package pages

import (
	"log/slog"
	"strings"
	"tasksquire/common"
	"tasksquire/components/autocomplete"
	"tasksquire/components/picker"
	"tasksquire/components/timestampeditor"
	"tasksquire/timewarrior"

	"github.com/charmbracelet/bubbles/key"
	"github.com/charmbracelet/bubbles/list"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

type TimeEditorPage struct {
	common   *common.Common
	interval *timewarrior.Interval

	// Fields
	projectPicker *picker.Picker
	startEditor   *timestampeditor.TimestampEditor
	endEditor     *timestampeditor.TimestampEditor
	tagsInput     *autocomplete.Autocomplete
	adjust        bool

	// State
	selectedProject string
	currentField    int
	totalFields     int
}

type timeEditorProjectSelectedMsg struct {
	project string
}

func NewTimeEditorPage(com *common.Common, interval *timewarrior.Interval) *TimeEditorPage {
	// Extract project from tags if it exists
	projects := com.TW.GetProjects()
	selectedProject, remainingTags := extractProjectFromTags(interval.Tags, projects)

	// Create project picker with onCreate support for new projects
	projectItemProvider := func() []list.Item {
		projects := com.TW.GetProjects()
		items := make([]list.Item, len(projects))
		for i, proj := range projects {
			items[i] = picker.NewItem(proj)
		}
		return items
	}

	projectOnSelect := func(item list.Item) tea.Cmd {
		return func() tea.Msg {
			return timeEditorProjectSelectedMsg{project: item.FilterValue()}
		}
	}

	projectOnCreate := func(name string) tea.Cmd {
		return func() tea.Msg {
			return timeEditorProjectSelectedMsg{project: name}
		}
	}

	opts := []picker.PickerOption{
		picker.WithOnCreate(projectOnCreate),
	}
	if selectedProject != "" {
		opts = append(opts, picker.WithDefaultValue(selectedProject))
	} else {
		opts = append(opts, picker.WithFilterByDefault(true))
	}

	projectPicker := picker.New(
		com,
		"Project",
		projectItemProvider,
		projectOnSelect,
		opts...,
	)
	projectPicker.SetSize(50, 10) // Compact size for inline use

	// Create start timestamp editor
	startEditor := timestampeditor.New(com).
		Title("Start").
		ValueFromString(interval.Start)

	// Create end timestamp editor
	endEditor := timestampeditor.New(com).
		Title("End").
		ValueFromString(interval.End)

	// Get tag combinations filtered by selected project
	tagCombinations := filterTagCombinationsByProject(
		com.TimeW.GetTagCombinations(),
		selectedProject,
	)

	tagsInput := autocomplete.New(tagCombinations, 3, 10)
	tagsInput.SetPlaceholder("Space separated, use \"\" for tags with spaces")
	tagsInput.SetValue(formatTags(remainingTags)) // Use remaining tags (without project)
	tagsInput.SetWidth(50)

	p := &TimeEditorPage{
		common:          com,
		interval:        interval,
		projectPicker:   projectPicker,
		startEditor:     startEditor,
		endEditor:       endEditor,
		tagsInput:       tagsInput,
		adjust:          true, // Enable :adjust by default
		selectedProject: selectedProject,
		currentField:    0,
		totalFields:     5, // Now 5 fields: project, tags, start, end, adjust
	}

	return p
}

func (p *TimeEditorPage) Init() tea.Cmd {
	// Focus the first field (project picker)
	p.currentField = 0
	return p.projectPicker.Init()
}

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

	switch msg := msg.(type) {
	case timeEditorProjectSelectedMsg:
		// Update selected project
		p.selectedProject = msg.project
		// Blur current field (project picker)
		p.blurCurrentField()
		// Advance to tags field
		p.currentField = 1
		// Refresh tag autocomplete with filtered combinations
		cmds = append(cmds, p.updateTagSuggestions())
		// Focus tags input
		cmds = append(cmds, p.focusCurrentField())
		return p, tea.Batch(cmds...)

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

		case key.Matches(msg, p.common.Keymap.Ok):
			// Handle Enter based on current field
			if p.currentField == 0 {
				// Project picker - let it handle Enter (will trigger projectSelectedMsg)
				break
			}

			if p.currentField == 1 {
				// Tags field
				if p.tagsInput.HasSuggestions() {
					// Let autocomplete handle suggestion selection
					break
				}
				// Tags confirmed without suggestions - advance to start timestamp
				p.blurCurrentField()
				p.currentField = 2
				cmds = append(cmds, p.focusCurrentField())
				return p, tea.Batch(cmds...)
			}

