package rules

import (
	"testing"

	"git.yeij.top/AskaEth/Scoreboard/server/internal/domain"
)

func testSnapshot(t *testing.T, profiles []Profile, events []EventInfo) *Snapshot {
	t.Helper()
	pack := RulePack{
		Format:        FormatName,
		FormatVersion: FormatVersion,
		Meta:          Meta{Code: "demo", Name: "当前规则"},
		Standings:     Standings{IndividualToTeamWeight: 1, TieBreak: DefaultTieBreak},
		Profiles:      profiles,
	}
	canonical := pack.Canonical()
	return &Snapshot{Pack: &canonical, Events: events}
}

func currentSnapshot(t *testing.T) *Snapshot {
	t.Helper()
	return testSnapshot(t,
		[]Profile{
			{
				Code: "individual_top6", Name: "个人项目前六名", AwardRanks: 6, TieMode: domain.TieSkip,
				Rules: []Rule{{1, 10}, {2, 8}, {3, 6}, {4, 3}, {5, 2}, {6, 1}},
			},
			{
				Code: "team_top6", Name: "团体项目前六名", AwardRanks: 2, TieMode: domain.TieSkip,
				Rules: []Rule{{1, 15}, {2, 10}},
			},
		},
		[]EventInfo{
			{ID: 1, Code: "EVT_IND", Name: "个人示例", EventType: domain.EventTypeIndividual, ResultType: domain.ResultTypeTime,
				Scored: true, Multiplier: 1,
				Channels: []Channel{{Scope: domain.ScopeAthlete, Basis: domain.BasisResult, Profile: "individual_top6"}}},
			{ID: 2, Code: "EVT_TEAM", Name: "团体示例", EventType: domain.EventTypeTeam, ResultType: domain.ResultTypeNone,
				Scored: true, Multiplier: 1,
				Channels: []Channel{{Scope: domain.ScopeTeam, Basis: domain.BasisManual, Profile: "team_top6"}}},
			{ID: 3, Code: "EVT_MATCH", Name: "对抗示例", EventType: domain.EventTypeMatch, ResultType: domain.ResultTypeNone,
				Scored: true, Multiplier: 1,
				Channels: []Channel{{Scope: domain.ScopeTeam, Basis: domain.BasisManual, Profile: "team_top6"}}},
		})
}

const nextPackYAML = `format: scoreboard-rules
formatVersion: 1
meta: { code: demo, name: 目标规则包 }
standings:
  individualToTeamWeight: 2
  tieBreak: [points, gold, silver, bronze, teamCode]
  medalCountsTeamEvents: true
  showIndividualBoard: true
  showIndividualMedals: true
profiles:
  - code: individual_top6
    name: 个人项目前六名
    awardRanks: 6
    tieMode: skip
    rules:
      - { rank: 1, points: 12 }
      - { rank: 2, points: 9 }
      - { rank: 3, points: 7 }
      - { rank: 4, points: 4 }
      - { rank: 5, points: 3 }
      - { rank: 6, points: 2 }
  - code: special_top3
    name: 特别项目前三名
    awardRanks: 3
    tieMode: higher
    rules:
      - { rank: 1, points: 5 }
      - { rank: 2, points: 3 }
      - { rank: 3, points: 1 }
channelTemplates:
  - match: { eventType: individual }
    channels:
      - { scope: athlete, basis: result, profile: individual_top6 }
  - match: { eventType: team }
    channels:
      - { scope: team, basis: manual, profile: special_top3 }
eventOverrides:
  - eventCode: EVT_MATCH
    channels: []
  - eventCode: EVT_GHOST
    channels:
      - { scope: team, basis: manual, profile: special_top3 }
`

func TestDiffDetectsAddModifyRemove(t *testing.T) {
	cur := currentSnapshot(t)
	next, err := Parse([]byte(nextPackYAML))
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}

	cs, err := Diff(cur, next)
	if err != nil {
		t.Fatalf("Diff: %v", err)
	}
	if cs.Empty() {
		t.Fatal("差异不应为空")
	}

	kinds := map[string]ChangeKind{}
	for _, p := range cs.Profiles {
		kinds[p.Code] = p.Kind
	}
	if kinds["individual_top6"] != ChangeModified {
		t.Errorf("individual_top6 应为 modified，实际 %q", kinds["individual_top6"])
	}
	if kinds["team_top6"] != ChangeRemoved {
		t.Errorf("team_top6 应为 removed，实际 %q", kinds["team_top6"])
	}
	if kinds["special_top3"] != ChangeAdded {
		t.Errorf("special_top3 应为 added，实际 %q", kinds["special_top3"])
	}
	for _, p := range cs.Profiles {
		if p.Code == "individual_top6" && len(p.Fields) == 0 {
			t.Error("修改的模板应列出变化字段")
		}
		if p.Code == "special_top3" && (p.Before != nil || p.After == nil) {
			t.Error("新增模板的 Before 应为空、After 应有值")
		}
	}

