1 files changed, 212 insertions, 0 deletions
diff --git a/internal/tmuxedit/agent.go b/internal/tmuxedit/agent.go
new file mode 100644
index 0000000..2e07824
--- /dev/null
+++ b/internal/tmuxedit/agent.go
@@ -0,0 +1,212 @@
+// Package tmuxedit implements a tmux popup editor for composing AI agent prompts.
+// agent.go defines agent detection, prompt extraction, and noise stripping.
+package tmuxedit
+
+import (
+	"regexp"
+	"strings"
+
+	"codeberg.org/snonux/hexai/internal/appconfig"
+)
+
+// AgentConfig describes how to detect and interact with a specific AI agent
+// running in a tmux pane. All behavior is driven by regex patterns so new
+// agents can be added via config without code changes.
+type AgentConfig struct {
+	Name          string   // short key: "claude", "cursor", "amp"
+	DisplayName   string   // human-readable: "Claude Code"
+	DetectPattern string   // regex matched against pane content for auto-detection
+	PromptPattern string   // regex with capture group (1) to extract current prompt text
+	StripPatterns []string // substrings removed from extracted text
+	ClearFirst    bool     // whether to clear existing input before sending
+	ClearKeys     string   // tmux key sequence to clear input (e.g. "C-u")
+	NewlineKeys   string   // tmux key to insert a newline (e.g. "S-Enter")
+	SubmitKeys    string   // tmux key to submit the prompt (e.g. "Enter")
+}
+
+// builtinAgents returns the default set of agent configurations. These are
+// overridden/extended by user config in [tmux_edit.agents].
+func builtinAgents() []AgentConfig {
+	return []AgentConfig{
+		{
+			Name:          "claude",
+			DisplayName:   "Claude Code",
+			DetectPattern: `(?i)(claude|anthropic)`,
+			PromptPattern: `(?m)>\s*(.+)$`,
+			ClearFirst:    true,
+			ClearKeys:     "C-u",
+			NewlineKeys:   "S-Enter",
+			SubmitKeys:    "Enter",
+		},
+		{
+			Name:          "cursor",
+			DisplayName:   "Cursor",
+			DetectPattern: `(?i)cursor`,
+			PromptPattern: `(?m)│\s*(.+)$`,
+			StripPatterns: []string{"INSERT", "Add a follow-up"},
+			ClearFirst:    true,
+			ClearKeys:     "C-u",
+			NewlineKeys:   "S-Enter",
+			SubmitKeys:    "Enter",
+		},
+		{
+			Name:          "amp",
+			DisplayName:   "Amp",
+			DetectPattern: `(?i)(amp|sourcegraph)`,
+			PromptPattern: `(?m)>\s*(.+)$`,
+			ClearFirst:    true,
+			ClearKeys:     "C-u",
+			NewlineKeys:   "S-Enter",
+			SubmitKeys:    "Enter",
+		},
+		{
+			Name:          "aider",
+			DisplayName:   "Aider",
+			DetectPattern: `(?i)aider`,
+			PromptPattern: `(?m)>\s*(.+)$`,
+			ClearFirst:    true,
+			ClearKeys:     "C-u",
+			NewlineKeys:   "",
+			SubmitKeys:    "Enter",
+		},
+	}
+}
+
+// genericAgent returns a fallback agent with no detection or prompt extraction.
+// The user gets a blank editor and text is sent verbatim.
+func genericAgent() AgentConfig {
+	return AgentConfig{
+		Name:        "generic",
+		DisplayName: "Generic",
+		NewlineKeys: "",
+		SubmitKeys:  "Enter",
+	}
+}
+
+// resolveAgents merges built-in agent defaults with user-provided overrides
+// from config. Agents are matched by name (case-insensitive); user config
+// wins field-by-field over builtins.
+func resolveAgents(cfgAgents []appconfig.TmuxEditAgentCfg) []AgentConfig {
+	agents := builtinAgents()
+	for _, ca := range cfgAgents {
+		merged := false
+		for i, a := range agents {
+			if !strings.EqualFold(a.Name, ca.Name) {
+				continue
+			}
+			agents[i] = mergeAgentConfig(a, ca)
+			merged = true
+			break
+		}
+		if !merged {
+			agents = append(agents, agentFromConfig(ca))
+		}
+	}
+	return agents
+}
+
+// mergeAgentConfig overrides fields in base with non-zero values from cfg.
