package core_test

import (
	"bytes"
	"io"
	"os"
	"path/filepath"
	"testing"

	"git.hrafn.xyz/aether/gosick/internal/homesick/core"
	"github.com/stretchr/testify/require"
	"github.com/stretchr/testify/suite"
)

type RcSuite struct {
	suite.Suite
	tmpDir   string
	homeDir  string
	reposDir string
	stdout   *bytes.Buffer
	stderr   *bytes.Buffer
	app      *core.App
}

func TestRcSuite(t *testing.T) {
	suite.Run(t, new(RcSuite))
}

func (s *RcSuite) SetupTest() {
	s.tmpDir = s.T().TempDir()
	s.homeDir = filepath.Join(s.tmpDir, "home")
	s.reposDir = filepath.Join(s.homeDir, ".homesick", "repos")
	require.NoError(s.T(), os.MkdirAll(s.reposDir, 0o755))

	s.stdout = &bytes.Buffer{}
	s.stderr = &bytes.Buffer{}
	s.app = &core.App{
		HomeDir:  s.homeDir,
		ReposDir: s.reposDir,
		Stdout:   s.stdout,
		Stderr:   s.stderr,
	}
}

func (s *RcSuite) createCastle(name string) string {
	castleRoot := filepath.Join(s.reposDir, name)
	require.NoError(s.T(), os.MkdirAll(castleRoot, 0o755))
	return castleRoot
}

var _ io.Writer

// TestRc_UnknownCastleReturnsError ensures Rc returns an error when the
// castle directory does not exist.
func (s *RcSuite) TestRc_UnknownCastleReturnsError() {
	err := s.app.Rc("nonexistent")
	require.Error(s.T(), err)
}

// TestRc_NoScriptsAndNoHomesickrc is a no-op when neither .homesick.d nor
// .homesickrc are present.
func (s *RcSuite) TestRc_NoScriptsAndNoHomesickrcIsNoop() {
	s.createCastle("dotfiles")
	require.NoError(s.T(), s.app.Rc("dotfiles"))
}

// TestRc_ExecutesScriptsInSortedOrder verifies that executable scripts inside
// .homesick.d are run in lexicographic (sorted) order.
func (s *RcSuite) TestRc_ExecutesScriptsInSortedOrder() {
	castleRoot := s.createCastle("dotfiles")
	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	orderFile := filepath.Join(s.tmpDir, "order.txt")
	scriptA := filepath.Join(homesickD, "10_a.sh")
	scriptB := filepath.Join(homesickD, "20_b.sh")

	require.NoError(s.T(), os.WriteFile(scriptA, []byte("#!/bin/sh\necho a >> "+orderFile+"\n"), 0o755))
	require.NoError(s.T(), os.WriteFile(scriptB, []byte("#!/bin/sh\necho b >> "+orderFile+"\n"), 0o755))

	require.NoError(s.T(), s.app.Rc("dotfiles"))

	content, err := os.ReadFile(orderFile)
	require.NoError(s.T(), err)
	require.Equal(s.T(), "a\nb\n", string(content))
}

// TestRc_SkipsNonExecutableFiles ensures that files without the executable bit
// are not run.
func (s *RcSuite) TestRc_SkipsNonExecutableFiles() {
	castleRoot := s.createCastle("dotfiles")
	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	notExec := filepath.Join(homesickD, "10_script.sh")
	// Write a script that would exit 1 if actually run — verify it is skipped.
	require.NoError(s.T(), os.WriteFile(notExec, []byte("#!/bin/sh\nexit 1\n"), 0o644))

	require.NoError(s.T(), s.app.Rc("dotfiles"))
}

// TestRc_HomesickrcCreatesRubyWrapper verifies that a .homesickrc file causes
// a Ruby wrapper to be written into .homesick.d before execution.
func (s *RcSuite) TestRc_HomesickrcCreatesRubyWrapper() {
	castleRoot := s.createCastle("dotfiles")
	homesickRc := filepath.Join(castleRoot, ".homesickrc")
	require.NoError(s.T(), os.WriteFile(homesickRc, []byte("# ruby setup code\n"), 0o644))

