package scaffold

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

	"nub/internal/config"
)

func TestInit_CreatesConfigAndAgentsFile(t *testing.T) {
	dir := t.TempDir()

	res, err := Init(dir)
	if err != nil {
		t.Fatal(err)
	}
	if !res.ConfigCreated {
		t.Error("expected config.toml to be created")
	}
	if !res.AgentsCreated {
		t.Error("expected AGENTS.md to be created")
	}

	if _, err := os.Stat(filepath.Join(dir, ".nub", "config.toml")); err != nil {
		t.Errorf(".nub/config.toml missing: %v", err)
	}
	if _, err := os.Stat(filepath.Join(dir, "AGENTS.md")); err != nil {
		t.Errorf("AGENTS.md missing: %v", err)
	}

	content, err := os.ReadFile(filepath.Join(dir, ".nub", "config.toml"))
	if err != nil {
		t.Fatal(err)
	}
	if !contains(string(content), "[permissions]") {
		t.Error("expected the example config to include a [permissions] section")
	}
	if !contains(string(content), "version = 1") {
		t.Error("expected the example config to declare version = 1")
	}
}

func TestInit_DoesNotOverwriteExistingFiles(t *testing.T) {
	dir := t.TempDir()
	if err := os.MkdirAll(filepath.Join(dir, ".nub"), 0o700); err != nil {
		t.Fatal(err)
	}
	customConfig := "version = 1\n# my custom config, do not touch\n"
	if err := os.WriteFile(filepath.Join(dir, ".nub", "config.toml"), []byte(customConfig), 0o600); err != nil {
		t.Fatal(err)
	}
	customAgents := "# my custom AGENTS.md\n"
	if err := os.WriteFile(filepath.Join(dir, "AGENTS.md"), []byte(customAgents), 0o644); err != nil {
		t.Fatal(err)
	}

	res, err := Init(dir)
	if err != nil {
		t.Fatal(err)
	}
	if res.ConfigCreated {
		t.Error("expected an existing config.toml not to be reported as created")
	}
	if res.AgentsCreated {
		t.Error("expected an existing AGENTS.md not to be reported as created")
	}

	gotConfig, _ := os.ReadFile(filepath.Join(dir, ".nub", "config.toml"))
	if string(gotConfig) != customConfig {
		t.Error("existing config.toml must not be overwritten")
	}
	gotAgents, _ := os.ReadFile(filepath.Join(dir, "AGENTS.md"))
	if string(gotAgents) != customAgents {
		t.Error("existing AGENTS.md must not be overwritten")
	}
}

func TestInit_GeneratedConfigParsesAndRoundTripsPermissions(t *testing.T) {
	dir := t.TempDir()
	t.Setenv("NUB_MODEL", "")
	t.Setenv("NUB_BASE_URL", "")
	t.Setenv("NUB_API_KEY", "")
	t.Setenv("OPENAI_API_KEY", "dummy-for-this-test")

	if _, err := Init(dir); err != nil {
		t.Fatal(err)
	}

	cfg, err := config.Load(dir)
	if err != nil {
		t.Fatalf("generated config.toml failed to parse: %v", err)
	}
	if cfg.Permissions.Write != "ask" || cfg.Permissions.Edit != "ask" || cfg.Permissions.Bash != "ask" {
		t.Errorf("expected write/edit/bash = ask in the generated config, got %+v", cfg.Permissions)
	}
	if len(cfg.Permissions.DenyPaths) == 0 {
		t.Error("expected deny_paths to be populated in the generated config")
	}
}

func TestInit_SetsUpGitExclude(t *testing.T) {
	dir := t.TempDir()
	if err := os.MkdirAll(filepath.Join(dir, ".git", "info"), 0o755); err != nil {
		t.Fatal(err)
	}

	if _, err := Init(dir); err != nil {
		t.Fatal(err)
	}

	excludeContent, err := os.ReadFile(filepath.Join(dir, ".git", "info", "exclude"))
	if err != nil {
		t.Fatal(err)
	}
	if !contains(string(excludeContent), ".nub/") {
		t.Error("expected .nub/ to be added to .git/info/exclude")
	}
}

func contains(s, sub string) bool {
	return len(s) >= len(sub) && (func() bool {
		for i := 0; i+len(sub) <= len(s); i++ {
			if s[i:i+len(sub)] == sub {
				return true
			}
		}
		return false
	})()
}