package claudewatcher

import (
	"errors"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func collect(t *testing.T, body string) ([]Turn, int64, error) {
	t.Helper()
	var out []Turn
	end, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
		out = append(out, tr)
		return nil
	})
	return out, end, err
}

func TestParseStream_UserTurnStringContent(t *testing.T) {
	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":"hello world"}
`
	turns, end, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.Equal(t, "user", turns[0].Type)
	assert.Equal(t, "S", turns[0].SessionID)
	assert.Equal(t, "hello world", turns[0].Content)
	assert.False(t, turns[0].Skip)
	assert.Equal(t, int64(len(body)), end)
}

func TestParseStream_UserTurnContentBlocks(t *testing.T) {
	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"role":"user","content":[{"type":"text","text":"line 1"},{"type":"text","text":"line 2"}]}}
`
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.Equal(t, "line 1\nline 2", turns[0].Content)
}

func TestParseStream_AssistantToolUse(t *testing.T) {
	body := `{"type":"assistant","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"content":[{"type":"text","text":"calling now"},{"type":"tool_use","name":"Edit","input":{}}]}}
`
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.Equal(t, "Edit", turns[0].ToolName)
	assert.Contains(t, turns[0].Content, "calling now")
	assert.Contains(t, turns[0].Content, "[tool_use:Edit]")
}

func TestParseStream_AssistantToolResult(t *testing.T) {
	body := `{"type":"user","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","message":{"content":[{"type":"tool_result","content":"output of cmd"}]}}
`
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.Contains(t, turns[0].Content, "[tool_result] output of cmd")
}

func TestParseStream_SkipsBookkeepingTypes(t *testing.T) {
	body := strings.Join([]string{
		`{"type":"queue-operation","sessionId":"S","content":"x"}`,
		`{"type":"last-prompt","sessionId":"S","lastPrompt":"y"}`,
		`{"type":"permission-mode","sessionId":"S","permissionMode":"auto"}`,
		`{"type":"ai-title","sessionId":"S","aiTitle":"My session"}`,
		`{"type":"file-history-snapshot","messageId":"abc"}`,
	}, "\n") + "\n"
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 5)
	for _, tr := range turns {
		assert.True(t, tr.Skip, "expected Skip=true for %q", tr.Type)
	}
}

func TestParseStream_UnknownTypeIsSkip(t *testing.T) {
	body := `{"type":"future-thing","sessionId":"S"}` + "\n"
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.True(t, turns[0].Skip)
}

func TestParseStream_MalformedLineIsSkippedNotFatal(t *testing.T) {
	body := strings.Join([]string{
		`{"type":"user","sessionId":"S","message":"first"}`,
		`{not valid json`,
		`{"type":"user","sessionId":"S","message":"third"}`,
	}, "\n") + "\n"
	var warnings int
	var turns []Turn
	_, err := ParseStream(strings.NewReader(body), 0, func(format string, args ...any) {
		warnings++
	}, func(tr Turn) error {
		turns = append(turns, tr)
		return nil
	})
	require.NoError(t, err)
	require.Len(t, turns, 2, "first + third should make it through")
	assert.Equal(t, 1, warnings)
}

func TestParseStream_EmitErrStopHaltsCleanly(t *testing.T) {
	body := strings.Join([]string{
		`{"type":"user","sessionId":"S","message":"a"}`,
		`{"type":"user","sessionId":"S","message":"b"}`,
		`{"type":"user","sessionId":"S","message":"c"}`,
	}, "\n") + "\n"
	count := 0
	end, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
		count++
		if count == 2 {
			return ErrStop
		}
		return nil
	})
	require.NoError(t, err)
	assert.Equal(t, 2, count)
	assert.Greater(t, end, int64(0))
}

func TestParseStream_EmitOtherErrorPropagates(t *testing.T) {
	body := `{"type":"user","sessionId":"S","message":"a"}` + "\n"
	want := errors.New("boom")
	_, err := ParseStream(strings.NewReader(body), 0, nil, func(tr Turn) error {
		return want
	})
	require.Error(t, err)
	assert.Contains(t, err.Error(), "boom")
}

func TestParseStream_AttachmentHookEvent(t *testing.T) {
	body := `{"type":"attachment","sessionId":"S","timestamp":"2026-05-25T07:00:00Z","attachment":{"type":"hook_success","hookName":"SessionStart:startup","hookEvent":"SessionStart","content":"hook body"}}
`
	turns, _, err := collect(t, body)
	require.NoError(t, err)
	require.Len(t, turns, 1)
	assert.Equal(t, "hook body", turns[0].Content)
}

func TestParseStream_OffsetAdvances(t *testing.T) {
	body := `{"type":"user","sessionId":"S","message":"a"}` + "\n" +
		`{"type":"user","sessionId":"S","message":"b"}` + "\n"
	var offsets []int64
	_, err := ParseStream(strings.NewReader(body), 100, nil, func(tr Turn) error {
		offsets = append(offsets, tr.OffsetAfter)
		return nil
	})
	require.NoError(t, err)
	require.Len(t, offsets, 2)
	assert.Greater(t, offsets[0], int64(100))
	assert.Greater(t, offsets[1], offsets[0])
}