package ui

import (
	"strings"

	"github.com/nvm/kportal/internal/k8s"
)

// filterStrings filters a slice of strings by a search filter (case-insensitive substring match)
func filterStrings(items []string, filter string) []string {
	if filter == "" {
		return items
	}
	filtered := []string{}
	filterLower := strings.ToLower(filter)
	for _, item := range items {
		if strings.Contains(strings.ToLower(item), filterLower) {
			filtered = append(filtered, item)
		}
	}
	return filtered
}

// matchesFilter checks if a string matches the filter (case-insensitive substring match)
func matchesFilter(item, filter string) bool {
	if filter == "" {
		return true
	}
	return strings.Contains(strings.ToLower(item), strings.ToLower(filter))
}

// ViewMode represents the current view state of the UI
type ViewMode int

const (
	ViewModeMain ViewMode = iota
	ViewModeAddWizard
	ViewModeRemoveWizard
	ViewModeBenchmark
	ViewModeHTTPLog
)

// InputMode represents whether the wizard is in list selection or text input mode
type InputMode int

const (
	InputModeList InputMode = iota
	InputModeText
)

// AddWizardStep represents the current step in the add wizard flow
type AddWizardStep int

const (
	StepSelectContext AddWizardStep = iota
	StepSelectNamespace
	StepSelectResourceType
	StepEnterResource
	StepEnterRemotePort
	StepEnterLocalPort
	StepConfirmation
	StepSuccess
)

// ConfirmationFocus represents what the user is focused on in confirmation step
type ConfirmationFocus int

const (
	FocusAlias ConfirmationFocus = iota
	FocusButtons
)

// ResourceType represents the type of Kubernetes resource to forward to
type ResourceType int

const (
	ResourceTypePodPrefix ResourceType = iota
	ResourceTypePodSelector
	ResourceTypeService
)

// String returns a human-readable name for the resource type
func (r ResourceType) String() string {
	switch r {
	case ResourceTypePodPrefix:
		return "Pod (by name prefix)"
	case ResourceTypePodSelector:
		return "Pod (by label selector)"
	case ResourceTypeService:
		return "Service"
	default:
		return "Unknown"
	}
}

// Description returns a description of the resource type
func (r ResourceType) Description() string {
	switch r {
	case ResourceTypePodPrefix:
		return "Recommended for specific pod instances"
	case ResourceTypePodSelector:
		return "Flexible, survives pod restarts automatically"
	case ResourceTypeService:
		return "Most stable, load-balanced"
	default:
		return ""
	}
}

// AddWizardState maintains the state for the add port forward wizard
type AddWizardState struct {
	error                error
	resourceValue        string
	originalID           string
	portCheckMsg         string
	alias                string
	textInput            string
	searchFilter         string
	selector             string
	selectedContext      string
	selectedNamespace    string
	pods                 []k8s.PodInfo
	contexts             []string
	detectedPorts        []k8s.PortInfo
	matchingPods         []k8s.PodInfo
	services             []k8s.ServiceInfo
	namespaces           []string
	scrollOffset         int
	selectedResourceType ResourceType
	step                 AddWizardStep
	localPort            int
	cursor               int
	remotePort           int
	inputMode            InputMode
	confirmationFocus    ConfirmationFocus
	portAvailable        bool
	isEditing            bool
	loading              bool
}

// newAddWizardState creates a new add wizard state initialized to the first step
func newAddWizardState() *AddWizardState {
	return &AddWizardState{
		step:      StepSelectContext,
		inputMode: InputModeList,
		cursor:    0,
		contexts:  []string{},
	}
}

// moveCursor moves the cursor up or down in list selection mode
func (w *AddWizardState) moveCursor(delta int) {
	if w.inputMode != InputModeList {
		return
	}

	var maxItems int

	switch w.step {
	case StepSelectContext:
		maxItems = len(w.getFilteredContexts())
	case StepSelectNamespace:
		maxItems = len(w.getFilteredNamespaces())
	case StepSelectResourceType:
		maxItems = 3 // Three resource types
	case StepEnterResource:
		if w.selectedResourceType == ResourceTypeService {
			maxItems = len(w.getFilteredServices())
		}
	case StepEnterRemotePort:
		if len(w.detectedPorts) > 0 {
			maxItems = len(w.detectedPorts) + 1 // +1 for "Manual entry" option
		}
	}

	w.cursor += delta
	if w.cursor < 0 {
		w.cursor = 0
	}
	if w.cursor >= maxItems && maxItems > 0 {
		w.cursor = maxItems - 1
	}

	// Adjust scroll offset to keep cursor visible
	// Viewport shows max 20 items at a time
	const viewportHeight = 20

