package pages

import (
	"fmt"
	"log/slog"
	"tasksquire/common"
	"tasksquire/taskwarrior"
	"time"

	"github.com/charmbracelet/bubbles/key"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/huh"
)

type TaskEditorPage struct {
	common *common.Common
	task   taskwarrior.Task
	form   *huh.Form
}

type TaskEditorKeys struct {
	Quit        key.Binding
	Up          key.Binding
	Down        key.Binding
	Select      key.Binding
	ToggleFocus key.Binding
}

func NewTaskEditorPage(common *common.Common, task taskwarrior.Task) *TaskEditorPage {
	p := &TaskEditorPage{
		common: common,
		task:   task,
	}

	if p.task.Priority == "" {
		p.task.Priority = "(none)"
	}
	if p.task.Project == "" {
		p.task.Project = "(none)"
	}

	priorityOptions := append([]string{"(none)"}, common.TW.GetPriorities()...)
	projectOptions := append([]string{"(none)"}, common.TW.GetProjects()...)
	tagOptions := common.TW.GetTags()

	p.form = huh.NewForm(
		huh.NewGroup(
			huh.NewInput().
				Title("Task").
				Value(&p.task.Description).
				Inline(true),

			huh.NewSelect[string]().
				Options(huh.NewOptions(priorityOptions...)...).
				Title("Priority").
				Value(&p.task.Priority),

			huh.NewSelect[string]().
				Options(huh.NewOptions(projectOptions...)...).
				Title("Project").
				Value(&p.task.Project),

			huh.NewMultiSelect[string]().
				Options(huh.NewOptions(tagOptions...)...).
				Title("Tags").
				Value(&p.task.Tags),

			huh.NewInput().
				Title("Due").
				Value(&p.task.Due).
				Validate(validateDate).
				Inline(true),

			huh.NewInput().
				Title("Scheduled").
				Value(&p.task.Scheduled).
				Validate(validateDate).
				Inline(true),

			huh.NewInput().
				Title("Wait").
				Value(&p.task.Wait).
				Validate(validateDate).
				Inline(true),
		),
	).
		WithShowHelp(false).
		WithShowErrors(false)

	return p
}

func (p *TaskEditorPage) Init() tea.Cmd {
	return p.form.Init()
}

func (p *TaskEditorPage) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch {
		case key.Matches(msg, p.common.Keymap.Back):
			model, err := p.common.PageStack.Pop()
			if err != nil {
				slog.Error("page stack empty")
				return nil, tea.Quit
			}
			return model, BackCmd
		}
	}

	f, cmd := p.form.Update(msg)
	if f, ok := f.(*huh.Form); ok {
		p.form = f
		cmds = append(cmds, cmd)
	}

	if p.form.State == huh.StateCompleted {
		cmds = append(cmds, p.addTaskCmd)
		model, err := p.common.PageStack.Pop()
		if err != nil {
			slog.Error("page stack empty")
			return nil, tea.Quit
		}
		return model, tea.Batch(cmds...)
	}

	return p, tea.Batch(cmds...)
}

func (p *TaskEditorPage) View() string {
	return p.common.Styles.Main.Render(p.form.View())
}

func (p *TaskEditorPage) addTaskCmd() tea.Msg {
	p.common.TW.AddTask(&p.task)
	return AddedTaskMsg{}
}

type AddedTaskMsg struct{}

// TODO: move this to taskwarrior; add missing date formats
func validateDate(s string) error {
	formats := []string{
		"2006-01-02",
		"2006-01-02T15:04",
		"20060102T150405Z",
	}

	otherFormats := []string{
		"",
		"now",
		"today",
		"sod",
		"eod",
		"yesterday",
		"tomorrow",
		"monday",
		"tuesday",
		"wednesday",
		"thursday",
		"friday",
		"saturday",
		"sunday",
		"mon",
		"tue",
		"wed",
		"thu",
		"fri",
		"sat",
		"sun",
		"soy",
		"eoy",
		"soq",
		"eoq",
		"som",
		"eom",
		"socm",
		"eocm",
		"sow",
		"eow",
		"socw",
		"eocw",
		"soww",
		"eoww",
		"1st",
		"2nd",
		"3rd",
		"4th",
		"5th",
		"6th",
		"7th",
		"8th",
		"9th",
		"10th",
		"11th",
		"12th",
		"13th",
		"14th",
		"15th",
		"16th",
		"17th",
		"18th",
		"19th",
		"20th",
		"21st",
		"22nd",
		"23rd",
		"24th",
		"25th",
		"26th",
		"27th",
		"28th",
		"29th",
		"30th",
		"31st",
	}

	for _, f := range formats {
		if _, err := time.Parse(f, s); err == nil {
			return nil
		}
	}

	for _, f := range otherFormats {
		if s == f {
			return nil
		}
	}

	return fmt.Errorf("invalid date")
}