package tui

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/bubbles/viewport"
	"github.com/charmbracelet/lipgloss"

	"proxyctl/internal/app"
)

type dashboardRenderState struct {
	catalog           targetCatalog
	selectedTargetID  string
	focus             dashboardPane
	detailsOffset     int
	operationProgress map[string]app.TargetProgressPhase
	applyingFrame     string
	terminalWidth     int
	terminalHeight    int
}

func (p terminalPresentation) renderDashboard(state dashboardRenderState, width, height int) string {
	if state.terminalWidth >= wideWidth && state.terminalHeight >= wideHeight {
		leftWidth := (width - 1) * 2 / 5
		rightWidth := width - leftWidth - 1
		left := p.renderTargetListPane(state, leftWidth, height)
		right := p.renderTargetDetailsPane(state, rightWidth, height)
		divider := strings.Repeat("│\n", max(0, height-1)) + "│"
		return lipgloss.JoinHorizontal(lipgloss.Top, left, divider, right)
	}

	listHeight := max(5, height/2)
	detailsHeight := height - listHeight - 1
	if detailsHeight < 4 {
		detailsHeight = 4
		listHeight = max(3, height-detailsHeight-1)
	}
	return p.renderTargetListPane(state, width, listHeight) + "\n" +
		p.renderTargetDetailsPane(state, width, detailsHeight)
}

func (p terminalPresentation) renderTargetListPane(state dashboardRenderState, width, height int) string {
	heading := paneHeading("Targets", state.focus == targetListPane)
	bodyHeight := max(1, height-2)
	lines := make([]string, 0, len(state.catalog.items))
	selectedIndex := state.catalog.index(state.selectedTargetID)
	for _, item := range state.catalog.items {
		cursor := "  "
		if item.ID == state.selectedTargetID {
			cursor = "> "
		}
		badge := p.targetBadge(item, state.operationProgress[item.ID], state.applyingFrame)
		lines = append(lines, cursor+badge+"  "+item.Description.Name)
	}
	if len(lines) == 0 {
		lines = append(lines, "No Targets are currently Available.")
		selectedIndex = 0
	}
	offset := 0
	if selectedIndex >= bodyHeight {
		offset = selectedIndex - bodyHeight + 1
	}
	body := fixedViewport(protectRenderedText(strings.Join(lines, "\n")), width, bodyHeight, offset, false)
	return fitPane(heading+"\n"+paneRule(width)+"\n"+body, width, height)
}

func (p terminalPresentation) renderTargetDetailsPane(state dashboardRenderState, width, height int) string {
	heading := paneHeading("Target details", state.focus == targetDetailsPane)
	bodyHeight := max(1, height-2)
	selected, ok := state.catalog.selected(state.selectedTargetID)
	content := "Select a Target to review its details."
	if ok {
		content = p.targetDetails(selected, state.operationProgress[selected.ID], state.applyingFrame)
	}
	body := fixedViewport(content, width, bodyHeight, state.detailsOffset, true)
	return fitPane(heading+"\n"+paneRule(width)+"\n"+body, width, height)
}

func paneHeading(label string, focused bool) string {
	if focused {
		return "▶ " + label + " [focused]"
	}
	return "  " + label
}

func paneRule(width int) string {
	return strings.Repeat("─", max(1, width))
}

func fitPane(content string, width, height int) string {
	return lipgloss.NewStyle().Width(width).Height(height).MaxWidth(width).MaxHeight(height).Render(content)
}

func fixedViewport(content string, width, height, offset int, wrap bool) string {
	if wrap {
		content = lipgloss.NewStyle().Width(width).Render(content)
	}
	view := viewport.New(width, height)
	view.SetContent(strings.TrimRight(content, "\n"))
	view.SetYOffset(max(0, offset))
	return view.View()
}

func (p terminalPresentation) targetBadge(item app.TargetSnapshot, progress app.TargetProgressPhase, applyingFrame string) string {
	switch item.DetectionPhase {
	case app.TargetChecking:
		return p.theme.checking.Render("… Checking")
	case app.TargetDetectionFailed:
		return p.theme.checkFailed.Render("! Failed")
	}
	if !item.Available {
		return p.theme.unavailable.Render("○ Unavailable")
	}
	actual := p.theme.renderTargetState(item.State, false)
	switch progress {
	case app.TargetProgressRunning:
		if applyingFrame == "" {
			applyingFrame = "|"
		}
		return p.theme.applying.Render(applyingFrame + " Applying")
	case app.TargetProgressFailed:
		return actual + "  " + p.theme.checkFailed.Render("! Failed")
	default:
		return actual
	}
}

func (p terminalPresentation) targetDetails(item app.TargetSnapshot, progress app.TargetProgressPhase, applyingFrame string) string {
	state := p.targetBadge(item, progress, applyingFrame)
	evidence := item.Evidence
	switch item.DetectionPhase {
	case app.TargetChecking:
		evidence = "Availability and configuration inspection are in progress."
	case app.TargetDetectionFailed:
		if evidence == "" {
			evidence = item.AvailabilityEvidence
		}
	default:
		if !item.Available {
			evidence = item.AvailabilityEvidence
		}
	}
	if evidence == "" {
		evidence = "No detection evidence reported."
	}

	var details strings.Builder
	details.WriteString(p.theme.section.Render(item.Description.Name))
	fmt.Fprintf(&details, "\n%s\n%s", state, evidence)
	action := targetActionLabel(item.PrimaryAction.Kind)
	if item.PrimaryAction.Available {
		fmt.Fprintf(&details, "\n\nSpace: %s", action)
	} else if item.PrimaryAction.DisabledReason != "" {
		fmt.Fprintf(&details, "\n\nUnavailable: %s", item.PrimaryAction.DisabledReason)
	}
	if item.DetectionPhase == app.TargetDetectionFailed && item.DetectionErr != nil {
		fmt.Fprintf(&details, "\nCheck failed: %s", item.DetectionErr)
	}
	if item.Description.Summary != "" {
		fmt.Fprintf(&details, "\n\n%s", item.Description.Summary)
	}
	return protectRenderedText(details.String())
}