package editor

import (
	"testing"
)

// ==================================================
// P0: Basic Recording Tests
// ==================================================

func TestDotOperatorRecording(t *testing.T) {
	t.Run("records simple delete", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "x")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		if len(keys) != 1 || keys[0] != "x" {
			t.Errorf("LastChangeKeys() = %v, want [\"x\"]", keys)
		}

		// Also verify . register
		reg, ok := m.GetRegister('.')
		if !ok {
			t.Fatal("dot register not found")
		}
		if reg.Content[0] != "x" {
			t.Errorf("dot register = %q, want \"x\"", reg.Content[0])
		}
	})

	t.Run("records operator motion", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello world"}))
		sendKeys(tm, "d", "w")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		if len(keys) != 2 || keys[0] != "d" || keys[1] != "w" {
			t.Errorf("LastChangeKeys() = %v, want [\"d\", \"w\"]", keys)
		}
	})

	t.Run("records double press operator", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello", "world"}))
		sendKeys(tm, "d", "d")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		if len(keys) != 2 || keys[0] != "d" || keys[1] != "d" {
			t.Errorf("LastChangeKeys() = %v, want [\"d\", \"d\"]", keys)
		}
	})

	t.Run("records visual operation", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"line1", "line2", "line3"}))
		sendKeys(tm, "V", "j", "x")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		if len(keys) != 3 || keys[0] != "V" || keys[1] != "j" || keys[2] != "x" {
			t.Errorf("LastChangeKeys() = %v, want [\"V\", \"j\", \"x\"]", keys)
		}
	})

	t.Run("records insert mode", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "i", "X", "Y", "Z", "esc")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		if len(keys) != 5 || keys[0] != "i" || keys[1] != "X" || keys[2] != "Y" || keys[3] != "Z" || keys[4] != "esc" {
			t.Errorf("LastChangeKeys() = %v, want [\"i\", \"X\", \"Y\", \"Z\", \"esc\"]", keys)
		}
	})
}

// ==================================================
// P0: Non-Recording Tests
// ==================================================

func TestDotOperatorNonRecording(t *testing.T) {
	t.Run("does not record pure motions", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"line1", "line2", "line3", "line4"}))
		sendKeys(tm, "k", "k", "k")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Pure motions should result in empty recording
		if len(keys) != 0 {
			t.Errorf("LastChangeKeys() = %v, want []", keys)
		}
	})

	t.Run("does not record dot operator itself", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "x", ".", ".")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Should still be just ["x"], not ["x", ".", "."]
		if len(keys) != 1 || keys[0] != "x" {
			t.Errorf("LastChangeKeys() = %v, want [\"x\"]", keys)
		}
	})

	t.Run("does not record command mode entry", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, ":")
		sendKeys(tm, "esc") // Exit command mode

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Command mode entry should not record
		if len(keys) != 0 {
			t.Errorf("LastChangeKeys() = %v, want []", keys)
		}
	})

	t.Run("does not record visual mode entry without action", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "v", "esc")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Just entering and exiting visual mode should not record
		if len(keys) != 0 {
			t.Errorf("LastChangeKeys() = %v, want []", keys)
		}
	})
}

// ==================================================
// P0: Basic Replay Tests
// ==================================================

func TestDotOperatorReplay(t *testing.T) {
	t.Run("repeats simple delete", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "x")  // "ello"
		sendKeys(tm, ".")  // "llo"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().Line(0) != "llo" {
			t.Errorf("buffer = %q, want \"llo\"", m.ActiveBuffer().Line(0))
		}
	})

	t.Run("repeats operator motion", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"one two three"}))
		sendKeys(tm, "d", "w")  // "two three"
		sendKeys(tm, ".")       // "three"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().Line(0) != "three" {
			t.Errorf("buffer = %q, want \"three\"", m.ActiveBuffer().Line(0))
		}
	})

	t.Run("repeats double press operator", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"line1", "line2", "line3"}))
		sendKeys(tm, "d", "d")  // Delete first line -> "line2", "line3"
		sendKeys(tm, ".")       // Delete next line -> "line3"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.ActiveBuffer().LineCount())
		}
		if m.ActiveBuffer().Line(0) != "line3" {
			t.Errorf("buffer = %q, want \"line3\"", m.ActiveBuffer().Line(0))
		}
	})
}

// ==================================================
// P1: Recording Replacement Tests
// ==================================================

func TestDotOperatorRecordingReplacement(t *testing.T) {
	t.Run("new action replaces old recording", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello world"}))
		sendKeys(tm, "x")       // Record ["x"]
		sendKeys(tm, "l", "l")  // Motions clear recording buffer but don't save
		sendKeys(tm, "d", "w")  // Record ["d", "w"]

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Should be the latest action ["d", "w"], not ["x"]
		if len(keys) != 2 || keys[0] != "d" || keys[1] != "w" {
			t.Errorf("LastChangeKeys() = %v, want [\"d\", \"w\"]", keys)
		}
	})

	t.Run("motions clear recording without saving", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"line1", "line2", "line3", "line4"}))
		sendKeys(tm, "x")             // Record ["x"]
		sendKeys(tm, "j", "j", "j")   // Motions don't overwrite saved recording
		sendKeys(tm, "d", "d")        // New action replaces

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Should be ["d", "d"] from the last modifying action
		if len(keys) != 2 || keys[0] != "d" || keys[1] != "d" {
			t.Errorf("LastChangeKeys() = %v, want [\"d\", \"d\"]", keys)
		}
	})
}

