package skill_test

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"
	"gitea.stevedudenhoeffer.com/steve/majordomo/skill"
)

// The skill package must satisfy the agent contract.
var _ agent.Skill = (*skill.Skill)(nil)

func TestSkillConstruction(t *testing.T) {
	tool := llm.Tool{Name: "t1"}
	sk := skill.New("research",
		skill.WithInstructions("Cite sources."),
		skill.WithTools(tool),
	)
	if sk.Name() != "research" || sk.Instructions() != "Cite sources." {
		t.Errorf("skill = %q / %q", sk.Name(), sk.Instructions())
	}
	if sk.Tools() == nil || len(sk.Tools().Tools()) != 1 {
		t.Errorf("tools = %+v", sk.Tools())
	}
	if sk.Tools().Name() != "research" {
		t.Errorf("toolbox name = %q, want skill name", sk.Tools().Name())
	}
}

func TestInstructionOnlySkill(t *testing.T) {
	sk := skill.New("tone", skill.WithInstructions("Be kind."))
	if sk.Tools() != nil {
		t.Error("instruction-only skill must have nil toolbox")
	}
}

// TestSkillsAttachToAnyAgent: the same skill instance layers onto multiple
// agents, on demand, extending prompt and toolset additively.
func TestSkillsAttachToAnyAgent(t *testing.T) {
	echo := llm.Tool{
		Name: "echo",
		Handler: func(_ context.Context, args json.RawMessage) (any, error) {
			return string(args), nil
		},
	}
	sk := skill.New("echoer",
		skill.WithInstructions("Echo when asked."),
		skill.WithTools(echo),
	)

	for _, base := range []string{"Agent one.", "Agent two."} {
		fp := fake.New("fp")
		fp.Enqueue("m", fake.Reply("done"))
		m, _ := fp.Model("m")

		a := agent.New(m, base)
		a.AddSkill(sk)
		if _, err := a.Run(context.Background(), "hi"); err != nil {
			t.Fatalf("Run: %v", err)
		}

		req := fp.Calls()[0].Request
		if !strings.HasPrefix(req.System, base) || !strings.Contains(req.System, "Echo when asked.") {
			t.Errorf("system = %q", req.System)
		}
		if len(req.Tools) != 1 || req.Tools[0].Name != "echo" {
			t.Errorf("tools = %+v", req.Tools)
		}
	}
}

// TestMultipleSkillsCompose: instructions append in order; toolsets merge.
func TestMultipleSkillsCompose(t *testing.T) {
	fp := fake.New("fp")
	fp.Enqueue("m", fake.Reply("ok"))
	m, _ := fp.Model("m")

	a := agent.New(m, "Base.",
		agent.WithSkill(skill.New("one", skill.WithInstructions("First."), skill.WithTools(llm.Tool{Name: "t1"}))),
		agent.WithSkill(skill.New("two", skill.WithInstructions("Second."), skill.WithTools(llm.Tool{Name: "t2"}))),
	)
	if _, err := a.Run(context.Background(), "go"); err != nil {
		t.Fatalf("Run: %v", err)
	}
	req := fp.Calls()[0].Request
	if req.System != "Base.\n\nFirst.\n\nSecond." {
		t.Errorf("system = %q", req.System)
	}
	if len(req.Tools) != 2 {
		t.Errorf("tools = %+v", req.Tools)
	}
}