# We use a simple Go program to report many Go versions.
# The program also errors on any command other than "go version",
# which saves us having to rebuild main.go many times.
go build -o .bin/go$exe ./fakego
env PATH=${WORK}/.bin${:}${PATH}

# An empty go version.
env TOOLCHAIN_GOVERSION=''
! exec garble build
stderr 'Go version is too old; please upgrade to go1\.22 or newer'

# We should error on a devel version that's too old.
# Note that they lacked the "goN.M-" prefix.
env TOOLCHAIN_GOVERSION='devel +afb5fca Sun Aug 07 00:00:00 2020 +0000'
! exec garble build
stderr 'Go version is too old; please upgrade to go1\.22 or newer'

# Another form of old version; with an old "goN.M-" prefix.
env TOOLCHAIN_GOVERSION='devel go1.15-afb5fca Sun Aug 07 00:00:00 2020 +0000'
! exec garble build
stderr 'Go version "devel go1\.15-.*2020.*" is too old; please upgrade to go1\.22'

# A current devel version should be fine.
# Note that we don't look at devel version timestamps.
env GARBLE_TEST_GOVERSION='go1.22'
env TOOLCHAIN_GOVERSION='devel go1.22-ad97d204f0 Sun Sep 12 16:46:58 2023 +0000'
! exec garble build
stderr 'mocking the real build'

# We should error on a stable version that's too old.
env TOOLCHAIN_GOVERSION='go1.14'
! exec garble build
stderr 'Go version "go1\.14" is too old; please upgrade to go1\.22 or newer'

# We should accept a future stable version.
# Note that we need to bump the version of Go that supposedly built it, too.
env GARBLE_TEST_GOVERSION='go1.28.2'
env TOOLCHAIN_GOVERSION='go1.28.2'
! exec garble build
stderr 'mocking the real build'

# We should accept custom devel strings.
env TOOLCHAIN_GOVERSION='devel go1.23-somecustomversion'
! exec garble build
stderr 'mocking the real build'

# The current toolchain may be older than the one that built garble.
env GARBLE_TEST_GOVERSION='go1.23'
env TOOLCHAIN_GOVERSION='go1.22.3'
! exec garble build
stderr 'mocking the real build'

# The current toolchain may be equal to the one that built garble.
env GARBLE_TEST_GOVERSION='devel go1.22-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
env TOOLCHAIN_GOVERSION='devel go1.22-6673d5d701 Sun Mar 20 16:05:03 2023 +0000'
! exec garble build
stderr 'mocking the real build'

# The current toolchain must not be newer than the one that built garble.
env GARBLE_TEST_GOVERSION='go1.18'
env TOOLCHAIN_GOVERSION='go1.22.1'
! exec garble build
stderr 'garble was built with "go1\.18" and can''t be used with the newer "go1\.22\.1"; rebuild '

# We'll error even if the difference is a minor (bugfix) level.
# In practice it probably wouldn't matter, but in theory it could still lead to tricky bugs.
env GARBLE_TEST_GOVERSION='go1.22.11'
env TOOLCHAIN_GOVERSION='go1.22.14'
! exec garble build
stderr 'garble was built with "go1\.22\.11" and can''t be used with the newer "go1\.22\.14"; rebuild '

# If garble builds itself and is then used, it won't know what version built it.
# As a fallback, we drop the comparison against the toolchain's version.
env GARBLE_TEST_GOVERSION='bogus version'
env TOOLCHAIN_GOVERSION='go1.22.3'
! exec garble build
stderr 'mocking the real build'
-- go.mod --
module test/main

go 1.22
-- main.go --
package main

func main() {}

-- fakego/main.go --
package main

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

func main() {
	if len(os.Args) > 0 && os.Args[1] == "env" {
		enc, _ := json.Marshal(struct{
			GOVERSION string
		} {
			GOVERSION: os.Getenv("TOOLCHAIN_GOVERSION"),
		})
		fmt.Printf("%s\n", enc)
		return
	}
	fmt.Fprintln(os.Stderr, "mocking the real build")
	os.Exit(1)
}