			// For all other fields (2-4: start, end, adjust), save and exit
			p.saveInterval()
			model, err := p.common.PopPage()
			if err != nil {
				slog.Error("page stack empty")
				return nil, tea.Quit
			}
			return model, tea.Batch(tea.Batch(cmds...), refreshIntervals)

		case key.Matches(msg, p.common.Keymap.Next):
			// Move to next field
			p.blurCurrentField()
			p.currentField = (p.currentField + 1) % p.totalFields
			cmds = append(cmds, p.focusCurrentField())

		case key.Matches(msg, p.common.Keymap.Prev):
			// Move to previous field
			p.blurCurrentField()
			p.currentField = (p.currentField - 1 + p.totalFields) % p.totalFields
			cmds = append(cmds, p.focusCurrentField())
		}

	case tea.WindowSizeMsg:
		p.SetSize(msg.Width, msg.Height)
	}

	// Update the currently focused field
	var cmd tea.Cmd
	switch p.currentField {
	case 0: // Project picker
		var model tea.Model
		model, cmd = p.projectPicker.Update(msg)
		if pk, ok := model.(*picker.Picker); ok {
			p.projectPicker = pk
		}
	case 1: // Tags (was 0)
		var model tea.Model
		model, cmd = p.tagsInput.Update(msg)
		if ac, ok := model.(*autocomplete.Autocomplete); ok {
			p.tagsInput = ac
		}
	case 2: // Start (was 1)
		var model tea.Model
		model, cmd = p.startEditor.Update(msg)
		if editor, ok := model.(*timestampeditor.TimestampEditor); ok {
			p.startEditor = editor
		}
	case 3: // End (was 2)
		var model tea.Model
		model, cmd = p.endEditor.Update(msg)
		if editor, ok := model.(*timestampeditor.TimestampEditor); ok {
			p.endEditor = editor
		}
	case 4: // Adjust (was 3)
		// Handle adjust toggle with space/enter
		if msg, ok := msg.(tea.KeyMsg); ok {
			if msg.String() == " " || msg.String() == "enter" {
				p.adjust = !p.adjust
			}
		}
	}
	cmds = append(cmds, cmd)

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

func (p *TimeEditorPage) focusCurrentField() tea.Cmd {
	switch p.currentField {
	case 0:
		return p.projectPicker.Init() // Picker doesn't have explicit Focus()
	case 1:
		p.tagsInput.Focus()
		return p.tagsInput.Init()
	case 2:
		return p.startEditor.Focus()
	case 3:
		return p.endEditor.Focus()
	case 4:
		// Adjust checkbox doesn't need focus action
		return nil
	}
	return nil
}

func (p *TimeEditorPage) blurCurrentField() {
	switch p.currentField {
	case 0:
		// Picker doesn't have explicit Blur(), state handled by Update
	case 1:
		p.tagsInput.Blur()
	case 2:
		p.startEditor.Blur()
	case 3:
		p.endEditor.Blur()
	case 4:
		// Adjust checkbox doesn't need blur action
	}
}

func (p *TimeEditorPage) View() string {
	var sections []string

	// Title
	titleStyle := p.common.Styles.Form.Focused.Title
	sections = append(sections, titleStyle.Render("Edit Time Interval"))
	sections = append(sections, "")

	// Project picker (field 0)
	if p.currentField == 0 {
		sections = append(sections, p.projectPicker.View())
	} else {
		blurredLabelStyle := p.common.Styles.Form.Blurred.Title
		sections = append(sections, blurredLabelStyle.Render("Project"))
		sections = append(sections, lipgloss.NewStyle().Faint(true).Render(p.selectedProject))
	}

	sections = append(sections, "")
	sections = append(sections, "")

	// Tags input (now field 1, was first)
	tagsLabelStyle := p.common.Styles.Form.Focused.Title
	tagsLabel := tagsLabelStyle.Render("Tags")
	if p.currentField == 1 { // Changed from 0
		sections = append(sections, tagsLabel)
		sections = append(sections, p.tagsInput.View())
		descStyle := p.common.Styles.Form.Focused.Description
		sections = append(sections, descStyle.Render("Space separated, use \"\" for tags with spaces"))
	} else {
		blurredLabelStyle := p.common.Styles.Form.Blurred.Title
		sections = append(sections, blurredLabelStyle.Render("Tags"))
		sections = append(sections, lipgloss.NewStyle().Faint(true).Render(p.tagsInput.GetValue()))
	}

	sections = append(sections, "")
	sections = append(sections, "")

	// Start editor
	sections = append(sections, p.startEditor.View())
	sections = append(sections, "")

	// End editor
	sections = append(sections, p.endEditor.View())
	sections = append(sections, "")

	// Adjust checkbox (now field 4, was 3)
	adjustLabelStyle := p.common.Styles.Form.Focused.Title
	adjustLabel := adjustLabelStyle.Render("Adjust overlaps")

	var checkbox string
	if p.adjust {
		checkbox = "[X]"
	} else {
		checkbox = "[ ]"
	}

	if p.currentField == 4 { // Changed from 3
		focusedStyle := lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("12"))
		sections = append(sections, adjustLabel)
		sections = append(sections, focusedStyle.Render(checkbox+" Auto-adjust overlapping intervals"))
		descStyle := p.common.Styles.Form.Focused.Description
		sections = append(sections, descStyle.Render("Press space to toggle"))
	} else {
		blurredLabelStyle := p.common.Styles.Form.Blurred.Title
		sections = append(sections, blurredLabelStyle.Render("Adjust overlaps"))
		sections = append(sections, lipgloss.NewStyle().Faint(true).Render(checkbox+" Auto-adjust overlapping intervals"))
	}

	sections = append(sections, "")
	sections = append(sections, "")

