package main

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
    "strings"
)

const INDENT = "    "

type BaseWebHook struct {
    Secret string `json:"secret"`
}

type Push struct {
    BaseWebHook
    Ref        string     `json:"ref"`
    Before     string     `json:"before"`
    After      string     `json:"after"`
    CompareUrl string     `json:"compare_url"`
    Commits    []Commit   `json:"commits"`
    Repository Repository `json:"repository"`
    Pusher     RepoUser   `json:"pusher"`
    Sender     RepoUser   `json:"sender"`
}

type RepoUser struct {
    ID        float64 `json:"id"`
    Login     string  `json:"login"`
    FullName  string  `json:"full_name"`
    Email     string  `json:"email"`
    AvatarUrl string  `json:"avatar_url"`
    Language  string  `json:"language"`
    Username  string  `json:"username"`
}

type Repository struct {
    ID              float64         `json:"id"`
    Owner           RepoUser        `json:"owner"`
    Name            string          `json:"name"`
    FullName        string          `json:"full_name"`
    Description     string          `json:"description"`
    Empty           bool            `json:"empty"`
    Private         bool            `json:"private"`
    Fork            bool            `json:"fork"`
    Parent          string          `json:"parent"`
    Mirror          bool            `json:"mirror"`
    Size            float64         `json:"size"`
    HtmlUrl         string          `json:"html_url"`
    SshUrl          string          `json:"ssh_url"`
    CloneUrl        string          `json:"clone_url"`
    Website         string          `json:"website"`
    StarsCount      float64         `json:"stars_count"`
    ForksCount      float64         `json:"forks_count"`
    WatchersCount   float64         `json:"watchers_count"`
    OpenIssuesCount float64         `json:"open_issues_count"`
    DefaultBranch   string          `json:"default_branch"`
    Archived        bool            `json:"archived"`
    CreatedAt       string          `json:"created_at"`
    UpdatedAt       string          `json:"updated_at"`
    Permissions     RepoPermissions `json:"permissions"`
}

type RepoPermissions struct {
    Admin bool
    Push  bool
    Pull  bool
}

type Commit struct {
    Hash         string      `json:"id"`
    Message      string      `json:"message"`
    Author       Person      `json:"author"`
    Committer    Person      `json:"committer"`
    Verification interface{} `json:"verification"`
    Timestamp    string      `json:"timestamp"`
}

type Person struct {
    Name     string `json:"name"`
    Email    string `json:"email"`
    Username string `json:"username"`
}

func ListenForWebHook(config Config) {
    http.HandleFunc("/", handleWebHook)

    err := http.ListenAndServe(config.BindHost+":"+config.BindPort, nil)

    if err != nil {
        fmt.Println(err)
    }
}

func handleWebHook(writer http.ResponseWriter, request *http.Request) {
    defer request.Body.Close()
    data, err := ioutil.ReadAll(request.Body)
    if err != nil {
        panic(err)
    }

    switch eventType := request.Header.Get("X-Gitea-Event"); eventType {
    case "push":
        handlePush(data)

    case "":
        // Not a gitea event.
        fmt.Printf("Got a non-event HTTP request %+v\n", request)
        return

    default:
        fmt.Printf("Unknown event type: %q\n", eventType)
        handleUnknown(data)
        return
    }
}

func printSep() {
    fmt.Println("---")
}

func handleUnknown(data []byte) {
    printSep()
    fmt.Println(string(data))
}

func handlePush(data []byte) {
    printSep()
    pushData := Push{}
    json.Unmarshal(data, &pushData)
    fmt.Printf(
        "Got a push for repo %q owned by %q. Pushed by %q (%q)\n",
        pushData.Repository.FullName,
        pushData.Repository.Owner.Login,
        pushData.Pusher.Login,
        pushData.Pusher.Email,
    )

    for _, commit := range pushData.Commits {
        fmt.Println(INDENT + "--")
        fmt.Printf(
            INDENT+"Commit added by %q (%q), made by %q (%q), with hash %q and message:\n",
            commit.Committer.Name,
            commit.Committer.Email,
            commit.Author.Name,
            commit.Author.Email,
            commit.Hash,
        )

        msg := strings.Replace(commit.Message, "\n", strings.Repeat(INDENT, 2)+"\n", -1)
        fmt.Println(strings.Repeat(INDENT, 2) + msg)
    }

}