// Copyright 2023 Woodpecker Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// cSpell:ignore ERRORLEVEL

package local

import (
	"fmt"
	"os"
	"os/exec"
	"strings"

	"al.essio.dev/pkg/shellescape"
)

func (e *local) genCmdByShell(shell string, cmdList []string) (args []string, err error) {
	if len(cmdList) == 0 {
		return nil, ErrNoCmdSet
	}

	script := ""
	for _, cmd := range cmdList {
		script += fmt.Sprintf("echo %s\n%s\n", strings.TrimSpace(shellescape.Quote("+ "+cmd)), cmd)
	}
	script = strings.TrimSpace(script)

	shell = strings.TrimSuffix(strings.ToLower(shell), ".exe")
	switch shell {
	default:
		// assume posix shell
		if err := probeShellIsPosix(shell); err != nil {
			return nil, err
		}
		fallthrough
		// normal posix shells
	case "sh", "bash", "zsh":
		return []string{"-e", "-c", script}, nil
	case "":
		return nil, ErrNoShellSet
	case "cmd":
		script := "@SET PROMPT=$\n"
		for _, cmd := range cmdList {
			quotedCmd := strings.TrimSpace(shellescape.Quote(cmd))
			// As cmd echo does not allow strings with newlines we need to replace them ...
			quotedCmd = strings.ReplaceAll(quotedCmd, "\n", "\\n")
			// Also the shellescape.Quote fail with any | or & char and wrapping them in quotes again can be bypassed
			// by just leaving an string halve quoted we just replace them with symbolic representations
			quotedCmd = strings.ReplaceAll(quotedCmd, "&", "\\AND")
			quotedCmd = strings.ReplaceAll(quotedCmd, "|", "\\OR")

			script += fmt.Sprintf("@echo + %s\n", quotedCmd)
			script += fmt.Sprintf("@%s\n", cmd)
			script += "@IF NOT %ERRORLEVEL% == 0 exit %ERRORLEVEL%\n"
		}
		cmd, err := os.CreateTemp(e.tempDir, "*.cmd")
		if err != nil {
			return nil, err
		}
		defer cmd.Close()
		if _, err := cmd.WriteString(script); err != nil {
			return nil, err
		}
		return []string{"/c", cmd.Name()}, nil
	case "fish":
		script := ""
		for _, cmd := range cmdList {
			script += fmt.Sprintf("echo %s\n%s || exit $status\n", strings.TrimSpace(shellescape.Quote("+ "+cmd)), cmd)
		}
		return []string{"-c", script}, nil
	case "nu":
		return []string{"--commands", script}, nil
	case "powershell", "pwsh":
		// cspell:disable-next-line
		return []string{"-noprofile", "-noninteractive", "-c", "$ErrorActionPreference = \"Stop\"; " + script}, nil
	}
}

// before we generate a generic posix shell we test.
func probeShellIsPosix(shell string) error {
	script := `x=1 && [ "$x" = "1" ] && command -v test >/dev/null && printf ok`

	cmd := exec.Command(shell, "-c", script)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return &ErrNoPosixShell{Shell: shell, Err: err}
	}

	if strings.TrimSpace(string(output)) != "ok" {
		return &ErrNoPosixShell{Shell: shell, Err: fmt.Errorf("unexpected output returned: %q", string(output))}
	}

	return nil
}