package config

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

	"git.totmin.ru/en2zmax/addrkit/internal/domain/match"
)

func writeFile(t *testing.T, dir, name, content string) string {
	t.Helper()
	path := filepath.Join(dir, name)
	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
		t.Fatalf("write %s: %v", name, err)
	}
	return path
}

func baseConfig(promptFields string) string {
	return `{
      "addr": ":6171",
      "data_path": "registry.db",
      "llm": { "enabled": true, "url": "http://llm"` + promptFields + ` }
    }`
}

func TestLoadInlineSystemPrompt(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "config.json", baseConfig(`, "system_prompt": "INLINE PROMPT"`))

	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.LLM.SystemPrompt != "INLINE PROMPT" {
		t.Errorf("SystemPrompt = %q", cfg.LLM.SystemPrompt)
	}
}

func TestLoadSystemPromptFromFile(t *testing.T) {
	dir := t.TempDir()
	promptFile := writeFile(t, dir, "prompt.txt", "PROMPT FROM FILE\n")
	path := writeFile(t, dir, "config.json", baseConfig(`, "system_prompt_file": "`+promptFile+`"`))

	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.LLM.SystemPrompt != "PROMPT FROM FILE\n" {
		t.Errorf("SystemPrompt = %q", cfg.LLM.SystemPrompt)
	}
}

func TestLoadMissingSystemPromptFileFailsClosed(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "config.json", baseConfig(`, "system_prompt_file": "`+filepath.Join(dir, "nope.txt")+`"`))

	if _, err := Load(path); err == nil {
		t.Fatal("expected error for missing system_prompt_file")
	}
}

func TestDefaultsMatchMatcher(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "config.json", `{"addr": ":6171", "data_path": "x.db"}`)

	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	want := match.DefaultOptions()
	if cfg.Resolve.FuzzyThreshold != want.FuzzyThreshold ||
		cfg.Resolve.AmbiguityMargin != want.AmbiguityMargin ||
		cfg.Resolve.MaxCandidates != want.MaxCandidates {
		t.Fatalf("config defaults %+v do not match matcher defaults %+v", cfg.Resolve, want)
	}
}

func TestRejectsBadResolveRanges(t *testing.T) {
	dir := t.TempDir()
	cases := map[string]string{
		"threshold":  `{"addr":":6171","data_path":"x.db","resolve":{"fuzzy_threshold":0}}`,
		"margin":     `{"addr":":6171","data_path":"x.db","resolve":{"ambiguity_margin":2}}`,
		"candidates": `{"addr":":6171","data_path":"x.db","resolve":{"max_candidates":0}}`,
	}
	for name, body := range cases {
		path := writeFile(t, dir, name+".json", body)
		if _, err := Load(path); err == nil {
			t.Errorf("%s: expected validation error", name)
		}
	}
}

func TestCitiesAndDefaultCity(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "config.json", `{
      "addr": ":6171", "data_path": "x.db",
      "cities": [
        {"name": "Новосибирск", "aliases": ["нск", "новосибирская область"]},
        {"name": "Бердск"}
      ],
      "default_city": "Новосибирск"
    }`)
	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if len(cfg.Cities) != 2 || cfg.DefaultCity != "Новосибирск" {
		t.Fatalf("cities = %+v, default = %q", cfg.Cities, cfg.DefaultCity)
	}
}

func TestRejectsUnknownDefaultCity(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "config.json", `{
      "addr": ":6171", "data_path": "x.db",
      "cities": [{"name": "Бердск"}],
      "default_city": "Новосибирск"
    }`)
	if _, err := Load(path); err == nil {
		t.Fatal("expected error for default_city absent from cities")
	}
}

func TestLoadCitiesFile(t *testing.T) {
	dir := t.TempDir()
	path := writeFile(t, dir, "cities.json", `[
      {"name": "Новосибирск", "aliases": ["нск"]},
      {"name": "Бердск"}
    ]`)
	cities, err := LoadCitiesFile(path)
	if err != nil {
		t.Fatalf("LoadCitiesFile: %v", err)
	}
	if len(cities) != 2 || cities[0].Name != "Новосибирск" {
		t.Fatalf("cities = %+v", cities)
	}
}

func TestRejectsUnknownConfigFields(t *testing.T) {
	dir := t.TempDir()
	// "portal" was removed with the events module; silently ignoring it would
	// hide a stale deployment config.
	path := writeFile(t, dir, "config.json",
		`{"addr":":6171","data_path":"x.db","portal":{"url":"http://example"}}`)
	if _, err := Load(path); err == nil {
		t.Fatal("expected error for unknown config field")
	}
}