+func mergeAgentConfig(base AgentConfig, cfg appconfig.TmuxEditAgentCfg) AgentConfig {
+	if s := strings.TrimSpace(cfg.DisplayName); s != "" {
+		base.DisplayName = s
+	}
+	if s := strings.TrimSpace(cfg.DetectPattern); s != "" {
+		base.DetectPattern = s
+	}
+	if s := strings.TrimSpace(cfg.PromptPattern); s != "" {
+		base.PromptPattern = s
+	}
+	if len(cfg.StripPatterns) > 0 {
+		base.StripPatterns = cfg.StripPatterns
+	}
+	if cfg.ClearFirst != nil {
+		base.ClearFirst = *cfg.ClearFirst
+	}
+	if s := strings.TrimSpace(cfg.ClearKeys); s != "" {
+		base.ClearKeys = s
+	}
+	if s := strings.TrimSpace(cfg.NewlineKeys); s != "" {
+		base.NewlineKeys = s
+	}
+	if s := strings.TrimSpace(cfg.SubmitKeys); s != "" {
+		base.SubmitKeys = s
+	}
+	return base
+}
+
+// agentFromConfig creates a new AgentConfig from a user config entry.
+func agentFromConfig(cfg appconfig.TmuxEditAgentCfg) AgentConfig {
+	a := AgentConfig{
+		Name:          strings.TrimSpace(cfg.Name),
+		DisplayName:   strings.TrimSpace(cfg.DisplayName),
+		DetectPattern: strings.TrimSpace(cfg.DetectPattern),
+		PromptPattern: strings.TrimSpace(cfg.PromptPattern),
+		StripPatterns: cfg.StripPatterns,
+		ClearKeys:     strings.TrimSpace(cfg.ClearKeys),
+		NewlineKeys:   strings.TrimSpace(cfg.NewlineKeys),
+		SubmitKeys:    strings.TrimSpace(cfg.SubmitKeys),
+	}
+	if cfg.ClearFirst != nil {
+		a.ClearFirst = *cfg.ClearFirst
+	}
+	if a.DisplayName == "" {
+		a.DisplayName = a.Name
+	}
+	return a
+}
+
+// detectAgent tries each agent's DetectPattern against pane content.
+// First match wins. Returns genericAgent() if no agent matches.
+func detectAgent(paneContent string, agents []AgentConfig) AgentConfig {
+	for _, a := range agents {
+		if a.DetectPattern == "" {
+			continue
+		}
+		re, err := regexp.Compile(a.DetectPattern)
+		if err != nil {
+			continue
+		}
+		if re.MatchString(paneContent) {
+			return a
+		}
+	}
+	return genericAgent()
+}
+
+// findAgentByName returns the agent with the given name (case-insensitive),
+// falling back to genericAgent() if not found.
+func findAgentByName(name string, agents []AgentConfig) AgentConfig {
+	for _, a := range agents {
+		if strings.EqualFold(a.Name, name) {
+			return a
+		}
+	}
+	return genericAgent()
+}
+
+// extractPrompt uses the agent's PromptPattern to extract the current prompt
+// text from pane content. Returns empty string if no pattern or no match.
+func extractPrompt(paneContent string, agent AgentConfig) string {
+	if agent.PromptPattern == "" {
+		return ""
+	}
+	re, err := regexp.Compile(agent.PromptPattern)
+	if err != nil {
+		return ""
+	}
+	m := re.FindStringSubmatch(paneContent)
+	if len(m) < 2 {
+		return ""
+	}
+	text := m[1]
+	return stripNoise(text, agent.StripPatterns)
+}
+
+// stripNoise removes each of the agent's StripPatterns from text and trims
+// whitespace.
+func stripNoise(text string, patterns []string) string {
+	for _, p := range patterns {
+		text = strings.ReplaceAll(text, p, "")
+	}
+	return strings.TrimSpace(text)
+}