package web

import (
	"context"
	"net/http"
	"net/url"
	"strings"
	"testing"

	"sourcecraft.dev/bigbes/sr-ht-dolt/browse"
	"sourcecraft.dev/bigbes/sr-ht-dolt/core"
)

// --- fixtures ----------------------------------------------------------------

// beadsTables is a schema fingerprint that Applies should accept: issues (with
// id + status) + dependencies both present.
func beadsTables() []browse.TableInfo {
	return []browse.TableInfo{
		{Name: "issues", Columns: []browse.ColumnInfo{
			{Name: "id", PrimaryKey: true}, {Name: "status"},
		}},
		{Name: "dependencies", Columns: []browse.ColumnInfo{{Name: "id", PrimaryKey: true}}},
		{Name: "labels"},
	}
}

// beadsFixture wires a fakeSession whose per-table Rows model a small parade:
//   - i-open   : open, ready         → Lined Up
//   - i-prog   : in_progress         → Rolling
//   - i-done   : closed              → Past Stand
//   - i-blocked: open, blocked by i-open (a "blocks" dep to a non-closed target)
//     and also carries is_blocked=1  → Stalled
//
// The issues page deliberately orders its columns id,title,status,priority,...
// with is_blocked LAST so column-name mapping (not positional) is exercised.
func beadsFixture() *fakeSession {
	issues := &browse.RowPage{
		// Column order chosen so nothing is at a "natural" index; is_blocked is last
		// and close_reason sits mid-row so name (not positional) mapping is exercised.
		Columns: []string{"id", "title", "status", "priority", "issue_type", "assignee", "created_at", "closed_at", "close_reason", "is_blocked"},
		Rows: [][]string{
			{"i-open", "Ready to roll", "open", "1", "feature", "alice", "2024-01-01", "NULL", "NULL", "0"},
			{"i-prog", "Under way", "in_progress", "0", "bug", "bob", "2024-01-02", "NULL", "NULL", "0"},
			{"i-done", "Finished", "closed", "2", "chore", "carol", "2024-01-03", "2024-01-04", "Fixed in commit abc123", "0"},
			{"i-blocked", "Waiting", "open", "1", "feature", "dave", "2024-01-04", "NULL", "NULL", "1"},
		},
		Total: 4,
	}
	// i-blocked depends on i-open (blocks, target open → keeps it Stalled).
	// i-open is depended on by i-blocked → i-open.Blocks == 1.
	deps := &browse.RowPage{
		Columns: []string{"id", "issue_id", "depends_on_issue_id", "type"},
		Rows: [][]string{
			{"d1", "i-blocked", "i-open", "blocks"},
		},
		Total: 1,
	}
	labels := &browse.RowPage{
		Columns: []string{"issue_id", "label"},
		Rows: [][]string{
			{"i-open", "backend"},
			{"i-open", "urgent"},
		},
		Total: 2,
	}
	statuses := &browse.RowPage{
		Columns: []string{"name", "category"},
		Rows: [][]string{
			{"open", "open"},
			{"in_progress", "in_progress"},
			{"closed", "closed"},
		},
		Total: 3,
	}
	comments := &browse.RowPage{
		Columns: []string{"issue_id", "author", "text", "created_at"},
		Rows: [][]string{
			{"i-open", "alice", "first!", "2024-01-05"},
			{"i-prog", "bob", "not this one", "2024-01-06"},
		},
		Total: 2,
	}
	// i-done's closure is recorded as a `closed` audit event carrying the reason
	// (the only place the reason now surfaces — there is no standalone block).
	events := &browse.RowPage{
		Columns: []string{"id", "issue_id", "event_type", "actor", "old_value", "new_value", "comment", "created_at"},
		Rows: [][]string{
			{"e1", "i-done", "closed", "carol", "NULL", "Fixed in commit abc123", "NULL", "2024-01-03 12:00:00"},
		},
		Total: 1,
	}
	return &fakeSession{
		branches: []browse.Branch{{Name: "main", Head: "abcdef1234567890"}},
		tables:   beadsTables(),
		rowsByTable: map[string]*browse.RowPage{
			"issues":          issues,
			"dependencies":    deps,
			"labels":          labels,
			"custom_statuses": statuses,
			"comments":        comments,
			"events":          events,
		},
	}
}

// laneBySlug finds a lane in a built board by its slug.
func laneBySlug(d *BeadsData, slug string) *BeadsLane {
	for i := range d.Lanes {
		if d.Lanes[i].Slug == slug {
			return &d.Lanes[i]
		}
	}
	return nil
}