	// If cursor moved below visible area, scroll down
	if w.cursor >= w.scrollOffset+viewportHeight {
		w.scrollOffset = w.cursor - viewportHeight + 1
	}

	// If cursor moved above visible area, scroll up
	if w.cursor < w.scrollOffset {
		w.scrollOffset = w.cursor
	}

	// Ensure scroll offset is valid
	if w.scrollOffset < 0 {
		w.scrollOffset = 0
	}
}

// handleTextInput handles a single character input in text mode
func (w *AddWizardState) handleTextInput(char rune) {
	// Note: Caller already checks if text input is allowed (inputMode or confirmation step)
	// so we don't need to check inputMode here

	// Handle backspace
	if char == 127 || char == 8 {
		if len(w.textInput) > 0 {
			w.textInput = w.textInput[:len(w.textInput)-1]
		}
		return
	}

	// Only allow printable characters
	if char >= 32 && char < 127 {
		w.textInput += string(char)
	}
}

// clearTextInput clears the text input field
func (w *AddWizardState) clearTextInput() {
	w.textInput = ""
}

// RemoveWizardState maintains the state for the remove port forward wizard
type RemoveWizardState struct {
	selected      map[int]bool
	forwards      []RemovableForward
	cursor        int
	confirmCursor int
	confirming    bool
}

// RemovableForward represents a forward that can be removed
type RemovableForward struct {
	ID        string
	Context   string
	Namespace string
	Alias     string
	Resource  string
	Selector  string
	Port      int
	LocalPort int
}

// moveCursor moves the cursor up or down
func (w *RemoveWizardState) moveCursor(delta int) {
	if w.confirming {
		// Move between Yes/No in confirmation
		w.confirmCursor += delta
		if w.confirmCursor < 0 {
			w.confirmCursor = 0
		}
		if w.confirmCursor > 1 {
			w.confirmCursor = 1
		}
	} else {
		// Move between forwards
		w.cursor += delta
		if w.cursor < 0 {
			w.cursor = 0
		}
		if w.cursor >= len(w.forwards) {
			w.cursor = len(w.forwards) - 1
		}
	}
}

// toggleSelection toggles the selection of the current forward
func (w *RemoveWizardState) toggleSelection() {
	if w.confirming {
		return
	}
	w.selected[w.cursor] = !w.selected[w.cursor]
}

// selectAll selects all forwards for removal
func (w *RemoveWizardState) selectAll() {
	if w.confirming {
		return
	}
	for i := range w.forwards {
		w.selected[i] = true
	}
}

// selectNone deselects all forwards
func (w *RemoveWizardState) selectNone() {
	if w.confirming {
		return
	}
	w.selected = make(map[int]bool)
}

// getSelectedCount returns the number of selected forwards
func (w *RemoveWizardState) getSelectedCount() int {
	count := 0
	for _, selected := range w.selected {
		if selected {
			count++
		}
	}
	return count
}

// getSelectedForwards returns a list of selected forwards
func (w *RemoveWizardState) getSelectedForwards() []RemovableForward {
	selected := make([]RemovableForward, 0)
	for i, fwd := range w.forwards {
		if w.selected[i] {
			selected = append(selected, fwd)
		}
	}
	return selected
}

// getFilteredContexts returns contexts filtered by search string
func (w *AddWizardState) getFilteredContexts() []string {
	if w.searchFilter == "" {
		return w.contexts
	}
	return filterStrings(w.contexts, w.searchFilter)
}

// getFilteredNamespaces returns namespaces filtered by search string
func (w *AddWizardState) getFilteredNamespaces() []string {
	if w.searchFilter == "" {
		return w.namespaces
	}
	return filterStrings(w.namespaces, w.searchFilter)
}

// getFilteredServices returns services filtered by search string
func (w *AddWizardState) getFilteredServices() []k8s.ServiceInfo {
	if w.searchFilter == "" {
		return w.services
	}
	filtered := []k8s.ServiceInfo{}
	for _, svc := range w.services {
		if matchesFilter(svc.Name, w.searchFilter) {
			filtered = append(filtered, svc)
		}
	}
	return filtered
}

// clearSearchFilter clears the search filter and resets cursor/scroll
func (w *AddWizardState) clearSearchFilter() {
	w.searchFilter = ""
	w.cursor = 0
	w.scrollOffset = 0
}

// resetInput clears text input, search filter, and error state.
// Use this when navigating between wizard steps.
func (w *AddWizardState) resetInput() {
	w.textInput = ""
	w.searchFilter = ""
	w.cursor = 0
	w.scrollOffset = 0
	w.error = nil
}

