package chain

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/tcs-iptv/tcs/internal/model"
)

func newIssued(t *testing.T) *MemoryChain {
	t.Helper()
	c := NewMemoryChain()
	_, err := c.IssueMA(RoleRegulator, IssueRequest{
		MACode:        "(京)网微剧审字(2025)第123号",
		ContentTwinID: "ctid-001",
		MerkleRoot:    "merkle-root-1",
		FileHash:      "filehash-1",
		Content:       model.Content{Title: "示例剧集", EpisodeCount: 24},
	})
	require.NoError(t, err)
	return c
}

func TestIssueMA_OnlyRegulator(t *testing.T) {
	c := NewMemoryChain()
	_, err := c.IssueMA(RoleCP, IssueRequest{MACode: "MA-1", ContentTwinID: "ct-1", FileHash: "h1"})
	assert.ErrorIs(t, err, ErrPermissionDenied)

	_, err = c.IssueMA(RoleReviewer, IssueRequest{MACode: "MA-1", ContentTwinID: "ct-1", FileHash: "h1"})
	assert.ErrorIs(t, err, ErrPermissionDenied)

	_, err = c.IssueMA(RoleRegulator, IssueRequest{MACode: "MA-1", ContentTwinID: "ct-1", FileHash: "h1"})
	assert.NoError(t, err)
}

func TestIssueMA_NoReissue(t *testing.T) {
	c := newIssued(t)
	// 同 MA 码重复签发被拒（1:1 不可解绑/不可覆盖）
	_, err := c.IssueMA(RoleRegulator, IssueRequest{
		MACode: "(京)网微剧审字(2025)第123号", ContentTwinID: "ctid-001", FileHash: "other",
	})
	assert.ErrorIs(t, err, ErrMAAlreadyIssued)
}

func TestIssueMA_DuplicateHashRejected(t *testing.T) {
	c := newIssued(t)
	// 换壳重发：不同 MA 码但相同内容哈希 → 拒绝
	_, err := c.IssueMA(RoleRegulator, IssueRequest{
		MACode: "(沪)网微剧审字(2025)第999号", ContentTwinID: "ctid-002", FileHash: "filehash-1",
	})
	assert.ErrorIs(t, err, ErrHashExists)
}

func TestVerifyHash_MatchAndMismatch(t *testing.T) {
	c := newIssued(t)

	res, err := c.VerifyHash("(京)网微剧审字(2025)第123号", "filehash-1")
	require.NoError(t, err)
	assert.True(t, res.Match)
	assert.True(t, res.Valid)

	res, err = c.VerifyHash("(京)网微剧审字(2025)第123号", "tampered-hash")
	require.NoError(t, err)
	assert.False(t, res.Match)
	assert.Equal(t, "filehash-1", res.BoundHash)
}

func TestVerifyHash_UnknownMA(t *testing.T) {
	c := NewMemoryChain()
	_, err := c.VerifyHash("no-such-ma", "h")
	assert.ErrorIs(t, err, ErrMANotIssued)
}

func TestRegisterMapping_RequiresIssuedMA(t *testing.T) {
	c := NewMemoryChain()
	// CTID 未签发 → 拒绝
	_, err := c.RegisterMapping(RoleOperator, model.Mapping{
		ContentTwinID: "ctid-x", Party: model.PartyOperator, PartyID: "OP-1",
	})
	assert.ErrorIs(t, err, ErrMANotIssued)

	c = newIssued(t)
	_, err = c.RegisterMapping(RoleOperator, model.Mapping{
		ContentTwinID: "ctid-001", Party: model.PartyOperator,
		PartyID: "CT-IPTV-008923", CDNEndpoint: "cdn://ct-gd/iptv/vod/008923",
	})
	assert.NoError(t, err)

	res, err := c.QueryMappings("(京)网微剧审字(2025)第123号")
	require.NoError(t, err)
	assert.Len(t, res.Mappings, 1)
	assert.Equal(t, []string{"cdn://ct-gd/iptv/vod/008923"}, res.CDNEndpoints)
}

func TestTranscodedBinding_ParentChild(t *testing.T) {
	c := newIssued(t)
	_, err := c.RegisterHashBinding(RoleReviewer, model.HashBinding{
		ContentTwinID: "ctid-001",
		HashType:      model.HashTranscoded,
		HashValue:     "transcoded-h265-4k",
		ParentHash:    "filehash-1",
		Version:       "v1.0-h265",
	})
	require.NoError(t, err)

	// 转码版哈希也能验真通过
	res, err := c.VerifyHash("(京)网微剧审字(2025)第123号", "transcoded-h265-4k")
	require.NoError(t, err)
	assert.True(t, res.Match)
}

func TestRevoke_OnlyRegulator(t *testing.T) {
	c := newIssued(t)
	_, _ = c.RegisterMapping(RoleOperator, model.Mapping{
		ContentTwinID: "ctid-001", Party: model.PartyOperator,
		PartyID: "OP-1", CDNEndpoint: "cdn://x/y/z",
	})

	_, err := c.Revoke(RoleOperator, "(京)网微剧审字(2025)第123号", "试图越权")
	assert.ErrorIs(t, err, ErrPermissionDenied)

	res, err := c.Revoke(RoleRegulator, "(京)网微剧审字(2025)第123号", "违规")
	require.NoError(t, err)
	assert.Contains(t, res.CDNEndpoints, "cdn://x/y/z")

	ct, _ := c.QueryContent("(京)网微剧审字(2025)第123号")
	assert.Equal(t, model.StatusRevoked, ct.Status)
}

func TestRecordVersionChange(t *testing.T) {
	c := newIssued(t)
	_, err := c.RecordVersionChange(model.VersionChange{
		ContentTwinID: "ctid-001", Version: "v2.0",
		ChangeReason: "片尾字幕修正", PrevHash: "filehash-1", NewHash: "filehash-2",
		ReauditRequired: true, AffectedEpisode: 24,
	})
	assert.NoError(t, err)
}

func TestHashExists(t *testing.T) {
	c := newIssued(t)
	ma, ok := c.HashExists("filehash-1")
	assert.True(t, ok)
	assert.Equal(t, "(京)网微剧审字(2025)第123号", ma)

	_, ok = c.HashExists("unknown")
	assert.False(t, ok)
}