refactor(config): drop env-based config (except OPENAI_API_KEY)

- Switch to config-file-only; only OPENAI_API_KEY read from env.\n- llm: replace env autodetect with Config + NewFromConfig; add newOpenAI/newOllama.\n- lsp: NewServer now accepts injected llm.Client.\n- cli: remove env overrides; extend appConfig with provider-specific fields; build client from config + OPENAI_API_KEY.\n- docs: update README (config-only, defaults to OpenAI, minimal example); simplify flags table.\n- add config.json.example.\n- prompts: enforce ;text; (no spaces) and add ;;text; to remove entire line; tests added.

1 files changed, 131 insertions, 0 deletions

diff --git a/cmd/hexai/main.go b/cmd/hexai/main.go
new file mode 100644
index 0000000..7cd5296
--- /dev/null
+++ b/cmd/hexai/main.go
@@ -0,0 +1,131 @@
+package main
+
+import (
+    "encoding/json"
+    "flag"
+    "log"
+    "os"
+    "path/filepath"
+    "strings"
+
+    "hexai/internal"
+    "hexai/internal/logging"
+    "hexai/internal/lsp"
+    "hexai/internal/llm"
+)
+
+func main() {
+    var logPath string
+    var showVersion bool
+    flag.StringVar(&logPath, "log", "/tmp/hexai.log", "path to log file (optional)")
+    flag.BoolVar(&showVersion, "version", false, "print version and exit")
+    flag.Parse()
+
+    if showVersion {
+        log.Println(internal.Version)
+        return
+    }
+
+    // Configure logging (path flag only)
+    logger := log.New(os.Stderr, "hexai-lsp ", log.LstdFlags|log.Lmsgprefix)
+    if logPath != "" {
+        f, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+        if err != nil {
+            logger.Fatalf("failed to open log file: %v", err)
+        }
+        defer f.Close()
+        logger.SetOutput(f)
+    }
+    logging.Bind(logger)
+
+    // Load config file
+    cfg := loadConfig(logger)
+
+    // Normalize and apply logging config
+    cfg.ContextMode = strings.ToLower(strings.TrimSpace(cfg.ContextMode))
+    if cfg.LogPreviewLimit >= 0 {
+        logging.SetLogPreviewLimit(cfg.LogPreviewLimit)
+    }
+
+    // Build LLM client from config (only OPENAI_API_KEY may come from env)
+    var client llm.Client
+    {
+        llmCfg := llm.Config{
+            Provider:      cfg.Provider,
+            OpenAIBaseURL: cfg.OpenAIBaseURL,
+            OpenAIModel:   cfg.OpenAIModel,
+            OllamaBaseURL: cfg.OllamaBaseURL,
+            OllamaModel:   cfg.OllamaModel,
+        }
+        oaKey := os.Getenv("OPENAI_API_KEY")
+        if c, err := llm.NewFromConfig(llmCfg, oaKey); err != nil {
+            logging.Logf("lsp ", "llm disabled: %v", err)
+        } else {
+            client = c
+            logging.Logf("lsp ", "llm enabled provider=%s model=%s", c.Name(), c.DefaultModel())
+        }
+    }
+
+    server := lsp.NewServer(os.Stdin, os.Stdout, logger, logPath != "", cfg.MaxTokens, cfg.ContextMode, cfg.ContextWindowLines, cfg.MaxContextTokens, cfg.NoDiskIO, client)
+    if err := server.Run(); err != nil {
+        logger.Fatalf("server error: %v", err)
+    }
+}
+
+// appConfig holds user-configurable settings.
+type appConfig struct {
+    MaxTokens           int    `json:"max_tokens"`
+    ContextMode         string `json:"context_mode"`
+    ContextWindowLines  int    `json:"context_window_lines"`
+    MaxContextTokens    int    `json:"max_context_tokens"`
+    LogPreviewLimit     int    `json:"log_preview_limit"`
+    NoDiskIO            bool   `json:"no_disk_io"`
+    Provider            string `json:"provider"`
+    // Provider-specific options
+    OpenAIBaseURL       string `json:"openai_base_url"`
+    OpenAIModel         string `json:"openai_model"`
+    OllamaBaseURL       string `json:"ollama_base_url"`
+    OllamaModel         string `json:"ollama_model"`
+}
+
+func loadConfig(logger *log.Logger) appConfig {
+    // Defaults (mirror prior sensible values)
+    cfg := appConfig{
+        MaxTokens:          4000,
+        ContextMode:        "always-full",
+        ContextWindowLines: 120,
+        MaxContextTokens:   4000,
+        LogPreviewLimit:    100,
+        NoDiskIO:           true,
+    }
+    home, err := os.UserHomeDir()
+    if err != nil {
+        return cfg
+    }
+    path := filepath.Join(home, ".config", "hexai", "config.json")
+    f, err := os.Open(path)
+    if err != nil {
+        return cfg
+    }
+    defer f.Close()
+    dec := json.NewDecoder(f)
+    var fileCfg appConfig
+    if err := dec.Decode(&fileCfg); err != nil {
+        logger.Printf("invalid config file %s: %v", path, err)
+        return cfg
+    }
+    // Merge: file overrides defaults when provided
+    if fileCfg.MaxTokens > 0 { cfg.MaxTokens = fileCfg.MaxTokens }
+    if strings.TrimSpace(fileCfg.ContextMode) != "" { cfg.ContextMode = fileCfg.ContextMode }
+    if fileCfg.ContextWindowLines > 0 { cfg.ContextWindowLines = fileCfg.ContextWindowLines }
+    if fileCfg.MaxContextTokens > 0 { cfg.MaxContextTokens = fileCfg.MaxContextTokens }
+    if fileCfg.LogPreviewLimit >= 0 { cfg.LogPreviewLimit = fileCfg.LogPreviewLimit }
+    cfg.NoDiskIO = fileCfg.NoDiskIO
+    if strings.TrimSpace(fileCfg.Provider) != "" { cfg.Provider = fileCfg.Provider }
+    // Provider-specific options
+    if strings.TrimSpace(fileCfg.OpenAIBaseURL) != "" { cfg.OpenAIBaseURL = fileCfg.OpenAIBaseURL }
+    if strings.TrimSpace(fileCfg.OpenAIModel) != "" { cfg.OpenAIModel = fileCfg.OpenAIModel }
+    if strings.TrimSpace(fileCfg.OllamaBaseURL) != "" { cfg.OllamaBaseURL = fileCfg.OllamaBaseURL }
+    if strings.TrimSpace(fileCfg.OllamaModel) != "" { cfg.OllamaModel = fileCfg.OllamaModel }
+    return cfg
+}