package ui

import (
	"fmt"
	"strings"
	"time"

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

	"skyrama-tui/internal/model"
	"skyrama-tui/internal/service"
	"skyrama-tui/internal/style"
)

// ─── Messages ─────────────────────────────────────────────────────────────────

type ContractsLoadedMsg struct{ Contracts []model.Contract }
type ContractsErrMsg struct{ Err error }

// ─── ContractsModel ───────────────────────────────────────────────────────────

type ContractsModel struct {
	client    *service.GameService
	airportID uint32
	contracts []model.Contract
	cursor    int
	statusMsg string
	focused   bool
	width     int
	height    int
}

func NewContractsModel(client *service.GameService, airportID uint32) ContractsModel {
	return ContractsModel{client: client, airportID: airportID}
}

func (m ContractsModel) Init() tea.Cmd { return m.load() }

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

	case ContractsLoadedMsg:
		m.contracts = msg.Contracts
		if m.cursor >= len(m.contracts) {
			m.cursor = clampMin(len(m.contracts)-1, 0)
		}

	case ContractsErrMsg:
		m.statusMsg = style.Error.String() + msg.Err.Error()

	case tea.KeyMsg:
		if !m.focused {
			break
		}
		switch msg.String() {
		case "up", "k":
			if m.cursor > 0 {
				m.cursor--
			}
		case "down", "j":
			if m.cursor < len(m.contracts)-1 {
				m.cursor++
			}
		case "r":
			m.statusMsg = ""
			return m, m.load()
		}
	}
	return m, nil
}

func (m ContractsModel) View() string {
	header := style.PanelHeader.Render("📋  Active Contracts")

	statusLine := ""
	if m.statusMsg != "" {
		statusLine = "\n" + m.statusMsg + "\n"
	}

	if len(m.contracts) == 0 {
		return lipgloss.JoinVertical(lipgloss.Left,
			header,
			statusLine,
			"",
			style.Muted.Render("No active contracts right now."),
		)
	}

	rows := make([]string, len(m.contracts))
	for i, c := range m.contracts {
		rows[i] = m.renderContract(c, i == m.cursor)
	}

	help := style.HelpKey.Render("↑↓ / jk") + style.HelpDesc.Render(" navigate  ") +
		style.HelpKey.Render("r") + style.HelpDesc.Render(" refresh")

	return lipgloss.JoinVertical(lipgloss.Left,
		header,
		statusLine,
		strings.Join(rows, "\n"),
		"",
		style.Muted.Render(help),
	)
}

func (m ContractsModel) renderContract(c model.Contract, selected bool) string {
	pct := c.ProgressPct()
	barW := 24
	bar := style.ResourceBar(int(c.CurrentAmountDelivered), int(c.RequiredAmount), barW, style.ColorGreen)

	expiresIn := time.Until(c.ExpiresAt).Round(time.Minute)
	urgency := style.Muted
	if expiresIn < 30*time.Minute {
		urgency = style.Error
	} else if expiresIn < 2*time.Hour {
		urgency = style.Warning
	}

	inner := lipgloss.JoinVertical(lipgloss.Left,
		style.Bold.Render(c.Title),
		style.Muted.Render(fmt.Sprintf("Deliver %d × %s", c.RequiredAmount, c.ProductName)),
		lipgloss.JoinHorizontal(lipgloss.Top,
			bar,
			style.Muted.Render(fmt.Sprintf("  %d/%d (%d%%)",
				c.CurrentAmountDelivered, c.RequiredAmount, pct)),
		),
		urgency.Render(fmt.Sprintf("⏰ Expires in %s", fmtContractDuration(expiresIn))),
	)

	if selected {
		return style.PanelFocused.Render(inner)
	}
	return style.Panel.Render(inner)
}

// ─── Exported for parent AppModel ─────────────────────────────────────────────

// Load is the exported version for use by parent AppModel.
func (m ContractsModel) Load() tea.Cmd { return m.load() }

func (m ContractsModel) load() tea.Cmd {
	client := m.client
	airportID := m.airportID
	return func() tea.Msg {
		contracts, err := client.GetActiveContracts(airportID)
		if err != nil {
			return ContractsErrMsg{Err: err}
		}
		return ContractsLoadedMsg{Contracts: contracts}
	}
}

// ─── Helpers ──────────────────────────────────────────────────────────────────

func clampMin(v, min int) int {
	if v < min {
		return min
	}
	return v
}

func fmtContractDuration(d time.Duration) string {
	if d <= 0 {
		return "expired"
	}
	h := int(d.Hours())
	m := int(d.Minutes()) % 60
	if h > 0 {
		return fmt.Sprintf("%dh %dm", h, m)
	}
	return fmt.Sprintf("%dm", m)
}