// cardIDs lists the ids of a lane's cards.
func cardIDs(l *BeadsLane) []string {
	if l == nil {
		return nil
	}
	out := make([]string, len(l.Issues))
	for i, c := range l.Issues {
		out[i] = c.ID
	}
	return out
}

// --- Applies -----------------------------------------------------------------

func TestBeadsApplies(t *testing.T) {
	v := &beadsView{}
	if !v.Applies(beadsTables()) {
		t.Fatalf("Applies should be true when issues+dependencies (with id+status) present")
	}
	// Missing dependencies → not a beads DB.
	if v.Applies([]browse.TableInfo{
		{Name: "issues", Columns: []browse.ColumnInfo{{Name: "id"}, {Name: "status"}}},
	}) {
		t.Fatalf("Applies should be false without a dependencies table")
	}
	// issues present but lacking status column → guard rejects.
	if v.Applies([]browse.TableInfo{
		{Name: "issues", Columns: []browse.ColumnInfo{{Name: "id"}}},
		{Name: "dependencies"},
	}) {
		t.Fatalf("Applies should be false when issues lacks a status column")
	}
	// Unrelated schema.
	if v.Applies([]browse.TableInfo{{Name: "widgets"}}) {
		t.Fatalf("Applies should be false for an unrelated schema")
	}
}

// --- board mode --------------------------------------------------------------

func TestBeadsBuildBoardLanes(t *testing.T) {
	v := &beadsView{}
	got, err := v.Build(context.Background(), beadsFixture(), &core.Repo{OwnerName: "alice", Name: "db"}, "main", url.Values{})
	if err != nil {
		t.Fatalf("Build: %v", err)
	}
	d, ok := got.(*BeadsData)
	if !ok {
		t.Fatalf("Build returned %T, want *BeadsData", got)
	}
	if d.Mode != "board" {
		t.Fatalf("Mode = %q, want board", d.Mode)
	}

	checks := map[string][]string{
		"rolling":    {"i-prog"},
		"lined-up":   {"i-open"},
		"stalled":    {"i-blocked"},
		"past-stand": {"i-done"},
	}
	for slug, want := range checks {
		got := cardIDs(laneBySlug(d, slug))
		if strings.Join(got, ",") != strings.Join(want, ",") {
			t.Errorf("lane %s = %v, want %v", slug, got, want)
		}
	}

	if d.Counts.Rolling != 1 || d.Counts.LinedUp != 1 || d.Counts.Stalled != 1 || d.Counts.PastStand != 1 {
		t.Errorf("counts = %+v, want 1 each", d.Counts)
	}
	if d.Counts.Total != 4 || d.Total != 4 {
		t.Errorf("total = %d/%d, want 4", d.Counts.Total, d.Total)
	}
}

func TestBeadsBuildBoardCounts(t *testing.T) {
	v := &beadsView{}
	got, _ := v.Build(context.Background(), beadsFixture(), &core.Repo{OwnerName: "a", Name: "b"}, "main", url.Values{})
	d := got.(*BeadsData)

	// i-blocked depends on i-open → i-blocked.BlockedBy==1, i-open.Blocks==1.
	blocked := laneBySlug(d, "stalled").Issues[0]
	if blocked.ID != "i-blocked" || blocked.BlockedBy != 1 || blocked.Blocks != 0 {
		t.Errorf("i-blocked = %+v, want BlockedBy=1 Blocks=0", blocked)
	}
	open := laneBySlug(d, "lined-up").Issues[0]
	if open.ID != "i-open" || open.Blocks != 1 || open.BlockedBy != 0 {
		t.Errorf("i-open = %+v, want Blocks=1 BlockedBy=0", open)
	}
	// Labels attach by issue_id.
	if strings.Join(open.Labels, ",") != "backend,urgent" {
		t.Errorf("i-open labels = %v, want [backend urgent]", open.Labels)
	}
}

