// Package ui implements the bubbletea TUI — the "Focused Forge" interface
// used by admins who want deep y/n configuration without leaving the
// terminal.
//
// Layout (tmux-style):
//
//   ┌─────────────────────────────────────────┐
//   │ 🔮 SORCERY-Go · Casting: wget, openssl   │  header
//   ├─────────────────────────────────────────┤
//   │ [scrollable build log]                   │  viewport
//   │ ...                                      │
//   ├─────────────────────────────────────────┤
//   │ [LOAD 2.41] [JOBS 3/12]  ▓▓▓▓▓░░░ 42%    │  status bar
//   └─────────────────────────────────────────┘
package ui

import (
        "fmt"
        "strings"

        "github.com/charmbracelet/bubbles/progress"
        "github.com/charmbracelet/bubbles/viewport"
        tea "github.com/charmbracelet/bubbletea"
        "github.com/charmbracelet/lipgloss"
)

// Model holds the entire TUI state.
type Model struct {
        casting   []string
        completed int
        total     int
        logs      viewport.Model
        progress  progress.Model
        width     int
        height    int
        logLines  []string
}

var (
        statusStyle = lipgloss.NewStyle().
                        Foreground(lipgloss.Color("#FFFFFF")).
                        Background(lipgloss.Color("#353535")).
                        Bold(true)
        logStyle = lipgloss.NewStyle().
                        Border(lipgloss.NormalBorder(), true, false, false, false).
                        BorderForeground(lipgloss.Color("#555555"))
)

// NewModel returns the initial TUI state.
func NewModel(total int) Model {
        vp := viewport.New(80, 20)
        p := progress.New(progress.WithDefaultGradient())
        return Model{
                total:    total,
                logs:     vp,
                progress: p,
                casting:  []string{},
        }
}

// Init satisfies tea.Model.
func (m Model) Init() tea.Cmd { return nil }

// Update handles messages from the engine.
func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
        switch msg := msg.(type) {
        case tea.KeyMsg:
                if msg.String() == "q" || msg.String() == "ctrl+c" {
                        return m, tea.Quit
                }
        case LogMsg:
                m.logLines = append(m.logLines, string(msg))
                m.logs.SetContent(strings.Join(m.logLines, "\n"))
        case CastCompleteMsg:
                m.completed++
                pct := float64(m.completed) / float64(m.total)
                return m, m.progress.SetPercent(pct)
        case tea.WindowSizeMsg:
                m.width, m.height = msg.Width, msg.Height
                m.logs.Width = msg.Width
                m.logs.Height = msg.Height - 4
        }
        var cmd tea.Cmd
        m.logs, cmd = m.logs.Update(msg)
        return m, cmd
}

// View renders the screen.
func (m Model) View() string {
        header := fmt.Sprintf(" 🔮 SORCERY-Go · Casting: %s", strings.Join(m.casting, ", "))
        statusText := fmt.Sprintf(" [JOBS: %d/%d] [ROOT: /]", m.completed, m.total)
        spacer := strings.Repeat(" ", max(0, m.width-len(statusText)-20))
        bar := lipgloss.JoinHorizontal(lipgloss.Top,
                statusStyle.Render(statusText),
                spacer,
                m.progress.View(),
        )
        return lipgloss.JoinVertical(lipgloss.Left,
                header,
                logStyle.Width(m.width).Height(m.height-4).Render(m.logs.View()),
                bar,
        )
}

// LogMsg is one line of build output streamed into the viewport.
type LogMsg string

// CastCompleteMsg is fired when a worker finishes a spell.
type CastCompleteMsg struct{ Name string }