	}
	user, found, err := h.store.GetUser(claims.Account)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to load user"})
		return
	}
	if !found {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "user not found"})
		return
	}
	if abortIfUserBanned(c, user) {
		return
	}
	for _, e := range user.SecondaryEmails {
		if e == emailAddr {
			_ = h.store.DeleteSecondaryVerification(claims.Account, emailAddr)
			c.JSON(http.StatusOK, gin.H{"verified": true, "user": user.OwnerPublic()})
			return
		}
	}
	user.SecondaryEmails = append(user.SecondaryEmails, emailAddr)
	if err := h.store.SaveUser(user); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to save user"})
		return
	}
	_ = h.store.DeleteSecondaryVerification(claims.Account, emailAddr)
	c.JSON(http.StatusOK, gin.H{"verified": true, "user": user.OwnerPublic()})
}