package calc

import (
	"context"
	"encoding/json"
	"strings"
	"testing"

	"gitea.stevedudenhoeffer.com/steve/majordomo/agent"
	"gitea.stevedudenhoeffer.com/steve/majordomo/llm"
	"gitea.stevedudenhoeffer.com/steve/majordomo/provider/fake"
)

func TestEval(t *testing.T) {
	tests := []struct {
		expr string
		want float64
	}{
		{"1+2", 3},
		{"2 * 3 + 4", 10},
		{"2 + 3 * 4", 14},
		{"(2 + 3) * 4", 20},
		{"10 / 4", 2.5},
		{"-3 + 5", 2},
		{"--3", 3},
		{"2^10", 1024},
		{"2^3^2", 512}, // right-associative
		{"-2^2", -4},   // unary binds looser than power
		{"7 % 3", 1},
		{"1.5e2 + 1", 151},
		{" ( 1 + 1 ) * ( 2 + 2 ) ", 8},
	}
	for _, tt := range tests {
		got, err := Eval(tt.expr)
		if err != nil {
			t.Errorf("Eval(%q): %v", tt.expr, err)
			continue
		}
		if got != tt.want {
			t.Errorf("Eval(%q) = %v, want %v", tt.expr, got, tt.want)
		}
	}
}

func TestEvalErrors(t *testing.T) {
	for _, expr := range []string{"", "1/0", "5 % 0", "2 +", "(1+2", "1 + abc", "1 2", "2^99999"} {
		if _, err := Eval(expr); err == nil {
			t.Errorf("Eval(%q) should error", expr)
		}
	}
}

// TestSkillInAgentLoop: an agent actually invokes calculate and answers
// from its result.
func TestSkillInAgentLoop(t *testing.T) {
	fp := fake.New("fp")
	fp.Enqueue("m",
		fake.ReplyWith(llm.Response{
			ToolCalls:    []llm.ToolCall{{ID: "c1", Name: "calculate", Arguments: json.RawMessage(`{"expression":"(2+3)*4"}`)}},
			FinishReason: llm.FinishToolCalls,
		}),
		fake.Reply("the answer is 20"),
	)
	m, _ := fp.Model("m")

	a := agent.New(m, "Math helper.", agent.WithSkill(New()))
	res, err := a.Run(context.Background(), "what is (2+3)*4?")
	if err != nil {
		t.Fatalf("Run: %v", err)
	}
	if res.Output != "the answer is 20" {
		t.Errorf("output = %q", res.Output)
	}
	result := res.Steps[0].Results[0]
	if result.IsError || !strings.Contains(result.Content, `"result":20`) {
		t.Errorf("tool result = %+v", result)
	}
}