package tui

import (
	"errors"

	tea "github.com/charmbracelet/bubbletea"

	"proxyctl/internal/app"
)

type operationError struct {
	status app.OperationStatus
	detail string
}

// operationCoordinator owns the complete interactive operation lifecycle. The
// root Model delegates stream consumption, progress, confirmation, current
// error, and deferred-exit state here instead of mirroring those states.
type operationCoordinator struct {
	active             bool
	intent             app.Intent
	updates            <-chan app.OperationUpdate
	progress           map[string]app.TargetProgressPhase
	status             app.OperationStatus
	currentError       *operationError
	errorExpanded      bool
	errorOffset        int
	confirmation       *app.Confirmation
	confirmationDialog confirmationDialog
	confirmationIntent *app.Intent
	quitRequested      bool
}

type operationProgress struct {
	update  app.OperationUpdate
	updates <-chan app.OperationUpdate
	closed  bool
}

func newOperationCoordinator() operationCoordinator {
	return operationCoordinator{progress: make(map[string]app.TargetProgressPhase)}
}

func waitForOperation(updates <-chan app.OperationUpdate) tea.Cmd {
	return func() tea.Msg {
		update, ok := <-updates
		if !ok {
			return operationProgress{updates: updates, closed: true}
		}
		return operationProgress{update: update, updates: updates}
	}
}

func (o *operationCoordinator) start(application app.InteractiveModule, intent app.Intent) (app.Snapshot, tea.Cmd, bool) {
	if o.quitRequested || o.active || o.confirmation != nil {
		o.status = app.OperationStatus{Kind: app.StatusBlocked, Summary: "Wait for the current operation to finish before starting another modification"}
		return application.Snapshot(), nil, false
	}
	stream := application.StartOperation(intent)
	o.active = true
	o.intent = intent
	o.updates = stream.Updates
	o.progress = make(map[string]app.TargetProgressPhase)
	if intent.TargetID != "" {
		o.progress[intent.TargetID] = app.TargetProgressRunning
	}
	o.status = app.OperationStatus{Kind: app.StatusProgress, Summary: operationStartingSummary(intent.Kind)}
	return stream.Snapshot, waitForOperation(stream.Updates), true
}

func operationStartingSummary(kind app.IntentKind) string {
	switch kind {
	case app.RefreshTargets:
		return "Checking Target availability and state…"
	case app.ActivateProfile:
		return "Changing Active Profile…"
	default:
		return "Starting Target mutation…"
	}
}

func (o *operationCoordinator) apply(update app.OperationUpdate) (firstFailedTargetID string) {
	status := update.Status()
	progress := update.Progress()
	for _, item := range progress {
		o.progress[item.TargetID] = item.Phase
		if item.Phase == app.TargetProgressSucceeded {
			o.resolveTargetError(item.TargetID)
		}
	}
	if status.Summary != "" {
		o.status = status
	}
	if update.IsSucceeded() {
		o.resolveTargetError(status.TargetID)
	}
	if update.IsFailed() {
		o.currentError = &operationError{status: status, detail: errorDetail(update.Err())}
		o.errorExpanded = false
		o.errorOffset = 0
		firstFailedTargetID = update.FirstFailedTargetID()
	}
	if request := update.Confirmation(); request != nil {
		intent := o.intent
		o.confirmation = request
		o.confirmationDialog = newConfirmationDialog(*request)
		o.confirmationIntent = &intent
	}
	if update.IsTerminal() {
		o.finish()
	}
	return firstFailedTargetID
}

func errorDetail(err error) string {
	if err == nil {
		return ""
	}
	return err.Error()
}

func (o *operationCoordinator) resolveTargetError(targetID string) {
	if targetID == "" || o.currentError == nil || o.currentError.status.TargetID != targetID {
		return
	}
	o.currentError = nil
	o.errorExpanded = false
	o.errorOffset = 0
}

func (o *operationCoordinator) finish() {
	o.active = false
	o.intent = app.Intent{}
	o.updates = nil
}

func (o *operationCoordinator) unexpectedClose() {
	o.status = app.OperationStatus{Kind: app.StatusError, Summary: "Operation ended without a final result"}
	o.currentError = &operationError{
		status: o.status,
		detail: "The Application operation stream closed before publishing a terminal result.",
	}
	o.errorExpanded = false
	o.errorOffset = 0
	o.finish()
}

func (o *operationCoordinator) acknowledgeError() {
	o.currentError = nil
	o.errorExpanded = false
	o.errorOffset = 0
	if o.status.Kind == app.StatusError {
		o.status = app.OperationStatus{}
	}
}

func (o *operationCoordinator) cancelConfirmation() {
	o.confirmation = nil
	o.confirmationDialog = confirmationDialog{}
	o.confirmationIntent = nil
	o.status = app.OperationStatus{}
}

func (o *operationCoordinator) confirmedIntent() (app.Intent, bool) {
	if o.confirmationIntent == nil {
		return app.Intent{}, false
	}
	intent := *o.confirmationIntent
	intent.Confirm = true
	o.confirmation = nil
	o.confirmationDialog = confirmationDialog{}
	o.confirmationIntent = nil
	return intent, true
}

func (o operationCoordinator) busy() bool {
	return o.quitRequested || o.active || o.confirmation != nil
}

func (o operationCoordinator) deferredQuit() tea.Cmd {
	if o.quitRequested && !o.active {
		return tea.Quit
	}
	return nil
}

func (o *operationCoordinator) requestQuit() tea.Cmd {
	o.quitRequested = true
	if o.active {
		return nil
	}
	return tea.Quit
}

func (o *operationCoordinator) fail(err error, summary string) {
	if err == nil {
		err = errors.New(summary)
	}
	o.status = app.OperationStatus{Kind: app.StatusError, Summary: summary}
	o.currentError = &operationError{status: o.status, detail: err.Error()}
	o.finish()
}