// Fenrir console screen reader.
// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

package review

import (
	"testing"

	"git.stormux.org/storm/fenrir/internal/command"
	"git.stormux.org/storm/fenrir/internal/presentation"
	"git.stormux.org/storm/fenrir/internal/screen"
)

func TestScreenRangesIncludeCursorAndPreserveRows(t *testing.T) {
	for _, testCase := range []struct {
		name          string
		lines         []string
		x, y          int
		before, after string
	}{
		{"unicode middle", []string{"  first", "", "café 界!", "  last"}, 5, 2, "  first\n\ncafé 界", "界!\n  last"},
		{"top left", []string{"alpha", "bravo"}, 0, 0, "a", "alpha\nbravo"},
		{"bottom right", []string{"alpha", "bravo"}, 19, 1, "alpha\nbravo", "blank"},
		{"one row", []string{"ab界cd"}, 2, 0, "ab界", "界cd"},
		{"blank row", []string{"alpha", "", "last"}, 7, 1, "alpha\n", "\nlast"},
		{"trailing padding", []string{"alpha", "  last"}, 14, 0, "alpha", "\n  last"},
		{"blank screen", []string{"", ""}, 4, 1, "blank", "blank"},
		{"literal blank", []string{"blank"}, 0, 0, "b", "blank"},
		{"last visible character", []string{"界"}, 0, 0, "界", "界"},
	} {
		t.Run(testCase.name, func(t *testing.T) {
			var review Review
			snapshot := fixture(testCase.lines...)
			snapshot.X, snapshot.Y = testCase.x, testCase.y
			review.Update(snapshot)
			for _, action := range []struct {
				id   command.ID
				want string
			}{
				{command.ScreenBeforeCursor, testCase.before},
				{command.ScreenAfterCursor, testCase.after},
			} {
				result := review.Execute(action.id)
				if got := result.Text; got != action.want {
					t.Fatalf("%s: got %q, want %q", action.id, got, action.want)
				}
				wantCue := presentation.Cue("")
				if testCase.name == "blank screen" || testCase.name == "bottom right" && action.id == command.ScreenAfterCursor {
					wantCue = presentation.Blank
				}
				if result.Cue != wantCue {
					t.Fatalf("%s: cue %q, want %q", action.id, result.Cue, wantCue)
				}
				if review.x != testCase.x || review.y != testCase.y || review.screen.X != testCase.x || review.screen.Y != testCase.y {
					t.Fatal("range action moved a cursor")
				}
			}
		})
	}
}

func TestScreenRangesPreferDetachedReviewAndKeepTableScope(t *testing.T) {
	var review Review
	snapshot := fixture("Name | City", "Ana | Paris", "Zoë | Rome")
	snapshot.X, snapshot.Y = 7, 0
	review.Update(snapshot)
	review.Execute(command.CurrentChar)
	review.Set_mark()
	review.Set_table_mode(true)
	review.Execute(command.NextLine)
	// Application cursor moves while detached review stays on the second row.
	snapshot.X, snapshot.Y = 0, 2
	review.Update(snapshot)
	for _, action := range []struct {
		id   command.ID
		want string
	}{
		{command.ScreenBeforeCursor, "Name | City\nAna | Pa"},
		{command.ScreenAfterCursor, "aris\nZoë | Rome"},
	} {
		if got := review.Execute(action.id).Text; got != action.want {
			t.Fatalf("%s: %q, want %q", action.id, got, action.want)
		}
		if review.x != 7 || review.y != 1 || review.tableColumn != 1 || review.markCount != 1 || !review.Active() {
			t.Fatal("range action disturbed review, column or mark state")
		}
	}
	review.Execute(command.FollowCursor)
	if got := review.Execute(command.ScreenAfterCursor).Text; got != "Zoë | Rome" {
		t.Fatal("follow did not restore application cursor scope", got)
	}
	// Screen generation and geometry changes must discard the old anchor.
	snapshot = fixture("new")
	snapshot.Generation = 1
	review.Update(snapshot)
	if got := review.Execute(command.ScreenBeforeCursor).Text; got != "n" {
		t.Fatal("range kept an anchor from another screen", got)
	}
	review.Update(screen.Snapshot{})
	for _, id := range []command.ID{command.ScreenBeforeCursor, command.ScreenAfterCursor} {
		result := review.Execute(id)
		if got := result.Text; got != "no text console" || result.Cue != presentation.Error {
			t.Fatal("inactive screen", got, result.Cue)
		}
	}
}