package feed

import (
	"time"

	"github.com/charmbracelet/bubbles/help"
	"github.com/charmbracelet/bubbles/key"
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
)

// Panel represents which panel has focus
type Panel int

const (
	PanelTree Panel = iota
	PanelFeed
)

// Event represents an activity event
type Event struct {
	Time     time.Time
	Type     string // create, update, complete, fail, delete
	Actor    string // who did it (e.g., "gastown/crew/joe")
	Target   string // what was affected (e.g., "gt-xyz")
	Message  string // human-readable description
	Rig      string // which rig
	Role     string // actor's role
	Raw      string // raw line for fallback display
}

// Agent represents an agent in the tree
type Agent struct {
	ID         string
	Name       string
	Role       string // mayor, witness, refinery, crew, polecat
	Rig        string
	Status     string // running, idle, working, dead
	LastEvent  *Event
	LastUpdate time.Time
	Expanded   bool
}

// Rig represents a rig with its agents
type Rig struct {
	Name     string
	Agents   map[string]*Agent // keyed by role/name
	Expanded bool
}

// Model is the main bubbletea model for the feed TUI
type Model struct {
	// Dimensions
	width  int
	height int

	// Panels
	focusedPanel Panel
	treeViewport viewport.Model
	feedViewport viewport.Model

	// Data
	rigs   map[string]*Rig
	events []Event

	// UI state
	keys         KeyMap
	help         help.Model
	showHelp     bool
	filter       string
	filterActive bool
	err          error

	// Event source
	eventChan <-chan Event
	done      chan struct{}
}

// NewModel creates a new feed TUI model
func NewModel() Model {
	h := help.New()
	h.ShowAll = false

	return Model{
		focusedPanel: PanelTree,
		treeViewport: viewport.New(0, 0),
		feedViewport: viewport.New(0, 0),
		rigs:         make(map[string]*Rig),
		events:       make([]Event, 0, 1000),
		keys:         DefaultKeyMap(),
		help:         h,
		done:         make(chan struct{}),
	}
}

// Init initializes the model
func (m Model) Init() tea.Cmd {
	return tea.Batch(
		m.listenForEvents(),
		tea.SetWindowTitle("GT Feed"),
	)
}

// eventMsg is sent when a new event arrives
type eventMsg Event

// tickMsg is sent periodically to refresh the view
type tickMsg time.Time

// listenForEvents returns a command that listens for events
func (m Model) listenForEvents() tea.Cmd {
	if m.eventChan == nil {
		return nil
	}
	return func() tea.Msg {
		select {
		case event, ok := <-m.eventChan:
			if !ok {
				return nil
			}
			return eventMsg(event)
		case <-m.done:
			return nil
		}
	}
}

// tick returns a command for periodic refresh
func tick() tea.Cmd {
	return tea.Tick(time.Second, func(t time.Time) tea.Msg {
		return tickMsg(t)
	})
}

// Update handles messages
func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		return m.handleKey(msg)

	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		m.updateViewportSizes()

	case eventMsg:
		m.addEvent(Event(msg))
		cmds = append(cmds, m.listenForEvents())

	case tickMsg:
		cmds = append(cmds, tick())
	}

	// Update viewports
	var cmd tea.Cmd
	if m.focusedPanel == PanelTree {
		m.treeViewport, cmd = m.treeViewport.Update(msg)
	} else {
		m.feedViewport, cmd = m.feedViewport.Update(msg)
	}
	cmds = append(cmds, cmd)

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

// handleKey processes key presses
func (m Model) handleKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
	switch {
	case key.Matches(msg, m.keys.Quit):
		close(m.done)
		return m, tea.Quit

	case key.Matches(msg, m.keys.Help):
		m.showHelp = !m.showHelp
		m.help.ShowAll = m.showHelp
		return m, nil

	case key.Matches(msg, m.keys.Tab):
		if m.focusedPanel == PanelTree {
			m.focusedPanel = PanelFeed
		} else {
			m.focusedPanel = PanelTree
		}
		return m, nil

	case key.Matches(msg, m.keys.FocusTree):
		m.focusedPanel = PanelTree
		return m, nil

	case key.Matches(msg, m.keys.FocusFeed):
		m.focusedPanel = PanelFeed
		return m, nil

	case key.Matches(msg, m.keys.Refresh):
		m.updateViewContent()
		return m, nil
	}

	// Pass to focused viewport
	var cmd tea.Cmd
	if m.focusedPanel == PanelTree {
		m.treeViewport, cmd = m.treeViewport.Update(msg)
	} else {
		m.feedViewport, cmd = m.feedViewport.Update(msg)
	}
	return m, cmd
}

// updateViewportSizes recalculates viewport dimensions
func (m *Model) updateViewportSizes() {
	// Reserve space: header (1) + borders (4) + status bar (1) + help (1-2)
	headerHeight := 1
	statusHeight := 1
	helpHeight := 1
	if m.showHelp {
		helpHeight = 3
	}
	borderHeight := 4 // top and bottom borders for both panels

	availableHeight := m.height - headerHeight - statusHeight - helpHeight - borderHeight
	if availableHeight < 4 {
		availableHeight = 4
	}

	// Split 40% tree, 60% feed
	treeHeight := availableHeight * 40 / 100
	feedHeight := availableHeight - treeHeight

	contentWidth := m.width - 4 // borders and padding
	if contentWidth < 20 {
		contentWidth = 20
	}

	m.treeViewport.Width = contentWidth
	m.treeViewport.Height = treeHeight
	m.feedViewport.Width = contentWidth
	m.feedViewport.Height = feedHeight

	m.updateViewContent()
}

// updateViewContent refreshes the content of both viewports
func (m *Model) updateViewContent() {
	m.treeViewport.SetContent(m.renderTree())
	m.feedViewport.SetContent(m.renderFeed())
}

// addEvent adds an event and updates the agent tree
func (m *Model) addEvent(e Event) {
	m.events = append(m.events, e)

	// Keep max 1000 events
	if len(m.events) > 1000 {
		m.events = m.events[len(m.events)-1000:]
	}

	// Update agent tree
	if e.Rig != "" {
		rig, ok := m.rigs[e.Rig]
		if !ok {
			rig = &Rig{
				Name:     e.Rig,
				Agents:   make(map[string]*Agent),
				Expanded: true,
			}
			m.rigs[e.Rig] = rig
		}

		if e.Actor != "" {
			agent, ok := rig.Agents[e.Actor]
			if !ok {
				agent = &Agent{
					ID:   e.Actor,
					Name: e.Actor,
					Role: e.Role,
					Rig:  e.Rig,
				}
				rig.Agents[e.Actor] = agent
			}
			agent.LastEvent = &e
			agent.LastUpdate = e.Time
		}
	}

	m.updateViewContent()
}

// SetEventChannel sets the channel to receive events from
func (m *Model) SetEventChannel(ch <-chan Event) {
	m.eventChan = ch
}

// View renders the TUI
func (m Model) View() string {
	return m.render()
}