// milestones_test.go — MilestoneOverview 的單元測試（#31）。
//
// 資料源注入假實作（離線可測）；鍵序、null 表示、排序與 overdue
// 判定對照 gitea.py list_milestone_overview 的 Python 語義。
package workflow

import (
	"encoding/json"
	"strings"
	"testing"
	"time"
)

// fakeMilestoneSource 以記憶體資料實作 MilestoneSource。
type fakeMilestoneSource struct {
	orgs       []string
	repos      map[string][]Repo
	milestones map[string][]Milestone
	openIssues map[string][]Issue // key: owner/repo?milestone=<title>
}

func (f *fakeMilestoneSource) MyOrganizations() ([]string, error) { return f.orgs, nil }
func (f *fakeMilestoneSource) OrganizationRepositories(org string) ([]Repo, error) {
	return f.repos[org], nil
}
func (f *fakeMilestoneSource) OpenMilestones(owner, repo string) ([]Milestone, error) {
	return f.milestones[owner+"/"+repo], nil
}
func (f *fakeMilestoneSource) MilestoneOpenIssues(owner, repo, title string) ([]Issue, error) {
	return f.openIssues[owner+"/"+repo+"?milestone="+title], nil
}

func msPtr(s string) *string { return &s }
func idPtr(i int64) *int64   { return &i }

// newMilestoneFixture 建構情境：alterminal 兩倉庫、三里程碑
// （teai 有期限將至、agents 有逾期與無期限）。
func newMilestoneFixture() *fakeMilestoneSource {
	return &fakeMilestoneSource{
		orgs: []string{"alterminal"},
		repos: map[string][]Repo{"alterminal": {
			{Name: "agents", HasPullRequests: boolPtr(true)},
			{Name: "teai", HasPullRequests: boolPtr(true)},
			{Name: "empty-repo", Empty: true}, // 空倉庫應跳過
		}},
		milestones: map[string][]Milestone{
			"alterminal/agents": {
				{ID: idPtr(7), Title: "MVP", State: "open",
					DueOn: msPtr("2026-09-09T00:00:00Z"), UpdatedAt: "2026-09-01T00:00:00Z",
					OpenIssues: 3, ClosedIssues: 1},
				{ID: idPtr(8), Title: "v1", State: "open",
					DueOn: nil, UpdatedAt: "2026-09-02T00:00:00Z",
					OpenIssues: 1, ClosedIssues: 0},
			},
			"alterminal/teai": {
				{ID: idPtr(3), Title: "CLI", State: "open",
					DueOn: msPtr("2026-09-12T00:00:00Z"), UpdatedAt: "2026-09-05T00:00:00Z",
					OpenIssues: 2, ClosedIssues: 5},
			},
		},
		openIssues: map[string][]Issue{
			// agents MVP：一個未分派 issue、一個未分派 PR、一個已分派 issue。
			"alterminal/agents?milestone=MVP": {
				{Number: 31, Title: "總覽命令", State: "open",
					UpdatedAt:  "2026-09-10T01:00:00Z",
					Repository: &Repository{FullName: "alterminal/agents"},
					HTMLURL:    "https://gitea.alterminal.com/alterminal/agents/issues/31"},
				{Number: 32, Title: "文件", State: "open",
					UpdatedAt:   "2026-09-08T00:00:00Z",
					Repository:  &Repository{FullName: "alterminal/agents"},
					HTMLURL:     "https://gitea.alterminal.com/alterminal/agents/pulls/32",
					PullRequest: &pullMarker{}, User: &User{UserName: "alex"}},
				{Number: 33, Title: "已分派", State: "open",
					UpdatedAt:  "2026-09-07T00:00:00Z",
					Repository: &Repository{FullName: "alterminal/agents"},
					HTMLURL:    "https://gitea.alterminal.com/alterminal/agents/issues/33",
					Assignee:   &User{UserName: "queena"}},
			},
			// agents v1（無期限）：條目比里程碑本身新 → updated_at 取條目。
			"alterminal/agents?milestone=v1": {
				{Number: 40, Title: "無人理", State: "open",
					UpdatedAt:  "2026-09-09T23:30:00Z",
					Repository: &Repository{FullName: "alterminal/agents"},
					HTMLURL:    "https://gitea.alterminal.com/alterminal/agents/issues/40"},
			},
		},
	}
}

