package middleware

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

	sessionHelper "synlotto-website/internal/helpers/session"
	"synlotto-website/internal/platform/bootstrap"
	"synlotto-website/internal/platform/sessionkeys"

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

// Tracks idle timeout using LastActivity; redirects on timeout.
func AuthMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		app := c.MustGet("app").(*bootstrap.App)
		sm := app.SessionManager
		ctx := c.Request.Context()

		if v := sm.Get(ctx, sessionkeys.LastActivity); v != nil {
			if last, ok := v.(time.Time); ok && time.Since(last) > sm.Lifetime {
				_ = sm.RenewToken(ctx)
				sm.Put(ctx, sessionkeys.Flash, "Your session has timed out.")
				c.Redirect(http.StatusSeeOther, "/account/login")
				c.Abort()
				return
			}
		}

		sm.Put(ctx, sessionkeys.LastActivity, time.Now().UTC())
		c.Next()
	}
}

// Optional remember-me using selector:verifier token pair.
func RememberMiddleware(app *bootstrap.App) gin.HandlerFunc {
	return func(c *gin.Context) {
		sm := app.SessionManager
		ctx := c.Request.Context()

		// Already logged in? Skip.
		if sm.Exists(ctx, sessionkeys.UserID) {
			c.Next()
			return
		}

		cookie, err := c.Request.Cookie(app.Config.Session.RememberCookieName)
		if err != nil {
			c.Next()
			return
		}

		parts := strings.SplitN(cookie.Value, ":", 2)
		if len(parts) != 2 {
			c.Next()
			return
		}
		selector, verifier := parts[0], parts[1]

		userID, hash, expires, revokedAt, err := sessionHelper.FindToken(app.DB, selector)
		if err != nil || revokedAt != nil || time.Now().After(expires) {
			c.Next()
			return
		}

		if sessionHelper.HashVerifier(verifier) != hash {
			// Tampered token – revoke for safety.
			_ = sessionHelper.RevokeToken(app.DB, selector)
			c.Next()
			return
		}

		// Success → create fresh SCS session
		_ = sm.RenewToken(ctx)
		sm.Put(ctx, sessionkeys.UserID, userID)
		sm.Put(ctx, sessionkeys.LastActivity, time.Now().UTC())

		c.Next()
	}
}

// Blocks anonymous users; redirects to login.
func RequireAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		app := c.MustGet("app").(*bootstrap.App)
		sm := app.SessionManager

		if sm.GetInt(c.Request.Context(), sessionkeys.UserID) == 0 {
			c.Redirect(http.StatusSeeOther, "/account/login")
			c.Abort()
			return
		}
		c.Next()
	}
}