// ==================================================
// P1: Visual Mode Tests
// ==================================================

func TestDotOperatorVisualMode(t *testing.T) {
	t.Run("repeats visual line operation", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"a", "b", "c", "d", "e"}))
		sendKeys(tm, "V", "j", "x")  // Delete lines 0-1 -> "c", "d", "e"
		// Cursor should be at line 0 after deletion
		sendKeys(tm, ".")            // Repeat -> delete next 2 lines -> "e"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.ActiveBuffer().LineCount())
		}
		if m.ActiveBuffer().Line(0) != "e" {
			t.Errorf("buffer = %q, want \"e\"", m.ActiveBuffer().Line(0))
		}
	})
}

// ==================================================
// P1: Insert Mode Tests
// ==================================================

func TestDotOperatorInsertMode(t *testing.T) {
	t.Run("repeats insert mode operation", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "i", "X", "Y", "Z", "esc")  // "XYZhello", cursor at col 2 (on Z)
		// Move cursor after XYZ (to col 3, between Z and h)
		sendKeys(tm, "l")
		sendKeys(tm, ".")                        // Should insert XYZ again at col 3

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().Line(0) != "XYZXYZhello" {
			t.Errorf("buffer = %q, want \"XYZXYZhello\"", m.ActiveBuffer().Line(0))
		}
	})
}

// ==================================================
// P1: Multiple Repeat Tests
// ==================================================

func TestDotOperatorMultipleRepeats(t *testing.T) {
	t.Run("dot can be used multiple times", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello world foo bar"}))
		sendKeys(tm, "d", "w")  // "world foo bar"
		sendKeys(tm, ".")       // "foo bar"
		sendKeys(tm, ".")       // "bar"
		sendKeys(tm, ".")       // ""

		m := getFinalModel(t, tm)
		line := m.ActiveBuffer().Line(0)
		// After deleting 4 words, should be empty or just whitespace
		if line != "" && line != " " {
			t.Errorf("buffer = %q, want empty or space", line)
		}
	})
}

// ==================================================
// P2: Edge Cases
// ==================================================

func TestDotOperatorEdgeCases(t *testing.T) {
	t.Run("repeat at start of file", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "x")  // "ello"
		sendKeys(tm, ".")  // "llo"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().Line(0) != "llo" {
			t.Errorf("buffer = %q, want \"llo\"", m.ActiveBuffer().Line(0))
		}
	})

	t.Run("repeat after undo", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello world"}))
		sendKeys(tm, "x")  // "ello world"
		sendKeys(tm, "u")  // Undo -> "hello world"
		sendKeys(tm, ".")  // Repeat should still work -> "ello world"

		m := getFinalModel(t, tm)
		if m.ActiveBuffer().Line(0) != "ello world" {
			t.Errorf("buffer = %q, want \"ello world\"", m.ActiveBuffer().Line(0))
		}
	})

	t.Run("repeat with no recorded change", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, ".")  // Dot with nothing recorded

		m := getFinalModel(t, tm)
		// Should not crash, buffer should be unchanged
		if m.ActiveBuffer().Line(0) != "hello" {
			t.Errorf("buffer = %q, want \"hello\"", m.ActiveBuffer().Line(0))
		}
	})
}

// ==================================================
// P2: Integration with Counts
// ==================================================

func TestDotOperatorWithCounts(t *testing.T) {
	t.Run("recording includes count", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello world"}))
		sendKeys(tm, "3", "x")

		m := getFinalModel(t, tm)
		keys := m.LastChangeKeys()
		// Should record both the count and the action
		if len(keys) != 2 || keys[0] != "3" || keys[1] != "x" {
			t.Errorf("LastChangeKeys() = %v, want [\"3\", \"x\"]", keys)
		}
	})

	t.Run("repeat preserves count", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"hello"}))
		sendKeys(tm, "3", "x")  // Delete 3 chars -> "lo"
		sendKeys(tm, ".")       // Should delete 3 more (or try to)

		m := getFinalModel(t, tm)
		// After deleting 3 + 3 = 6 chars, should be empty or have no chars left
		if m.ActiveBuffer().Line(0) != "" {
			t.Errorf("buffer = %q, want empty", m.ActiveBuffer().Line(0))
		}
	})
}

// ==================================================
// P2: Complex Sequences
// ==================================================

func TestDotOperatorComplexSequences(t *testing.T) {
	t.Run("complex sequence of operations", func(t *testing.T) {
		tm := newTestModel(t, WithLines([]string{"line1", "line2", "line3"}))
		sendKeys(tm, "x")       // Delete 'l' from line1 -> ["ine1", "line2", "line3"]
		sendKeys(tm, "j", "j")  // Move to line 2
		sendKeys(tm, "d", "d")  // Delete line 2 (line3) -> ["ine1", "line2"], cursor at line 1
		sendKeys(tm, "k")       // Move up to line 0
		sendKeys(tm, ".")       // Repeat dd - deletes line 0 (ine1) -> ["line2"]

		m := getFinalModel(t, tm)
		// After the sequence, dd was recorded and repeated at line 0, deleting it
		if m.ActiveBuffer().LineCount() != 1 {
			t.Errorf("LineCount() = %d, want 1", m.ActiveBuffer().LineCount())
		}
		if m.ActiveBuffer().Line(0) != "line2" {
			t.Errorf("buffer = %q, want \"line2\"", m.ActiveBuffer().Line(0))
		}
	})
}