// internal/skills/trainer/handlers_test.go
package trainer_test

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

	iexec "github.com/mathiasbq/supervisor/internal/exec"
	"github.com/mathiasbq/supervisor/internal/session"
	"github.com/mathiasbq/supervisor/internal/skills/trainer"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestTrainerToolRegistered(t *testing.T) {
	sk := trainer.New(trainer.Config{ReaderPrompt: "r", WriterPrompt: "w"})
	names := make([]string, 0)
	for _, tool := range sk.Tools() {
		names = append(names, tool.Name)
	}
	assert.Contains(t, names, "trainer")
}

func TestTrainerRequiresSessionID(t *testing.T) {
	sk := trainer.New(trainer.Config{ReaderPrompt: "r", WriterPrompt: "w"})
	_, err := sk.Handle(context.Background(), "trainer", json.RawMessage(`{}`))
	assert.ErrorContains(t, err, "session_id")
}

func TestTrainerCallsReaderThenWriter(t *testing.T) {
	sessDir := t.TempDir()
	require.NoError(t, session.Append(sessDir, "sess-1", session.Entry{
		SessionID: "sess-1", Skill: "tdd", Phase: "red", FinalStatus: "pass",
		Message: "wrote failing test", FilePath: "internal/foo/foo_test.go",
	}))

	callCount := 0
	var readerTask, writerTask string

	fakeFn := func(_ context.Context, req iexec.Request) (iexec.Result, error) {
		callCount++
		if callCount == 1 {
			// reader call
			readerTask = req.TaskPrompt
			return iexec.Result{
				Status: "pass", Phase: "trainer", Skill: "trainer",
				RunnerOutput: `[{"type":"sft","moment":"first-pass clean TDD","score":4}]`,
				Verified: true, ModelUsed: "self", Message: "1 sft candidate found",
			}, nil
		}
		// writer call
		writerTask = req.TaskPrompt
		return iexec.Result{
			Status: "pass", Phase: "trainer", Skill: "trainer",
			FilePath: sessDir + "/training-data/sft/sess-1.jsonl",
			Verified: true, ModelUsed: "self", Message: "1 sft pair written",
		}, nil
	}

	sk := trainer.New(trainer.Config{
		ReaderPrompt: "reader rules",
		WriterPrompt: "writer rules",
		ExecutorFn:   fakeFn,
		SessionsDir:  sessDir,
		BrainDir:     t.TempDir(),
	})
	out, err := sk.Handle(context.Background(), "trainer", json.RawMessage(`{"session_id":"sess-1"}`))
	require.NoError(t, err)

	assert.Equal(t, 2, callCount, "executor must be called exactly twice: reader then writer")
	assert.Contains(t, readerTask, "role: reader")
	assert.Contains(t, readerTask, "sess-1")
	assert.Contains(t, readerTask, "wrote failing test") // session history in reader prompt
	assert.Contains(t, writerTask, "role: writer")
	assert.Contains(t, writerTask, "sft candidate") // reader output passed to writer

	var result iexec.Result
	require.NoError(t, json.Unmarshal(out, &result))
	assert.Equal(t, "trainer", result.Phase)
	assert.Equal(t, "pass", result.Status)
}