// TestMilestoneOverviewSortAndOverdue 驗證排序（期限近者在前、無期限在後）
// 與 overdue／due_hours 計算。
func TestMilestoneOverviewSortAndOverdue(t *testing.T) {
	now := time.Date(2026, 9, 10, 8, 0, 0, 0, time.UTC)
	entries, err := MilestoneOverview(newMilestoneFixture(), "https://gitea.alterminal.com", now)
	if err != nil {
		t.Fatalf("MilestoneOverview: %v", err)
	}
	if len(entries) != 3 {
		t.Fatalf("應有 3 筆（空倉庫跳過），得到 %d", len(entries))
	}
	// 排序：MVP（2026-09-09，已過期）→ CLI（2026-09-12）→ v1（無期限）。
	wantOrder := []string{"alterminal/agents#MVP", "alterminal/teai#CLI", "alterminal/agents#v1"}
	for i, want := range wantOrder {
		got := entries[i].Repo + "#" + entries[i].Title
		if got != want {
			t.Errorf("第 %d 筆應為 %s，得到 %s", i, want, got)
		}
	}
	// MVP：due 2026-09-09T00:00Z、now 09-10T08:00Z → 32 小時、逾期。
	if !entries[0].Overdue {
		t.Errorf("MVP 應逾期")
	}
	if entries[0].DueHours == nil || *entries[0].DueHours != 32.0 {
		t.Errorf("MVP due_hours 應 32.0，得到 %v", entries[0].DueHours)
	}
	// CLI：未到期。
	if entries[1].Overdue {
		t.Errorf("CLI 不應逾期")
	}
	// v1：無期限 → null。
	if entries[2].DueOn != nil || entries[2].DueHours != nil || entries[2].Overdue {
		t.Errorf("v1 無期限應為 null/false，得到 %+v", entries[2])
	}
}

// TestMilestoneOverviewUnassigned 驗證未分派條目摘要（issue 無 author、
// pull 帶 author）與 updated_at 取最大值。
func TestMilestoneOverviewUnassigned(t *testing.T) {
	now := time.Date(2026, 9, 10, 8, 0, 0, 0, time.UTC)
	entries, err := MilestoneOverview(newMilestoneFixture(), "https://gitea.alterminal.com", now)
	if err != nil {
		t.Fatalf("MilestoneOverview: %v", err)
	}
	var mvp *MilestoneEntry
	for i := range entries {
		if entries[i].Title == "MVP" {
			mvp = &entries[i]
		}
	}
	if mvp == nil {
		t.Fatalf("找不到 MVP")
	}
	// 未分派：#31（issue）、#32（PR, author=alex）；#33 已分派不列。
	if len(mvp.Unassigned) != 2 {
		t.Fatalf("MVP 應有 2 筆未分派，得到 %d：%+v", len(mvp.Unassigned), mvp.Unassigned)
	}
	if mvp.Unassigned[0].Type != "issue" || mvp.Unassigned[0].Number != 31 {
		t.Errorf("第一筆未分派應為 issue #31，得到 %+v", mvp.Unassigned[0])
	}
	if mvp.Unassigned[1].Type != "pull" || mvp.Unassigned[1].Number != 32 || mvp.Unassigned[1].Author != "alex" {
		t.Errorf("第二筆未分派應為 pull #32（author=alex），得到 %+v", mvp.Unassigned[1])
	}
	// updated_at：max(里程碑 09-01, #31 09-10T01:00Z) → 後者。
	if mvp.UpdatedAt == nil || *mvp.UpdatedAt != "2026-09-10T01:00:00+00:00" {
		t.Errorf("MVP updated_at 應取條目最大值 2026-09-10T01:00:00+00:00，得到 %v", mvp.UpdatedAt)
	}
	// url 組法。
	if mvp.URL != "https://gitea.alterminal.com/alterminal/agents/milestone/7" {
		t.Errorf("MVP url 應為 milestone/7，得到 %s", mvp.URL)
	}
}

