// Don't run these on Windows, because newline handling means they don't pass.

//go:build !windows

package interp_test

import (
	"fmt"
	"strings"

	"github.com/benhoyt/goawk/interp"
	"github.com/benhoyt/goawk/parser"
)

func Example() {
	input := strings.NewReader("foo bar\n\nbaz buz")
	err := interp.Exec("$0 { print $1 }", " ", input, nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	// Output:
	// foo
	// baz
}

func Example_fieldsep() {
	// Use ',' as the field separator
	input := strings.NewReader("1,2\n3,4")
	err := interp.Exec("{ print $1, $2 }", ",", input, nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	// Output:
	// 1 2
	// 3 4
}

func Example_program() {
	src := "{ print NR, tolower($0) }"
	input := "A\naB\nAbC"

	prog, err := parser.ParseProgram([]byte(src), nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	config := &interp.Config{
		Stdin: strings.NewReader(input),
		Vars:  []string{"OFS", ":"},
	}
	_, err = interp.ExecProgram(prog, config)
	if err != nil {
		fmt.Println(err)
		return
	}
	// Output:
	// 1:a
	// 2:ab
	// 3:abc
}

func Example_funcs() {
	src := `BEGIN { print sum(), sum(1), sum(2, 3, 4), repeat("xyz", 3) }`

	parserConfig := &parser.ParserConfig{
		Funcs: map[string]any{
			"sum": func(args ...float64) float64 {
				sum := 0.0
				for _, a := range args {
					sum += a
				}
				return sum
			},
			"repeat": strings.Repeat,
		},
	}
	prog, err := parser.ParseProgram([]byte(src), parserConfig)
	if err != nil {
		fmt.Println(err)
		return
	}
	interpConfig := &interp.Config{
		Funcs: parserConfig.Funcs,
	}
	_, err = interp.ExecProgram(prog, interpConfig)
	if err != nil {
		fmt.Println(err)
		return
	}
	// Output:
	// 0 1 9 xyzxyzxyz
}

func Example_new() {
	// We'll execute this program multiple times on different inputs.
	src := `{ print $1, x, $3; x++ }`

	// Parse the program and set up the interpreter.
	prog, err := parser.ParseProgram([]byte(src), nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	interpreter, err := interp.New(prog)
	if err != nil {
		fmt.Println(err)
		return
	}

	// Run it once on one input.
	_, err = interpreter.Execute(&interp.Config{
		Stdin:   strings.NewReader("one two three"),
		Environ: []string{}, // avoid calling os.Environ each time
	})
	if err != nil {
		fmt.Println(err)
		return
	}

	// Reset variables and run it again efficiently on a different input (this
	// could be from a completely different data source).
	interpreter.ResetVars()
	_, err = interpreter.Execute(&interp.Config{
		Stdin:   strings.NewReader("a b c\nd e f\n"),
		Environ: []string{},
	})
	if err != nil {
		fmt.Println(err)
		return
	}

	// Run it on another input, this time without resetting variables.
	_, err = interpreter.Execute(&interp.Config{
		Stdin:   strings.NewReader("x y z"),
		Environ: []string{},
	})
	if err != nil {
		fmt.Println(err)
		return
	}

	// Output:
	// one  three
	// a  c
	// d 1 f
	// x 2 z
}

func Example_csv() {
	src := `{ total += @"amount" } END { print total }`
	input := `# comment
name,amount
Bob,17.50
Jill,20
"Boba Fett",100.00
`
	prog, err := parser.ParseProgram([]byte(src), nil)
	if err != nil {
		fmt.Println(err)
		return
	}
	config := &interp.Config{
		Stdin:     strings.NewReader(input),
		InputMode: interp.CSVMode,
		CSVInput:  interp.CSVInputConfig{Comment: '#', Header: true},
	}
	_, err = interp.ExecProgram(prog, config)
	if err != nil {
		fmt.Println(err)
		return
	}
	// Output:
	// 137.5
}