1 files changed, 74 insertions, 0 deletions
diff --git a/internal/tmuxedit/send.go b/internal/tmuxedit/send.go
new file mode 100644
index 0000000..b85f7d3
--- /dev/null
+++ b/internal/tmuxedit/send.go
@@ -0,0 +1,74 @@
+package tmuxedit
+
+import (
+	"fmt"
+	"strings"
+)
+
+// sendKeys is the seam for `tmux send-keys`. Override in tests.
+var sendKeys = func(paneID string, keys ...string) error {
+	args := append([]string{"send-keys", "-t", paneID}, keys...)
+	_, err := runCommand("tmux", args...)
+	if err != nil {
+		return fmt.Errorf("send-keys failed: %w", err)
+	}
+	return nil
+}
+
+// deduplicateText removes the original (pre-filled) text from the edited
+// result. If the user kept the original and appended, only the new text is
+// returned. If the user rewrote everything, the full new text is returned.
+func deduplicateText(original, edited string) string {
+	original = strings.TrimSpace(original)
+	edited = strings.TrimSpace(edited)
+	if edited == "" {
+		return ""
+	}
+	if original == "" {
+		return edited
+	}
+	// If the edited text starts with the original, return only the appended part
+	if strings.HasPrefix(edited, original) {
+		appended := strings.TrimSpace(edited[len(original):])
+		if appended != "" {
+			return appended
+		}
+		// User didn't change anything; return empty to signal no-op
+		return ""
+	}
+	// User rewrote the prompt; return the full new text
+	return edited
+}
+
+// sendTextToPane sends the given text to the target pane. It optionally
+// clears existing input first (using the agent's ClearKeys), then sends
+// text line-by-line using the agent's NewlineKeys between lines.
+func sendTextToPane(paneID, text string, agent AgentConfig) error {
+	if strings.TrimSpace(text) == "" {
+		return nil
+	}
+	// Clear existing input if configured
+	if agent.ClearFirst && agent.ClearKeys != "" {
+		if err := sendKeys(paneID, agent.ClearKeys); err != nil {
+			return fmt.Errorf("clear failed: %w", err)
+		}
+	}
+	// Send text line by line, inserting newline keys between lines
+	lines := strings.Split(text, "\n")
+	for i, line := range lines {
+		if err := sendKeys(paneID, line); err != nil {
+			return fmt.Errorf("send line %d failed: %w", i, err)
+		}
+		// Insert inter-line newline (except after the last line)
+		if i < len(lines)-1 {
+			nlKey := agent.NewlineKeys
+			if nlKey == "" {
+				nlKey = "Enter" // fallback for agents without shift-enter
+			}
+			if err := sendKeys(paneID, nlKey); err != nil {
+				return fmt.Errorf("newline after line %d failed: %w", i, err)
+			}
+		}
+	}
+	return nil
+}