// TestMilestoneOverviewJSONKeys 驗證 JSON 鍵集與鍵序與 gitea.py 一致，
// 以及 null／陣列空表示（unassigned 空 → []）。
func TestMilestoneOverviewJSONKeys(t *testing.T) {
	now := time.Date(2026, 9, 10, 8, 0, 0, 0, time.UTC)
	entries, err := MilestoneOverview(newMilestoneFixture(), "", now)
	if err != nil {
		t.Fatalf("MilestoneOverview: %v", err)
	}
	// v1：無期限、無未分派條目 → due_on/due_hours/updated_at 的 null 表示、
	// unassigned=[]、webBase 空 → url=""。
	var v1 *MilestoneEntry
	for i := range entries {
		if entries[i].Title == "v1" {
			v1 = &entries[i]
		}
	}
	if v1 == nil {
		t.Fatalf("找不到 v1")
	}
	// 手寫期望 JSON（縮排 2、鍵序照 gitea.py dict 實字序）。
	b, err := json.Marshal(v1)
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	// 以逐鍵比對為準（MarshalIndent 因自訂 MarshalJSON 不縮排內層）。
	var obj map[string]json.RawMessage
	if err := json.Unmarshal(b, &obj); err != nil {
		t.Fatalf("Unmarshal: %v", err)
	}
	wantKeys := []string{"repo", "id", "title", "url", "open_issues", "closed_issues",
		"due_on", "due_hours", "overdue", "unassigned", "updated_at"}
	// 鍵序：json.Unmarshal 到 map 會失序；改檢查原始字串的鍵出現順序。
	pos := -1
	for _, k := range wantKeys {
		i := strings.Index(string(b), `"`+k+`":`)
		if i < 0 {
			t.Fatalf("輸出缺少鍵 %q：%s", k, b)
		}
		if i < pos {
			t.Fatalf("鍵 %q 順序錯誤：%s", k, b)
		}
		pos = i
	}
	for _, kv := range []struct {
		key  string
		want string
	}{
		{"repo", `"alterminal/agents"`},
		{"due_on", `null`},
		{"due_hours", `null`},
		{"overdue", `false`},
		{"url", `""`},
	} {
		if got := string(obj[kv.key]); got != kv.want {
			t.Errorf("%s 應為 %s，得到 %s", kv.key, kv.want, got)
		}
	}
	if !strings.Contains(string(b), `"number":40`) {
		t.Errorf("未分派條目應含 number 40：%s", b)
	}
	// pull 條目的 author 鍵：有作者才輸出（無則不該出現 "author"）。
	if strings.Contains(string(obj["unassigned"]), `"author"`) {
		t.Errorf("issue 條目不應有 author 鍵：%s", obj["unassigned"])
	}
}

// TestMilestoneOverviewDueHoursRounding 驗證 due_hours 捨入到一位小數，
// 且 overdue 以未捨入值判定（0.04h → 0.0 但 overdue=true）。
func TestMilestoneOverviewDueHoursRounding(t *testing.T) {
	src := &fakeMilestoneSource{
		orgs:  []string{"alterminal"},
		repos: map[string][]Repo{"alterminal": {{Name: "r"}}},
		milestones: map[string][]Milestone{
			"alterminal/r": {
				{ID: idPtr(1), Title: "edge", State: "open",
					DueOn: msPtr("2026-09-10T07:57:36Z"), UpdatedAt: "2026-09-10T07:00:00Z"},
			},
		},
		openIssues: map[string][]Issue{},
	}
	now := time.Date(2026, 9, 10, 8, 0, 0, 0, time.UTC)
	entries, err := MilestoneOverview(src, "", now)
	if err != nil {
		t.Fatalf("MilestoneOverview: %v", err)
	}
	if len(entries) != 1 {
		t.Fatalf("應有 1 筆，得到 %d", len(entries))
	}
	// 144 秒 = 0.04 小時 → round1 → 0.0；未捨入 > 0 → overdue=true。
	b, err := json.Marshal(entries[0])
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	if !strings.Contains(string(b), `"due_hours":0.0`) {
		t.Errorf("due_hours 應捨入為 0.0：%s", b)
	}
	if !strings.Contains(string(b), `"overdue":true`) {
		t.Errorf("overdue 應以未捨入值判定為 true：%s", b)
	}
}