package main

import (
  "net/http"
  "sync"

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

type User struct {
  ID    int    `json:"id"`
  Name  string `json:"name"`
  Email string `json:"email"`
}

var (
  users  = []User{
    {ID: 1, Name: "Alice", Email: "alice@example.com"},
    {ID: 2, Name: "Bob", Email: "bob@example.com"},
  }
  nextID = 3
  mu     sync.Mutex
)

func main() {
  r := gin.Default()

  // HTML 模板
  r.LoadHTMLGlob("templates/*.html")
  // 静态资源
  r.Static("/static", "./static")

  r.GET("/", func(c *gin.Context) {
    c.HTML(http.StatusOK, "index.html", gin.H{
      "title":   "Gin Web App",
      "message": "Welcome to Gin with Go",
    })
  })

  r.GET("/ping", func(c *gin.Context) {
    c.JSON(http.StatusOK, gin.H{"message": "pong"})
  })

  r.GET("/users", func(c *gin.Context) {
    mu.Lock()
    defer mu.Unlock()
    c.JSON(http.StatusOK, users)
  })

  r.POST("/users", func(c *gin.Context) {
    var newUser User
    if err := c.ShouldBindJSON(&newUser); err != nil {
      c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
      return
    }
    mu.Lock()
    newUser.ID = nextID
    nextID++
    users = append(users, newUser)
    mu.Unlock()
    c.JSON(http.StatusCreated, newUser)
  })

  r.Run(":8080")
}