package matrix

import "testing"

func TestIsWeakModel(t *testing.T) {
	cases := []struct {
		model string
		weak  bool
	}{
		// :free suffix → weak
		{"openai/gpt-4o:free", true},
		{"meta-llama/llama-3-8b:free", true},
		// :free/ infix (routing-prefixed names)
		{"openrouter:free/anthropic/claude-3.5-sonnet", true},
		// Local last-resort rungs
		{"qwen3.5:latest", true},
		{"qwen3:latest", true},
		// Strong by default
		{"x-ai/grok-4.1-fast", false},
		{"opencode/claude-opus-4-7", false},
		{"openai/gpt-5", false},
		{"qwen3-coder:480b", false}, // not the :latest tag
		{"", false},
	}
	for _, c := range cases {
		got := IsWeakModel(c.model)
		if got != c.weak {
			t.Errorf("IsWeakModel(%q): want %v, got %v", c.model, c.weak, got)
		}
	}
}

func TestMaybeDowngrade_TruthTable(t *testing.T) {
	cases := []struct {
		name string
		in   DowngradeInput
		want DowngradeDecision
	}{
		{
			name: "downgrade fires: lakehouse mode + strong model + no force",
			in:   DowngradeInput{Mode: ModeCodeReviewLakehouse, Model: "x-ai/grok-4.1-fast"},
			want: DowngradeDecision{
				Mode:           ModeCodeReviewIsolation,
				DowngradedFrom: ModeCodeReviewLakehouse,
			},
		},
		{
			name: "no downgrade: forced mode bypasses gate",
			in:   DowngradeInput{Mode: ModeCodeReviewLakehouse, Model: "x-ai/grok-4.1-fast", ForcedMode: true},
			want: DowngradeDecision{Mode: ModeCodeReviewLakehouse},
		},
		{
			name: "no downgrade: env override bypasses gate",
			in:   DowngradeInput{Mode: ModeCodeReviewLakehouse, Model: "x-ai/grok-4.1-fast", ForceFullOverride: true},
			want: DowngradeDecision{Mode: ModeCodeReviewLakehouse},
		},
		{
			name: "no downgrade: weak model keeps lakehouse",
			in:   DowngradeInput{Mode: ModeCodeReviewLakehouse, Model: "openai/gpt-4o:free"},
			want: DowngradeDecision{Mode: ModeCodeReviewLakehouse},
		},
		{
			name: "no downgrade: non-lakehouse mode (gate not applicable)",
			in:   DowngradeInput{Mode: "codereview_isolation", Model: "x-ai/grok-4.1-fast"},
			want: DowngradeDecision{Mode: "codereview_isolation"},
		},
	}
	for _, c := range cases {
		got := MaybeDowngrade(c.in)
		if got.Mode != c.want.Mode {
			t.Errorf("%s: Mode want %q, got %q", c.name, c.want.Mode, got.Mode)
		}
		if got.DowngradedFrom != c.want.DowngradedFrom {
			t.Errorf("%s: DowngradedFrom want %q, got %q", c.name, c.want.DowngradedFrom, got.DowngradedFrom)
		}
		if got.Reason == "" {
			t.Errorf("%s: Reason should be non-empty", c.name)
		}
	}
}

// TestMaybeDowngrade_ForcedTrumpsOthers verifies precedence: when
// multiple bypass conditions hit, ForcedMode wins (explicit caller
// intent always overrides). Caught a subtle ordering bug in the
// original Rust code where this was tested only by happy path.
func TestMaybeDowngrade_ForcedTrumpsOthers(t *testing.T) {
	in := DowngradeInput{
		Mode:              ModeCodeReviewLakehouse,
		Model:             "qwen3.5:latest", // weak — would otherwise hit weak-bypass
		ForcedMode:        true,
		ForceFullOverride: true,
	}
	got := MaybeDowngrade(in)
	if got.Mode != ModeCodeReviewLakehouse {
		t.Errorf("forced mode should keep mode: got %q", got.Mode)
	}
	if got.DowngradedFrom != "" {
		t.Errorf("no downgrade expected; got DowngradedFrom=%q", got.DowngradedFrom)
	}
}