package release

import (
	"fmt"
	"os"
	"path"
	"strings"

	"github.com/magefile/mage/mg"
	"github.com/magefile/mage/sh"
	"github.com/mholt/archiver"
)

type OS string

const (
	OSAix        OS = "aix"
	OSAndroid    OS = "android"
	OSDarwin     OS = "darwin"
	OSDragonfly  OS = "dragonfly"
	OSFreeBSD    OS = "freebsd"
	OSHurd       OS = "hurd"
	OSIllumos    OS = "illumos"
	OSJavascript OS = "js"
	OSLinux      OS = "linux"
	OSNacl       OS = "nacl"
	OSNetBSD     OS = "netbsd"
	OSOpenBSD    OS = "openbsd"
	OSPlan9      OS = "plan9"
	OSSolaris    OS = "solaris"
	OSWindows    OS = "windows"
	OSZos        OS = "zos"
)

type Arch string

// 386 amd64 amd64p32 arm armbe arm64 arm64be ppc64 ppc64le mips
// mipsle mips64 mips64le mips64p32 mips64p32le ppc riscv riscv64
// s390 s390x sparc sparc64 wasm
// TODO: add missing architectures
const (
	Arch386   Arch = "386"
	ArchAMD64 Arch = "amd64"
	ArchARM   Arch = "arm"
)

type Handler func(env map[string]string, destDir string) error

func EachTarget(handler Handler, opts ...OptionFunc) error {
	options := defaultOptions()
	for _, o := range opts {
		o(options)
	}

	// Clean up existing directory
	if err := sh.Rm(options.BaseDir); err != nil {
		return err
	}

	baseEnv := environment()

	for _, system := range options.Systems {
		for _, arch := range options.Archs {

			dirName := fmt.Sprintf("%s-%s-%s", options.ProjectName, system, arch)
			destDir := path.Join(options.BaseDir, dirName)

			if mg.Verbose() {
				fmt.Printf("Generating release '%s'...\n", dirName)
			}

			// (Re)create destination directory
			if err := os.MkdirAll(destDir, os.ModePerm); err != nil {
				return err
			}

			// Generate Go build-related environment variables
			env := override(
				baseEnv,
				options.Env,
				map[string]string{
					"GOOS":   string(system),
					"GOARCH": string(arch),
				},
			)

			if err := handler(env, destDir); err != nil {
				return err
			}

			archiveType := getArchiveType(system, options.DefaultArchiveType, options.ArchiveTypeMap)
			archiveDest := fmt.Sprintf("%s.%s", destDir, archiveType)

			if mg.Verbose() {
				fmt.Printf("Generating archive '%s'...\n", archiveDest)
			}

			if err := archiver.Archive([]string{destDir}, archiveDest); err != nil {
				return err
			}
		}
	}
	return nil
}

func environment() map[string]string {
	env := make(map[string]string)
	for _, o := range os.Environ() {
		tokens := strings.SplitN(o, "=", 2)
		env[tokens[0]] = tokens[1]
	}
	return env
}

func override(base map[string]string, overrides ...map[string]string) map[string]string {
	env := make(map[string]string)
	for k, v := range base {
		env[k] = v
	}
	for _, o := range overrides {
		for k, v := range o {
			env[k] = v
		}
	}
	return env
}

func getArchiveType(system OS, defaultArchiveType string, archiveTypeMap map[OS]string) string {
	archiveType, exists := archiveTypeMap[system]
	if !exists {
		return defaultArchiveType
	}
	return archiveType
}