	// Help text
	helpStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("8"))
	sections = append(sections, helpStyle.Render("tab/shift+tab: navigate • enter: save • esc: cancel"))

	return lipgloss.JoinVertical(lipgloss.Left, sections...)
}

func (p *TimeEditorPage) SetSize(width, height int) {
	p.common.SetSize(width, height)
}

func (p *TimeEditorPage) saveInterval() {
	// If it's an existing interval (has ID), delete it first so we can replace it with the modified version
	if p.interval.ID != 0 {
		err := p.common.TimeW.DeleteInterval(p.interval.ID)
		if err != nil {
			slog.Error("Failed to delete old interval during edit", "err", err)
			// Proceeding to import anyway, attempting to save user data
		}
	}

	p.interval.Start = p.startEditor.GetValueString()
	p.interval.End = p.endEditor.GetValueString()

	// Parse tags from input
	tags := parseTags(p.tagsInput.GetValue())

	// Add project to tags if not already present
	if p.selectedProject != "" {
		projectTag := "project:" + p.selectedProject
		projectExists := false
		for _, tag := range tags {
			if tag == projectTag {
				projectExists = true
				break
			}
		}
		if !projectExists {
			tags = append([]string{projectTag}, tags...) // Prepend project tag
		}
	}

	p.interval.Tags = tags

	err := p.common.TimeW.ModifyInterval(p.interval, p.adjust)
	if err != nil {
		slog.Error("Failed to modify interval", "err", err)
	}
}

func parseTags(tagsStr string) []string {
	var tags []string
	var current strings.Builder
	inQuotes := false

	for _, r := range tagsStr {
		switch {
		case r == '"':
			inQuotes = !inQuotes
		case r == ' ' && !inQuotes:
			if current.Len() > 0 {
				tags = append(tags, current.String())
				current.Reset()
			}
		default:
			current.WriteRune(r)
		}
	}
	if current.Len() > 0 {
		tags = append(tags, current.String())
	}
	return tags
}

func formatTags(tags []string) string {
	var formatted []string
	for _, t := range tags {
		if strings.Contains(t, " ") {
			formatted = append(formatted, "\""+t+"\"")
		} else {
			formatted = append(formatted, t)
		}
	}
	return strings.Join(formatted, " ")
}

// extractProjectFromTags finds and removes the first tag that matches a known project
// Returns the found project (or empty string) and the remaining tags
func extractProjectFromTags(tags []string, projects []string) (string, []string) {
	projectSet := make(map[string]bool)
	for _, p := range projects {
		projectSet[p] = true
	}

	var foundProject string
	var remaining []string

	for _, tag := range tags {
		// Check if this tag is a project tag (format: "project:projectname")
		if strings.HasPrefix(tag, "project:") {
			projectName := strings.TrimPrefix(tag, "project:")
			if foundProject == "" && projectSet[projectName] {
				foundProject = projectName // First matching project
				continue                   // Don't add to remaining tags
			}
		}
		remaining = append(remaining, tag)
	}

	return foundProject, remaining
}

// filterTagCombinationsByProject filters tag combinations to only show those
// containing the exact project tag, and removes the project from the displayed combination
func filterTagCombinationsByProject(combinations []string, project string) []string {
	if project == "" {
		return combinations
	}

	projectTag := "project:" + project

	var filtered []string
	for _, combo := range combinations {
		// Parse the combination into individual tags
		tags := parseTags(combo)

		// Check if project exists in this combination
		for _, tag := range tags {
			if tag == projectTag {
				// Found the project - now remove it from display
				var displayTags []string
				for _, t := range tags {
					if t != projectTag {
						displayTags = append(displayTags, t)
					}
				}
				if len(displayTags) > 0 {
					filtered = append(filtered, formatTags(displayTags))
				}
				break
			}
		}
	}

	return filtered
}

// updateTagSuggestions refreshes the tag autocomplete with filtered combinations
func (p *TimeEditorPage) updateTagSuggestions() tea.Cmd {
	combinations := filterTagCombinationsByProject(
		p.common.TimeW.GetTagCombinations(),
		p.selectedProject,
	)

	// Update autocomplete suggestions
	currentValue := p.tagsInput.GetValue()
	p.tagsInput.SetSuggestions(combinations)
	p.tagsInput.SetValue(currentValue)

	// If tags field is focused, refocus it
	if p.currentField == 1 {
		p.tagsInput.Focus()
		return p.tagsInput.Init()
	}

	return nil
}