package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"monica-go-completion-backend/internal/completion"
)

func TestLoadConfigFileWithEnvOverride(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.json")
	content := `{
		"port": "8081",
		"requestTimeout": "3s",
		"enableRedis": false,
		"servers": [
			{
				"language": "go",
				"languageId": "go",
				"command": "gopls-from-file",
				"args": []
			}
		]
	}`
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatalf("write config file failed: %v", err)
	}

	t.Setenv("CONFIG_FILE", path)
	t.Setenv("PORT", "9090")
	t.Setenv("GO_LSP_COMMAND", "gopls-from-env")

	cfg, err := loadConfig()
	if err != nil {
		t.Fatalf("loadConfig() error = %v", err)
	}

	if cfg.Port != "9090" {
		t.Fatalf("expected env to override port, got %s", cfg.Port)
	}
	if cfg.RequestTimeout != 3*time.Second {
		t.Fatalf("expected requestTimeout=3s, got %s", cfg.RequestTimeout)
	}
	if cfg.EnableRedis {
		t.Fatal("expected enableRedis=false from config file")
	}

	goSpec, ok := findServer(cfg.Servers, "go")
	if !ok {
		t.Fatal("expected go server in config")
	}
	if goSpec.Command != "gopls-from-env" {
		t.Fatalf("expected go command overridden by env, got %s", goSpec.Command)
	}
}

func TestLoadConfigFileInvalidDuration(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.json")
	content := `{
		"requestTimeout": "not-a-duration"
	}`
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatalf("write config file failed: %v", err)
	}

	t.Setenv("CONFIG_FILE", path)

	_, err := loadConfig()
	if err == nil {
		t.Fatal("expected loadConfig() to fail")
	}
	if !strings.Contains(err.Error(), "requestTimeout") {
		t.Fatalf("expected requestTimeout parse error, got %v", err)
	}
}

func findServer(specs []completion.LanguageServerSpec, language string) (completion.LanguageServerSpec, bool) {
	target := strings.ToLower(strings.TrimSpace(language))
	for _, spec := range specs {
		if strings.ToLower(strings.TrimSpace(spec.Language)) == target {
			return spec, true
		}
	}
	return completion.LanguageServerSpec{}, false
}