package main

import (
	"fmt"
	"strings"
	"time"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

// CLI Model
type model struct {
	config     *Config
	stations   []StationData
	lastUpdate time.Time
	loading    bool
	width      int
	height     int
}

// Messages
type updateDataMsg []StationData
type tickMsg time.Time

func initialModel(config *Config) model {
	return model{
		config:  config,
		loading: true,
		width:   80,
		height:  24,
	}
}

func (m model) Init() tea.Cmd {
	return tea.Batch(
		fetchData(m.config.Stations),
		tickCmd(),
	)
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		return m, nil

	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c":
			return m, tea.Quit
		case "r":
			m.loading = true
			return m, fetchData(m.config.Stations)
		}

	case updateDataMsg:
		m.stations = []StationData(msg)
		m.lastUpdate = time.Now()
		m.loading = false
		return m, nil

	case tickMsg:
		return m, tea.Batch(
			fetchData(m.config.Stations),
			tickCmd(),
		)
	}

	return m, nil
}

func (m model) View() string {
	if m.loading && len(m.stations) == 0 {
		return lipgloss.NewStyle().
			Width(m.width).
			Align(lipgloss.Center).
			Render("Loading train data...")
	}

	var sections []string

	// Header
	headerStyle := lipgloss.NewStyle().
		Bold(true).
		Foreground(lipgloss.Color("15")).
		MarginBottom(1)

	timeStyle := lipgloss.NewStyle().
		Foreground(lipgloss.Color("8")).
		Align(lipgloss.Right)

	header := lipgloss.JoinHorizontal(
		lipgloss.Top,
		headerStyle.Width(m.width-20).Render("SUNDIAL"),
		timeStyle.Width(20).Render("Last updated: "+m.lastUpdate.Format("15:04")),
	)

	sections = append(sections, header)

	// Horizontal rule
	rule := strings.Repeat("─", m.width)
	sections = append(sections, rule)

	// Station tables
	for _, station := range m.stations {
		sections = append(sections, renderStation(station, m.width))
	}

	// Loading indicator
	if m.loading {
		sections = append(sections, "\nRefreshing...")
	}

	// Help
	help := lipgloss.NewStyle().
		Foreground(lipgloss.Color("8")).
		MarginTop(1).
		Render("Press 'r' to refresh, 'q' to quit")

	sections = append(sections, help)

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

// Commands
func fetchData(stations []Station) tea.Cmd {
	return func() tea.Msg {
		data := FetchAllStationsData(stations)
		return updateDataMsg(data)
	}
}

func tickCmd() tea.Cmd {
	return tea.Tick(60*time.Second, func(t time.Time) tea.Msg {
		return tickMsg(t)
	})
}

// Rendering functions
func renderStation(station StationData, width int) string {
	var sections []string

	// Station name
	stationStyle := lipgloss.NewStyle().
		Bold(true).
		Foreground(lipgloss.Color("15")).
		MarginTop(1).
		MarginBottom(1)

	sections = append(sections, stationStyle.Render(station.Station.Name+" ("+station.Station.Code+")"))

	if station.Error != "" {
		errorStyle := lipgloss.NewStyle().
			Foreground(lipgloss.Color("9")).
			Background(lipgloss.Color("1"))

		sections = append(sections, errorStyle.Render("ERROR: "+station.Error))
		return lipgloss.JoinVertical(lipgloss.Left, sections...)
	}

	if len(station.Departures) == 0 {
		sections = append(sections, "No departures found - The National Rail website now uses dynamic JavaScript to load departure data.")
		sections = append(sections, "This simple HTTP scraper cannot access the live data. Consider using the National Rail API instead.")
		return lipgloss.JoinVertical(lipgloss.Left, sections...)
	}

	// Table
	table := renderDeparturesTable(station.Departures, width-4)
	sections = append(sections, table)

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

func renderDeparturesTable(departures []Departure, width int) string {
	// Styles
	headerStyle := lipgloss.NewStyle().
		Bold(true).
		Foreground(lipgloss.Color("15"))

	cellStyle := lipgloss.NewStyle().
		Foreground(lipgloss.Color("15"))

	delayedStyle := lipgloss.NewStyle().
		Foreground(lipgloss.Color("9")) // Red

	// Column widths (matching web interface)
	timeWidth := 6                                     // "HH:MM"
	platformWidth := 4                                 // "Pl."
	destWidth := width - timeWidth - platformWidth - 4 // Remaining space minus padding

	// Header row
	headerRow := lipgloss.JoinHorizontal(
		lipgloss.Top,
		headerStyle.Width(timeWidth).Render("Time"),
		headerStyle.Width(destWidth).Render("Destination"),
		headerStyle.Width(platformWidth).Align(lipgloss.Right).Render("Pl."),
	)

	var rows []string
	rows = append(rows, headerRow)

	// Data rows
	for _, departure := range departures {
		// Time cell
		var timeText string
		if departure.ExpectedTime != "" {
			timeText = departure.ExpectedTime
		} else {
			timeText = departure.ScheduledTime
		}

		var timeCell string
		if departure.ExpectedTime != "" && departure.ExpectedTime != departure.ScheduledTime {
			timeCell = delayedStyle.Width(timeWidth).Render(timeText)
		} else {
			timeCell = cellStyle.Width(timeWidth).Render(timeText)
		}

		// Destination cell
		destText := departure.Destination
		if departure.Via != "" {
			destText += " " + departure.Via
		}
		destCell := cellStyle.Width(destWidth).Render(destText)

		// Platform cell
		platformCell := cellStyle.Width(platformWidth).Align(lipgloss.Right).Render(departure.Platform)

		row := lipgloss.JoinHorizontal(lipgloss.Top, timeCell, destCell, platformCell)
		rows = append(rows, row)
	}

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

// runTUI starts the Bubble Tea CLI application
func runTUI() error {
	config, err := LoadConfig("config.yaml")
	if err != nil {
		return fmt.Errorf("error loading config: %w", err)
	}

	p := tea.NewProgram(initialModel(config), tea.WithAltScreen())
	_, err = p.Run()
	return err
}