package dashboard

import (
	"fmt"
	"strings"
	"time"

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

	"github.com/MDietermann/ArduinoArchSetup/internal/engine"
	"github.com/MDietermann/ArduinoArchSetup/internal/tui"
)

// DoneMsg is sent from the engine goroutine once engine.Run returns.
type DoneMsg struct {
	Summary engine.Summary
	Err     error
}

// rowState tracks per-module progress in the dashboard.
// Name, Started, and Ended are populated for future use by elapsed-time
// rendering (planned for a later iteration); they are currently not read by View.
type rowState struct {
	ID         string
	Name       string
	Current    int
	Total      int
	LastMsg    string
	LogTail    []string
	StatusIcon string // ·, ⠋ (running), ✓, ✗, ⊘
	Done       bool
	Started    time.Time
	Ended      time.Time
	Err        error
}

// Model is the Bubble Tea model for the Apply-phase dashboard.
type Model struct {
	rows     []*rowState
	rowIndex map[string]*rowState
	cursor   int
	showLogs bool
	summary  *engine.Summary
	runErr   error
}

// NewModel seeds the dashboard from the list of module IDs selected to run.
// Rows start in the "pending" state and flip to running on first ProgressMsg.
func NewModel(selected []string, nameByID map[string]string) *Model {
	m := &Model{rowIndex: make(map[string]*rowState, len(selected))}
	for _, id := range selected {
		name := id
		if n, ok := nameByID[id]; ok {
			name = n
		}
		r := &rowState{ID: id, Name: name, StatusIcon: "·"}
		m.rows = append(m.rows, r)
		m.rowIndex[id] = r
	}
	return m
}

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

func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tui.ProgressMsg:
		// Guard: ignore late Progress events that arrive after DoneMsg has
		// finalised this row. tea.Program.Send is asynchronous and concurrent
		// goroutines have no arrival-order guarantee.
		if r, ok := m.rowIndex[msg.ModuleID]; ok && !r.Done {
			if r.Started.IsZero() {
				r.Started = time.Now()
			}
			r.Current = msg.Current
			r.Total = msg.Total
			r.LastMsg = msg.Message
			r.StatusIcon = "⠋"
		}
	case tui.LogMsg:
		if r, ok := m.rowIndex[msg.ModuleID]; ok && !r.Done {
			r.LogTail = appendCapped(r.LogTail, msg.Line, 200)
		}
	case DoneMsg:
		m.summary = &msg.Summary
		m.runErr = msg.Err
		for _, res := range msg.Summary.Results {
			r, ok := m.rowIndex[res.ID]
			if !ok {
				continue
			}
			r.Done = true
			r.Ended = time.Now()
			switch res.Status {
			case engine.StatusSucceeded, engine.StatusPlanned:
				r.StatusIcon = "✓"
			case engine.StatusFailed:
				r.StatusIcon = "✗"
				r.Err = res.Err
			case engine.StatusSkipped:
				r.StatusIcon = "⊘"
			}
		}
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c":
			return m, tea.Quit
		case "up", "k":
			if m.cursor > 0 {
				m.cursor--
			}
		case "down", "j":
			if m.cursor < len(m.rows)-1 {
				m.cursor++
			}
		case "enter":
			m.showLogs = !m.showLogs
		}
	}
	return m, nil
}

func (m *Model) View() string {
	var b strings.Builder
	header := lipgloss.NewStyle().Bold(true).Render("archduino install")
	b.WriteString(header + "\n")

	for i, r := range m.rows {
		cursor := "  "
		if i == m.cursor {
			cursor = "▸ "
		}
		progress := ""
		if r.Total > 0 {
			progress = fmt.Sprintf("%d/%d", r.Current, r.Total)
		}
		detail := r.LastMsg
		if r.Err != nil {
			detail = "failed — " + r.Err.Error()
		}
		fmt.Fprintf(&b, "%s%s %-16s %-6s %s\n", cursor, r.StatusIcon, r.ID, progress, detail)
	}

	if m.showLogs && len(m.rows) > 0 {
		active := m.rows[m.cursor]
		b.WriteString("\n─ log tail ─\n")
		for _, line := range active.LogTail {
			b.WriteString("  " + line + "\n")
		}
	}

	if m.summary != nil {
		ok, fail, skip := m.summary.Counts()
		fmt.Fprintf(&b, "\nsummary: %d succeeded, %d failed, %d skipped\n", ok, fail, skip)
		if m.runErr != nil {
			fmt.Fprintf(&b, "error: %v\n", m.runErr)
		}
		b.WriteString("\n[q] quit\n")
	} else {
		b.WriteString("\n[↑/↓] navigate  [enter] toggle log  [q] abort\n")
	}
	return b.String()
}

// Summary returns the engine summary once the run has completed, or nil.
func (m *Model) Summary() *engine.Summary { return m.summary }

// RunErr returns the engine's top-level error, if any.
func (m *Model) RunErr() error { return m.runErr }

func appendCapped(s []string, line string, max int) []string {
	s = append(s, line)
	if len(s) > max {
		s = s[len(s)-max:]
	}
	return s
}