package service

import (
	"testing"

	"github.com/Wei-Shaw/sub2api/internal/pkg/windsurf"
)

func TestShouldRunNLUFallback(t *testing.T) {
	// Force the fallback-enabled path; tests below cover the disabled path
	// via withNLUFallbackDisabledFn directly. The production env-Once design
	// makes t.Setenv ineffective once init has fired in a prior test.
	prev := nluFallbackDisabledFn
	nluFallbackDisabledFn = func() bool { return false }
	t.Cleanup(func() { nluFallbackDisabledFn = prev })

	tests := []struct {
		name string
		meta *windsurf.ModelMeta
		text string
		want bool
	}{
		{"empty text never runs", &windsurf.ModelMeta{Provider: "zhipu"}, "", false},
		{"explicit nlu always runs", &windsurf.ModelMeta{Provider: "zhipu"}, "Sure, I helped.", true},
		{"explicit override nlu wins over provider", &windsurf.ModelMeta{Provider: "anthropic", EmulationFlavor: "nlu"}, "any text", true},
		{"explicit tool_use never runs", &windsurf.ModelMeta{Provider: "anthropic"}, "function: edit_file {}", false},
		{"auto with no signal skips", &windsurf.ModelMeta{Provider: "openai"}, "Just a chat reply.", false},
		{"auto with signal runs", &windsurf.ModelMeta{Provider: "openai"}, `function: edit_file {"x":1}`, true},
		{"nil meta auto, signal", nil, "function: edit_file {}", true},
		{"nil meta auto, no signal", nil, "Hello world", false},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			if got := shouldRunNLUFallback(tc.meta, tc.text); got != tc.want {
				t.Fatalf("shouldRunNLUFallback = %v, want %v", got, tc.want)
			}
		})
	}
}

func TestShouldRunNLUFallback_DisabledByOverride(t *testing.T) {
	prev := nluFallbackDisabledFn
	nluFallbackDisabledFn = func() bool { return true }
	t.Cleanup(func() { nluFallbackDisabledFn = prev })

	got := shouldRunNLUFallback(&windsurf.ModelMeta{Provider: "zhipu"}, "function: x {}")
	if got {
		t.Fatal("expected disabled by override, got enabled")
	}
}

func TestAvailableToolNames(t *testing.T) {
	tests := []struct {
		name     string
		preamble string
		want     []string
	}{
		{"empty preamble", "", nil},
		{
			name: "function-call format with parens",
			preamble: `Tools:
- edit_file(path, content)
- read_file(path)
- run_command(cmd)`,
			want: []string{"edit_file", "read_file", "run_command"},
		},
		{
			name: "name: form",
			preamble: `tools:
  - name: foo
  - name: bar`,
			want: []string{"foo", "bar"},
		},
		{
			name: "deduplicates",
			preamble: `- edit_file(p)
- edit_file(p)`,
			want: []string{"edit_file"},
		},
		{
			name:     "ignores non-identifier lines",
			preamble: `Use the following tools:`,
			want:     nil,
		},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			got := availableToolNames(tc.preamble)
			if len(got) != len(tc.want) {
				t.Fatalf("expected %v, got %v", tc.want, got)
			}
			for i := range got {
				if got[i] != tc.want[i] {
					t.Fatalf("expected %v, got %v", tc.want, got)
				}
			}
		})
	}
}

func TestIsIdentifier(t *testing.T) {
	cases := []struct {
		s    string
		want bool
	}{
		{"", false},
		{"foo", true},
		{"foo_bar", true},
		{"FooBar", true},
		{"foo123", true},
		{"123foo", false},
		{"foo bar", false},
		{"foo-bar", false},
		{"foo.bar", false},
	}
	for _, tc := range cases {
		t.Run(tc.s, func(t *testing.T) {
			if got := isIdentifier(tc.s); got != tc.want {
				t.Fatalf("isIdentifier(%q) = %v, want %v", tc.s, got, tc.want)
			}
		})
	}
}