package taskfile

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/go-task/task/v3/errors"
	"github.com/go-task/task/v3/internal/experiments"
	"github.com/go-task/task/v3/internal/logger"
)

type Node interface {
	Read(ctx context.Context) ([]byte, error)
	Parent() Node
	Location() string
	Dir() string
	Remote() bool
	ResolveEntrypoint(entrypoint string) (string, error)
	ResolveDir(dir string) (string, error)
}

func NewRootNode(
	l *logger.Logger,
	entrypoint string,
	dir string,
	insecure bool,
	timeout time.Duration,
) (Node, error) {
	dir = getDefaultDir(entrypoint, dir)
	// Check if there is something to read on STDIN
	stat, _ := os.Stdin.Stat()
	if (stat.Mode()&os.ModeCharDevice) == 0 && stat.Size() > 0 {
		return NewStdinNode(dir)
	}
	return NewNode(l, entrypoint, dir, insecure, timeout)
}

func NewNode(
	l *logger.Logger,
	entrypoint string,
	dir string,
	insecure bool,
	timeout time.Duration,
	opts ...NodeOption,
) (Node, error) {
	var node Node
	var err error
	switch getScheme(entrypoint) {
	case "http", "https":
		node, err = NewHTTPNode(l, entrypoint, dir, insecure, timeout, opts...)
	default:
		// If no other scheme matches, we assume it's a file
		node, err = NewFileNode(l, entrypoint, dir, opts...)
	}
	if node.Remote() && !experiments.RemoteTaskfiles.Enabled {
		return nil, errors.New("task: Remote taskfiles are not enabled. You can read more about this experiment and how to enable it at https://taskfile.dev/experiments/remote-taskfiles")
	}
	return node, err
}

func getScheme(uri string) string {
	if i := strings.Index(uri, "://"); i != -1 {
		return uri[:i]
	}
	return ""
}

func getDefaultDir(entrypoint, dir string) string {
	// If the entrypoint and dir are empty, we default the directory to the current working directory
	if dir == "" {
		if entrypoint == "" {
			wd, err := os.Getwd()
			if err != nil {
				return ""
			}
			dir = wd
		}
		return dir
	}

	// If the directory is set, ensure it is an absolute path
	var err error
	dir, err = filepath.Abs(dir)
	if err != nil {
		return ""
	}

	return dir
}