package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"os"

	"github.com/pkg/errors"
	"github.com/tinkerbell/sandbox/cmd/bump-version/envfile"
	"github.com/tinkerbell/sandbox/cmd/bump-version/git"
	"github.com/tinkerbell/sandbox/cmd/bump-version/image"
)

// Config represents the flags that you can configure
// when running bump-version
type Config struct {
	// CurrentVersionFile is the path of the envfile that
	// contains the current version of Tinkerbell stack.
	// In sandbod it is called current_versions.sh
	CurrentVersionFile string
	// Overwrite switched the output of this program from
	// standard output to the current_versions.sh file.
	Overwrite bool
	// Help prints the help command and exists
	Help bool
}

const help = `
bump-version is an utility that reads and update the current_version.sh file.
It is designed to be used in CI/CD but it works locally as well.

Note:
    * Osie is currently not supported

Examples:
    Prints this -help

    $ bump-version -help

    This is how you will normally run this command.
    bump-version will read the specified current-version-file
    (./current_version.sh), it will clone the various components in memory
    checking the latest commit available in the default branch.

    The command will get and validate that a docker image is available for each
    component and it will print the updated current_version.sh to stdout.

    $ bump-version -current-version-file ./current_versions.sh

    This command does the same as the previous one but it overwrite the content
    of the original current_version file

    $ bump-version -overwrite
`

const headerFile = `#!/bin/bash

# This file is generated by an utility called bump-version in
# tinkerbell/sandbox.
# This file gets used from generate-env.sh but it is also used standalone by
# automation that wants to get the version of the programs currently supported
# in sandbox

`

func main() {
	config := Config{}
	fs := flag.NewFlagSet("bump-version", flag.ContinueOnError)
	fs.BoolVar(&config.Help, "help", false, "Display help command and exit")
	fs.BoolVar(&config.Overwrite, "overwrite", false, "This commands overwrite the current_versions file instead of printing to stdout")
	fs.StringVar(&config.CurrentVersionFile, "current-version-file", "./current_versions.sh", "Load the current_version.sh file where the current Tinkerbell component versions are specified.")
	err := fs.Parse(os.Args[1:])
	if err != nil {
		fmt.Fprint(os.Stderr, help)
		log.Fatalf("Err: %s\n\r", err.Error())
	}
	if config.Help {
		fmt.Fprint(os.Stderr, help)
		os.Exit(0)
	}
	// Read the current_versions envfile
	myEnv, err := envfile.ReadEnvFile(config.CurrentVersionFile)
	if err != nil {
		log.Fatal(errors.Wrap(err, "Impossible to read current_file.sh"))
	}

	tag, err := getImageTagFromRepo("https://github.com/tinkerbell/tink")
	if err != nil {
		log.Fatal(errors.Wrap(err, "Impossible to get image tag from tinkerbell/tink repo"))
	}

	// Set the new versions to the current_versions.sh
	myEnv["TINKERBELL_TINK_SERVER_IMAGE"] = "quay.io/tinkerbell/tink:" + tag
	myEnv["TINKERBELL_TINK_WORKER_IMAGE"] = "quay.io/tinkerbell/tink-worker:" + tag
	myEnv["TINKERBELL_TINK_CLI_IMAGE"] = "quay.io/tinkerbell/tink-cli:" + tag

	tag, err = getImageTagFromRepo("https://github.com/tinkerbell/hegel")
	if err != nil {
		log.Fatal(errors.Wrap(err, "Impossible to get image tag from tinkerbell/hegel repo"))
	}

	myEnv["TINKERBELL_TINK_HEGEL_IMAGE"] = "quay.io/tinkerbell/hegel:" + tag

	tag, err = getImageTagFromRepo("https://github.com/tinkerbell/boots")
	if err != nil {
		log.Fatal(errors.Wrap(err, "Impossible to get image tag from tinkerbell/hegel repo"))
	}

	myEnv["TINKERBELL_TINK_BOOTS_IMAGE"] = "quay.io/tinkerbell/boots:" + tag

	out, err := envfile.Marshal(myEnv)
	if err != nil {
		log.Fatal(errors.Wrap(err, "Impossible to render new current_version envfile"))
	}

	destination := os.Stdout
	// if the overwrite flag is set to true change the output of the command
	// from stdout to the original file
	if config.Overwrite {
		f, err := os.OpenFile(config.CurrentVersionFile, os.O_WRONLY|os.O_TRUNC, 0)
		if err != nil {
			log.Fatal(errors.Wrap(err, "Error overwriting current versions envfile"))
		}
		destination = f
	}

	io.WriteString(destination, headerFile+out+"\n")
}

// getImageTagFromRepo is an utility function that wraps a couple of things
// together that technically we need to repeat for each repo.
func getImageTagFromRepo(repoName string) (string, error) {
	// Clone the specified repository in memory
	repo, err := git.Clone(repoName)
	if err != nil {
		return "", errors.Wrap(err, "Impossible to clone the repository")
	}

	// Get the latest commit from the defautl branch
	latestCommit, err := repo.GetHeadHash()
	if err != nil {
		return "", errors.Wrap(err, "Impossible to get commit from HEAD")
	}

	// Calculate the image tag from a commit sha
	tag, err := image.TagFromSha(latestCommit)
	if err != nil {
		return "", errors.Wrap(err, "Impossible to get image tag from commit")
	}

	return tag, nil

}