package task

import (
	"fmt"
	"sort"
	"text/tabwriter"

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

// PrintTasksHelp prints tasks' help.
// Behavior is governed by listAll. When false, only tasks with descriptions are reported.
// When true, all tasks are reported with descriptions shown where available.
func (e *Executor) PrintTasksHelp(listAll bool) {
	var tasks []*taskfile.Task
	if listAll == true {
		tasks = e.allTaskNames()
	} else {
		tasks = e.tasksWithDesc()
	}

	if len(tasks) == 0 {
		// TODO: This message should be more informative. Maybe a hint to try -la for showing all?
		e.Logger.Outf(logger.Yellow, "task: No tasks with description available")
		return
	}
	e.Logger.Outf(logger.Default, "task: Available tasks for this project:")

	// Format in tab-separated columns with a tab stop of 8.
	w := tabwriter.NewWriter(e.Stdout, 0, 8, 0, '\t', 0)
	for _, task := range tasks {
		fmt.Fprintf(w, "* %s: \t%s\n", task.Name(), task.Desc)
	}
	w.Flush()
}

func (e *Executor) allTaskNames() (tasks []*taskfile.Task) {
	tasks = make([]*taskfile.Task, 0, len(e.Taskfile.Tasks))
	for _, task := range e.Taskfile.Tasks {
		tasks = append(tasks, task)
	}
	sort.Slice(tasks, func(i, j int) bool { return tasks[i].Task < tasks[j].Task })
	return
}

func (e *Executor) tasksWithDesc() (tasks []*taskfile.Task) {
	tasks = make([]*taskfile.Task, 0, len(e.Taskfile.Tasks))
	for _, task := range e.Taskfile.Tasks {
		if task.Desc != "" {
			compiledTask, err := e.FastCompiledTask(taskfile.Call{Task: task.Task})
			if err == nil {
				task = compiledTask
			}
			tasks = append(tasks, task)
		}
	}
	sort.Slice(tasks, func(i, j int) bool { return tasks[i].Task < tasks[j].Task })
	return
}

// ListTasksWithDesc reports tasks that have a description spec.
func (e *Executor) ListTasksWithDesc() {
	e.PrintTasksHelp(false)
	return
}

// ListAllTasks reports all tasks, with or without a description spec.
func (e *Executor) ListAllTasks() {
	e.PrintTasksHelp(true)
	return
}