	require.NoError(s.T(), s.app.Rc("dotfiles"))

	wrapperPath := filepath.Join(castleRoot, ".homesick.d", "00_homesickrc.rb")
	require.FileExists(s.T(), wrapperPath)

	info, err := os.Stat(wrapperPath)
	require.NoError(s.T(), err)
	require.NotZero(s.T(), info.Mode()&0o111, "wrapper must be executable")

	content, err := os.ReadFile(wrapperPath)
	require.NoError(s.T(), err)
	require.Contains(s.T(), string(content), ".homesickrc")
}

// TestRc_HomesickrcWrapperRunsBeforeOtherScripts ensures the wrapper file
// (00_homesickrc.rb) sorts before typical user scripts and is present in
// .homesick.d after Rc returns.
func (s *RcSuite) TestRc_HomesickrcWrapperCreatedBeforeExecution() {
	castleRoot := s.createCastle("dotfiles")
	homesickRc := filepath.Join(castleRoot, ".homesickrc")
	require.NoError(s.T(), os.WriteFile(homesickRc, []byte("# ruby setup code\n"), 0o644))

	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	// A sentinel script that records whether the wrapper already exists.
	orderFile := filepath.Join(s.tmpDir, "check.txt")
	sentinel := filepath.Join(homesickD, "50_check.sh")
	wrapperPath := filepath.Join(homesickD, "00_homesickrc.rb")
	require.NoError(s.T(), os.WriteFile(sentinel, []byte(
		"#!/bin/sh\n[ -f "+wrapperPath+" ] && echo present >> "+orderFile+"\n",
	), 0o755))

	require.NoError(s.T(), s.app.Rc("dotfiles"))

	content, err := os.ReadFile(orderFile)
	require.NoError(s.T(), err)
	require.Equal(s.T(), "present\n", string(content))
}

// TestRc_FailingScriptReturnsError ensures that a non-zero exit from a script
// propagates as an error.
func (s *RcSuite) TestRc_FailingScriptReturnsError() {
	castleRoot := s.createCastle("dotfiles")
	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	failing := filepath.Join(homesickD, "10_fail.sh")
	require.NoError(s.T(), os.WriteFile(failing, []byte("#!/bin/sh\nexit 42\n"), 0o755))

	err := s.app.Rc("dotfiles")
	require.Error(s.T(), err)
}

// TestRc_ScriptOutputForwarded verifies that stdout and stderr from scripts
// are forwarded to the App's writers.
func (s *RcSuite) TestRc_ScriptOutputForwarded() {
	castleRoot := s.createCastle("dotfiles")
	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	script := filepath.Join(homesickD, "10_output.sh")
	require.NoError(s.T(), os.WriteFile(script, []byte("#!/bin/sh\necho hello\necho world >&2\n"), 0o755))

	require.NoError(s.T(), s.app.Rc("dotfiles"))
	require.Contains(s.T(), s.stdout.String(), "hello")
	require.Contains(s.T(), s.stderr.String(), "world")
}

// TestRc_ScriptsRunWithCwdSetToCastleRoot verifies scripts execute with the
// castle root as the working directory.
func (s *RcSuite) TestRc_ScriptsRunWithCwdSetToCastleRoot() {
	castleRoot := s.createCastle("dotfiles")
	homesickD := filepath.Join(castleRoot, ".homesick.d")
	require.NoError(s.T(), os.MkdirAll(homesickD, 0o755))

	script := filepath.Join(homesickD, "10_pwd.sh")
	require.NoError(s.T(), os.WriteFile(script, []byte("#!/bin/sh\npwd\n"), 0o755))

	require.NoError(s.T(), s.app.Rc("dotfiles"))
	require.Contains(s.T(), s.stdout.String(), castleRoot)
}