package main

import (
    "fmt"
    "encoding/json"
    "os"
    "io/ioutil"
    "io"
)

type Post struct {
    Id int `json:"id"`
    Content string `json:"content"`
    Author Author  `json:"author"`
    Comments []Comment `json:"comments"`
}

type Author struct {
    Id int `json:"id"`
    Name string `json:"name"`
}

type Comment struct {
    Id int `json:"id"`
    Content string `json:"content"`
    Author string `json:"author"`
}

func main()  {
    //创建JSON
    post :=Post {
        Id: 1,
        Content:"Hello World!",
        Author: Author{
            Id: 2,
            Name: "shao tong",
        },
        Comments: []Comment{
            Comment{
                Id:3,
                Content:"Have a great day!",
                Author:"Adam",
            },
            Comment{
                Id:4,
                Content:"How are tyyou today?!",
                Author:"Betty",
            },
        },
    }

    //方法一：
    output,err := json.MarshalIndent(&post,"","\t\t")
    if err != nil {
        fmt.Println("Error marshalling to JSON:",err)
        return
    }
    err = ioutil.WriteFile("post1.json",output,0644)
    if err != nil {
        fmt.Println("Error writing JSON to file:",err)
        return
    }

    //方法二：
    jsonFile,err :=os.Create("post2.json")
    if err != nil {
        fmt.Println("Error creating JSON file:",err)
        return
    }
    encoder :=json.NewEncoder(jsonFile)
    err = encoder.Encode(&post)
    if err != nil {
        fmt.Println("Error encoding JSON to file:",err)
        return
    }

    //分析JSON
    //方法一：
    jsonFile1,err := os.Open("post.json")
    if err != nil {
        fmt.Println("Error opening JSON file",err)
        return
    }
    defer jsonFile1.Close()
    jsonData1,err :=ioutil.ReadAll(jsonFile1)
    if err != nil {
        fmt.Println("Error reading JSON data :",err)
        return
    }
    var post1 Post
    json.Unmarshal(jsonData1, &post1)
    fmt.Println(post1)

    //方法二：
    decoder :=json.NewDecoder(jsonFile1)
    for {
        var post Post
        err :=decoder.Decode(&post)
        if err == io.EOF {
            break
        }
        if err != nil {
            fmt.Println("Error decoding JSON:",err)
            return
        }
        fmt.Println(post)
    }
}