	channels := map[string]ChannelChange{}
	for _, c := range cs.Channels {
		channels[c.EventCode] = c
	}
	if c, ok := channels["EVT_TEAM"]; !ok || c.Kind != ChangeModified {
		t.Errorf("EVT_TEAM 通道应变为 special_top3: %+v", c)
	}
	if c, ok := channels["EVT_MATCH"]; !ok || c.Kind != ChangeRemoved || len(c.After) != 0 {
		t.Errorf("EVT_MATCH 通道应被清空: %+v", c)
	}
	if _, ok := channels["EVT_IND"]; ok {
		t.Error("EVT_IND 通道未变化，不应出现在差异里")
	}
	if len(cs.UnknownEvents) != 1 || cs.UnknownEvents[0] != "EVT_GHOST" {
		t.Errorf("未知项目识别错误: %v", cs.UnknownEvents)
	}

	if len(cs.Settings) != 1 || cs.Settings[0].Key != settingIndividualToTeamWeight {
		t.Errorf("设置差异错误: %+v", cs.Settings)
	}
	if cs.Settings[0].Before != "1" || cs.Settings[0].After != "2" {
		t.Errorf("权重差异值错误: %+v", cs.Settings[0])
	}
}

func TestDiffIdenticalIsEmpty(t *testing.T) {
	cur := currentSnapshot(t)
	same, err := Diff(cur, cur.Pack)
	if err != nil {
		t.Fatalf("Diff: %v", err)
	}
	if !same.Empty() {
		t.Errorf("同一份规则包不应产生差异: %+v", same)
	}
}

func TestDiffRejectsInvalidPack(t *testing.T) {
	cur := currentSnapshot(t)
	bad, err := Parse([]byte(minimalPackYAML))
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	bad.FormatVersion = 99
	if _, err := Diff(cur, bad); err == nil {
		t.Fatal("非法规则包应报错")
	}
}

func TestResolveTargetsPrecedence(t *testing.T) {
	cur := currentSnapshot(t)
	next, err := Parse([]byte(nextPackYAML))
	if err != nil {
		t.Fatalf("Parse: %v", err)
	}
	targets, unknown, err := resolveTargets(cur, next)
	if err != nil {
		t.Fatalf("resolveTargets: %v", err)
	}

	if got := targets["EVT_IND"]; len(got) != 1 || got[0].Profile != "individual_top6" {
		t.Errorf("模板展开错误: %+v", got)
	}
	if got := targets["EVT_TEAM"]; len(got) != 1 || got[0].Profile != "special_top3" {
		t.Errorf("模板展开错误: %+v", got)
	}
	if got, ok := targets["EVT_MATCH"]; !ok || len(got) != 0 {
		t.Errorf("override 的 channels: [] 应清空通道: %+v", got)
	}
	if _, ok := targets["EVT_GHOST"]; ok {
		t.Error("库里不存在的项目不应出现在目标状态里")
	}
	if len(unknown) != 1 || unknown[0] != "EVT_GHOST" {
		t.Errorf("未知项目识别错误: %v", unknown)
	}
}

// TestResolveTargetsClearsChannelsForUnscored 验证「只排名不计分」的项目固定解析成 0 通道（口径 2）：
// 否则它会继承模板通道，把名次带进奖牌榜。
func TestResolveTargetsClearsChannelsForUnscored(t *testing.T) {
	cur := currentSnapshot(t)
	cur.Events = append(cur.Events, EventInfo{
		ID: 4, Code: "EVT_NOSCORE", Name: "只排名示例",
		EventType: domain.EventTypeIndividual, ResultType: domain.ResultTypeTime,
		Scored: false, Multiplier: 1,
		Channels: []Channel{{Scope: domain.ScopeAthlete, Basis: domain.BasisResult, Profile: "individual_top6"}},
	})

	t.Run("继承模板的项目也被清空", func(t *testing.T) {
		next, err := Parse([]byte(nextPackYAML))
		if err != nil {
			t.Fatalf("Parse: %v", err)
		}
		targets, _, err := resolveTargets(cur, next)
		if err != nil {
			t.Fatalf("resolveTargets: %v", err)
		}
		if got, ok := targets["EVT_NOSCORE"]; !ok || len(got) != 0 {
			t.Fatalf("不计分项目的目标通道 = %+v，期望空", got)
		}

		cs, err := Diff(cur, next)
		if err != nil {
			t.Fatalf("Diff: %v", err)
		}
		removed := false
		for _, c := range cs.Channels {
			if c.EventCode == "EVT_NOSCORE" && c.Kind == ChangeRemoved && len(c.After) == 0 {
				removed = true
			}
		}
		if !removed {
			t.Errorf("差异预览应显示不计分项目的通道被清空: %+v", cs.Channels)
		}
	})

	t.Run("override 写了通道也清空", func(t *testing.T) {
		pack := *cur.Pack
		pack.EventOverrides = append(pack.EventOverrides, EventOverride{
			EventCode: "EVT_NOSCORE",
			Scored:    BoolPtr(false),
			Channels:  ChannelListPtr([]Channel{{Scope: domain.ScopeAthlete, Basis: domain.BasisResult, Profile: "individual_top6"}}),
		})
		targets, _, err := resolveTargets(cur, &pack)
		if err != nil {
			t.Fatalf("resolveTargets: %v", err)
		}
		if got, ok := targets["EVT_NOSCORE"]; !ok || len(got) != 0 {
			t.Fatalf("不计分项目的目标通道 = %+v，期望空", got)
		}
	})
}