package gio

import (
	"image"

	"gioui.org/layout"
	"gioui.org/op/paint"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"

	"softbox.local/core/application"
)

// AppShell is the Legacy software catalog window.
type AppShell struct {
	edition string
	model   *application.CatalogListModel

	search       widget.Editor
	appList      layout.List
	categoryList layout.List

	viewAll       widget.Clickable
	viewInstalled widget.Clickable
	viewUpdates   widget.Clickable
	resetFilters  widget.Clickable
	closeDetail   widget.Clickable

	categoryControls map[string]*widget.Clickable
	rows             map[string]*rowControls
	icons            map[string]paint.ImageOp
	iconReferences   map[string]string
	iconRequests     map[string]application.IconEventIdentity
	iconApplied      map[string]application.IconEventIdentity
	iconFailures     map[string]iconFailureState
	catalogState     catalogPresentationState
	lastRendered     int
	detailRendered   bool
}

// NewAppShell creates the catalog shell with an optional in-memory snapshot.
func NewAppShell(
	edition string,
	items ...application.CatalogListItem,
) *AppShell {
	shell := &AppShell{
		edition:          edition,
		model:            application.NewCatalogListModel(nil),
		appList:          layout.List{Axis: layout.Vertical},
		categoryList:     layout.List{Axis: layout.Horizontal},
		categoryControls: make(map[string]*widget.Clickable),
		rows:             make(map[string]*rowControls),
		icons:            make(map[string]paint.ImageOp),
		iconReferences:   make(map[string]string),
		iconRequests:     make(map[string]application.IconEventIdentity),
		iconApplied:      make(map[string]application.IconEventIdentity),
		iconFailures:     make(map[string]iconFailureState),
	}
	shell.search.SingleLine = true
	shell.SetItems(items)
	if len(items) == 0 {
		shell.catalogState = catalogStateLoading
	}
	return shell
}

// ApplyIcon stores a decoded image for future Layout calls.
// It is UI-goroutine-only; background workers must publish application events.
func (shell *AppShell) ApplyIcon(appID string, icon image.Image) {
	delete(shell.iconApplied, appID)
	delete(shell.iconFailures, appID)
	if icon == nil {
		delete(shell.icons, appID)
		return
	}
	shell.icons[appID] = paint.NewImageOp(icon)
}

// SetItems applies a prepared, IO-free catalog/status snapshot.
func (shell *AppShell) SetItems(items []application.CatalogListItem) {
	shell.model.SetItems(items)
	shell.catalogState = catalogStateReady

	nextRows := make(map[string]*rowControls, len(items))
	nextIcons := make(map[string]paint.ImageOp, len(items))
	nextReferences := make(map[string]string, len(items))
	nextRequests := make(map[string]application.IconEventIdentity, len(items))
	nextApplied := make(map[string]application.IconEventIdentity, len(items))
	nextFailures := make(map[string]iconFailureState, len(items))
	for _, item := range items {
		controls := shell.rows[item.ID]
		if controls == nil {
			controls = new(rowControls)
		}
		nextRows[item.ID] = controls
		reference := canonicalIconReference(item.IconRef)
		nextReferences[item.ID] = reference
		if previous, exists := shell.iconReferences[item.ID]; exists && previous == reference {
			if icon, exists := shell.icons[item.ID]; exists {
				nextIcons[item.ID] = icon
			}
			if request, exists := shell.iconRequests[item.ID]; exists && request.Reference == reference {
				nextRequests[item.ID] = request
			}
			if applied, exists := shell.iconApplied[item.ID]; exists && applied.Reference == reference {
				nextApplied[item.ID] = applied
			}
			if failure, exists := shell.iconFailures[item.ID]; exists &&
				failure.Identity.Reference == reference {
				nextFailures[item.ID] = failure
			}
		}
	}
	shell.rows = nextRows
	shell.icons = nextIcons
	shell.iconReferences = nextReferences
	shell.iconRequests = nextRequests
	shell.iconApplied = nextApplied
	shell.iconFailures = nextFailures

	nextCategories := make(map[string]*widget.Clickable)
	for _, category := range append([]string{""}, shell.model.Categories()...) {
		control := shell.categoryControls[category]
		if control == nil {
			control = new(widget.Clickable)
		}
		nextCategories[category] = control
	}
	shell.categoryControls = nextCategories
}

// Layout drains input first and performs no disk, network or hash IO.
func (shell *AppShell) Layout(gtx layout.Context, theme *material.Theme) layout.Dimensions {
	shell.drainInput(gtx)
	shell.lastRendered = 0
	shell.detailRendered = false
	paint.Fill(gtx.Ops, shellColors.background)

	return layout.UniformInset(unit.Dp(16)).Layout(gtx, func(gtx layout.Context) layout.Dimensions {
		return layout.Flex{Axis: layout.Vertical}.Layout(
			gtx,
			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
				return shell.layoutHeader(gtx, theme)
			}),
			layout.Rigid(layout.Spacer{Height: unit.Dp(12)}.Layout),
			layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
				return shell.layoutContent(gtx, theme)
			}),
			layout.Rigid(layout.Spacer{Height: unit.Dp(8)}.Layout),
			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
				label := material.Caption(
					theme,
					shell.catalogStatusText()+" · "+shell.edition+" · Legacy · Windows 7 SP1 x64",
				)
				label.Color = shellColors.secondary
				return label.Layout(gtx)
			}),
		)
	})
}

func (shell *AppShell) drainInput(gtx layout.Context) {
	for {
		if _, ok := shell.search.Update(gtx); !ok {
			break
		}
	}
	shell.model.SetQuery(shell.search.Text())
	for shell.viewAll.Clicked(gtx) {
		shell.model.SetView(application.CatalogViewAll)
	}
	for shell.viewInstalled.Clicked(gtx) {
		shell.model.SetView(application.CatalogViewInstalled)
	}
	for shell.viewUpdates.Clicked(gtx) {
		shell.model.SetView(application.CatalogViewUpdates)
	}
	for category, control := range shell.categoryControls {
		for control.Clicked(gtx) {
			shell.model.SetCategory(category)
		}
	}
	for appID, controls := range shell.rows {
		for controls.open.Clicked(gtx) {
			shell.model.Select(appID)
		}
	}
	for shell.resetFilters.Clicked(gtx) {
		shell.search.SetText("")
		shell.model.ResetFilters()
	}
	for shell.closeDetail.Clicked(gtx) {
		shell.model.Select("")
	}
}