// BenchmarkStep represents the current step in the benchmark wizard
type BenchmarkStep int

const (
	BenchmarkStepConfig BenchmarkStep = iota
	BenchmarkStepRunning
	BenchmarkStepResults
)

// BenchmarkState maintains the state for the benchmark wizard
type BenchmarkState struct {
	error        error
	results      *BenchmarkResults
	cancelFunc   func()
	progressCh   chan BenchmarkProgressMsg
	textInput    string
	forwardID    string
	forwardAlias string
	urlPath      string
	method       string
	cursor       int
	progress     int
	total        int
	step         BenchmarkStep
	requests     int
	concurrency  int
	localPort    int
	running      bool
}

// BenchmarkResults holds benchmark results for display
type BenchmarkResults struct {
	StatusCodes   map[int]int
	TotalRequests int
	Successful    int
	Failed        int
	MinLatency    float64
	MaxLatency    float64
	AvgLatency    float64
	P50Latency    float64
	P95Latency    float64
	P99Latency    float64
	Throughput    float64
	BytesRead     int64
}

// newBenchmarkState creates a new benchmark state for a forward
func newBenchmarkState(forwardID, alias string, localPort int) *BenchmarkState {
	return &BenchmarkState{
		step:         BenchmarkStepConfig,
		forwardID:    forwardID,
		forwardAlias: alias,
		localPort:    localPort,
		urlPath:      "/",
		method:       "GET",
		concurrency:  10,
		requests:     100,
		cursor:       0,
	}
}

// HTTPLogFilterMode represents the active filter type
type HTTPLogFilterMode int

const (
	HTTPLogFilterNone HTTPLogFilterMode = iota
	HTTPLogFilterText
	HTTPLogFilterNon200
	HTTPLogFilterErrors // 4xx and 5xx only
)

// HTTPLogState maintains the state for HTTP log viewing
type HTTPLogState struct {
	forwardID     string
	forwardAlias  string
	filterText    string
	copyMessage   string
	entries       []HTTPLogEntry
	cursor        int
	scrollOffset  int
	filterMode    HTTPLogFilterMode
	detailScroll  int
	autoScroll    bool
	filterActive  bool
	showingDetail bool
}

// HTTPLogEntry represents a single HTTP log entry for display
type HTTPLogEntry struct {
	RequestHeaders  map[string]string
	ResponseHeaders map[string]string
	Method          string
	RequestID       string
	Path            string
	Direction       string
	Timestamp       string
	RequestBody     string
	ResponseBody    string
	Error           string
	StatusCode      int
	LatencyMs       int64
	BodySize        int
}

// newHTTPLogState creates a new HTTP log viewing state
func newHTTPLogState(forwardID, alias string) *HTTPLogState {
	return &HTTPLogState{
		forwardID:    forwardID,
		forwardAlias: alias,
		entries:      make([]HTTPLogEntry, 0),
		autoScroll:   true,
		filterMode:   HTTPLogFilterNone,
	}
}

// getFilteredEntries returns entries matching the current filter
// Only returns entries with status codes (responses) since requests don't have useful info
func (s *HTTPLogState) getFilteredEntries() []HTTPLogEntry {
	filtered := make([]HTTPLogEntry, 0, len(s.entries))
	filterLower := strings.ToLower(s.filterText)

	for _, entry := range s.entries {
		// Only show entries with status codes (completed responses)
		// Requests, streaming connections, and errors without status are filtered out
		if entry.StatusCode == 0 {
			continue
		}

		// Apply filter mode
		switch s.filterMode {
		case HTTPLogFilterNon200:
			if entry.StatusCode >= 200 && entry.StatusCode < 300 {
				continue
			}
		case HTTPLogFilterErrors:
			if entry.StatusCode < 400 {
				continue
			}
		}

		// Apply text filter
		if s.filterText != "" {
			matchPath := strings.Contains(strings.ToLower(entry.Path), filterLower)
			matchMethod := strings.Contains(strings.ToLower(entry.Method), filterLower)
			if !matchPath && !matchMethod {
				continue
			}
		}

		filtered = append(filtered, entry)
	}

	return filtered
}

// getFilterModeLabel returns a label for the current filter mode
func (s *HTTPLogState) getFilterModeLabel() string {
	switch s.filterMode {
	case HTTPLogFilterNone:
		return "All"
	case HTTPLogFilterText:
		return "Text"
	case HTTPLogFilterNon200:
		return "Non-2xx"
	case HTTPLogFilterErrors:
		return "Errors (4xx/5xx)"
	default:
		return "All"
	}
}