refactor tmuxedit to Agent interface with cursor/claude/config implementations

Replace monolithic AgentConfig struct with an Agent interface backed by
baseAgent defaults and separate implementations for cursor (box-drawing
extraction, bulk backspace clearing) and claude (section-scoped extraction
with continuation lines, vim clearing). Simple agents (amp, aider) and
user-defined agents use configAgent with baseAgent defaults.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 134 insertions, 0 deletions

diff --git a/internal/tmuxedit/config_agent.go b/internal/tmuxedit/config_agent.go
new file mode 100644
index 0000000..2773025
--- /dev/null
+++ b/internal/tmuxedit/config_agent.go
@@ -0,0 +1,134 @@
+package tmuxedit
+
+import (
+	"strings"
+
+	"codeberg.org/snonux/hexai/internal/appconfig"
+)
+
+// configAgent uses baseAgent defaults for all operations. It serves
+// user-defined agents from TOML config and simple built-ins (amp, aider)
+// that don't need specialized extraction or clearing logic.
+type configAgent struct{ baseAgent }
+
+// builtinAgents returns the default set of agent implementations. Order
+// matters: agents with distinctive UI elements (box-drawing, etc.) are
+// checked first to avoid false positives from model names like "Claude
+// 4.5 Sonnet" appearing in other agents' panes.
+func builtinAgents() []Agent {
+	return []Agent{
+		newCursorAgent(),
+		newClaudeAgent(),
+		&configAgent{baseAgent{
+			name:          "amp",
+			displayName:   "Amp",
+			detectPattern: `(?i)(amp|sourcegraph)`,
+			promptPat:     `(?m)>\s*(.+)$`,
+			clearFirst:    true,
+			clearKeys:     "C-u",
+			newlineKeys:   "S-Enter",
+			submitKeys:    "Enter",
+		}},
+		&configAgent{baseAgent{
+			name:          "aider",
+			displayName:   "Aider",
+			detectPattern: `(?i)aider`,
+			promptPat:     `(?m)>\s*(.+)$`,
+			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() Agent {
+	return &configAgent{baseAgent{
+		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. The Configurable interface provides
+// access to baseAgent fields for merging.
+func resolveAgents(cfgAgents []appconfig.TmuxEditAgentCfg) []Agent {
+	agents := builtinAgents()
+	for _, ca := range cfgAgents {
+		merged := false
+		for i, a := range agents {
+			if !strings.EqualFold(a.Name(), ca.Name) {
+				continue
+			}
+			if c, ok := a.(Configurable); ok {
+				mergeAgentConfig(c.Base(), ca)
+			}
+			merged = true
+			_ = i // index not needed; we modify through the pointer
+			break
+		}
+		if !merged {
+			agents = append(agents, agentFromConfig(ca))
+		}
+	}
+	return agents
+}
+
+// mergeAgentConfig overrides fields in base with non-zero values from cfg.
+// It modifies the baseAgent in place via pointer.
+func mergeAgentConfig(base *baseAgent, cfg appconfig.TmuxEditAgentCfg) {
+	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.SectionPattern); s != "" {
+		base.sectionPat = s
+	}
+	if s := strings.TrimSpace(cfg.PromptPattern); s != "" {
+		base.promptPat = 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
+	}
+}
+
+// agentFromConfig creates a new configAgent from a user config entry.
+func agentFromConfig(cfg appconfig.TmuxEditAgentCfg) Agent {
+	b := baseAgent{
+		name:          strings.TrimSpace(cfg.Name),
+		displayName:   strings.TrimSpace(cfg.DisplayName),
+		detectPattern: strings.TrimSpace(cfg.DetectPattern),
+		sectionPat:    strings.TrimSpace(cfg.SectionPattern),
+		promptPat:     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 {
+		b.clearFirst = *cfg.ClearFirst
+	}
+	if b.displayName == "" {
+		b.displayName = b.name
+	}
+	return &configAgent{b}
+}