// TestBeadsBlockedByDepOnly proves the dependency-derived block signal works
// even when is_blocked is not set: an issue with a "blocks" dep to a non-closed
// target lands in Stalled; the same dep to a CLOSED target does not.
func TestBeadsBlockedByDepOnly(t *testing.T) {
	sess := &fakeSession{
		tables: beadsTables(),
		rowsByTable: map[string]*browse.RowPage{
			"issues": {
				Columns: []string{"id", "status", "is_blocked"},
				Rows: [][]string{
					{"a", "open", "0"},   // blocked by open b → Stalled
					{"b", "open", "0"},   // ready → Lined Up
					{"c", "open", "0"},   // "blocked" by closed d → NOT stalled → Lined Up
					{"d", "closed", "0"}, // Past Stand
				},
				Total: 4,
			},
			"dependencies": {
				Columns: []string{"issue_id", "depends_on_issue_id", "type"},
				Rows: [][]string{
					{"a", "b", "blocks"},
					{"c", "d", "blocks"},
				},
				Total: 2,
			},
		},
	}
	v := &beadsView{}
	got, err := v.Build(context.Background(), sess, &core.Repo{OwnerName: "a", Name: "b"}, "main", url.Values{})
	if err != nil {
		t.Fatalf("Build: %v", err)
	}
	d := got.(*BeadsData)
	if ids := cardIDs(laneBySlug(d, "stalled")); strings.Join(ids, ",") != "a" {
		t.Errorf("stalled = %v, want [a] (blocked by open dep only)", ids)
	}
	if ids := cardIDs(laneBySlug(d, "lined-up")); strings.Join(ids, ",") != "b,c" {
		t.Errorf("lined-up = %v, want [b c] (c's blocker is closed)", ids)
	}
}

// --- detail mode -------------------------------------------------------------

func TestBeadsBuildDetail(t *testing.T) {
	v := &beadsView{}
	q := url.Values{}
	q.Set("issue", "i-open")
	got, err := v.Build(context.Background(), beadsFixture(), &core.Repo{OwnerName: "a", Name: "b"}, "main", q)
	if err != nil {
		t.Fatalf("Build: %v", err)
	}
	d := got.(*BeadsData)
	if d.Mode != "detail" {
		t.Fatalf("Mode = %q, want detail", d.Mode)
	}
	if d.Issue == nil || d.Issue.ID != "i-open" || d.Issue.Title != "Ready to roll" {
		t.Fatalf("Issue = %+v, want i-open/Ready to roll", d.Issue)
	}
	if strings.Join(d.Issue.Labels, ",") != "backend,urgent" {
		t.Errorf("labels = %v", d.Issue.Labels)
	}
	// i-open is depended on by i-blocked (incoming), and depends on nothing.
	if len(d.DependsOn) != 0 {
		t.Errorf("DependsOn = %v, want none", d.DependsOn)
	}
	if len(d.DependedOnBy) != 1 || d.DependedOnBy[0].IssueID != "i-blocked" {
		t.Errorf("DependedOnBy = %+v, want [i-blocked]", d.DependedOnBy)
	}
	// Only i-open's comment shows in its thread.
	if len(d.Comments) != 1 || d.Comments[0].Author != "alice" || d.Comments[0].Text != "first!" {
		t.Errorf("Comments = %+v, want single alice comment", d.Comments)
	}
}

func TestBeadsBuildDetailOutgoingEdge(t *testing.T) {
	v := &beadsView{}
	q := url.Values{}
	q.Set("issue", "i-blocked")
	got, _ := v.Build(context.Background(), beadsFixture(), &core.Repo{OwnerName: "a", Name: "b"}, "main", q)
	d := got.(*BeadsData)
	if len(d.DependsOn) != 1 || d.DependsOn[0].IssueID != "i-open" || d.DependsOn[0].Title != "Ready to roll" {
		t.Fatalf("DependsOn = %+v, want [i-open/Ready to roll]", d.DependsOn)
	}
	if d.DependsOn[0].Type != "blocks" || d.DependsOn[0].Closed {
		t.Errorf("edge = %+v, want type=blocks not-closed", d.DependsOn[0])
	}
}

// --- end to end --------------------------------------------------------------

func TestBeadsHandleViewBoard(t *testing.T) {
	h := newHarness(t)
	h.store.add(&core.Repo{Name: "db", OwnerID: 1, OwnerName: "alice", Path: "/d", Visibility: core.VisibilityPublic})
	h.browse.sess = beadsFixture()
	setViews(t, h, &beadsView{})

	rec := h.do("GET", "/~alice/db/view/beads", nil, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("board: got %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	body := rec.Body.String()
	for _, want := range []string{"Rolling", "Lined Up", "Stalled", "Past Stand", "Ready to roll", "beads-summary"} {
		if !strings.Contains(body, want) {
			t.Errorf("board body missing %q", want)
		}
	}
	// The Tables tab must remain reachable from the view.
	if !strings.Contains(body, "/~alice/db/tree/") {
		t.Errorf("board missing Tables tab link; body=%s", body)
	}
}

func TestBeadsHandleViewDetail(t *testing.T) {
	h := newHarness(t)
	h.store.add(&core.Repo{Name: "db", OwnerID: 1, OwnerName: "alice", Path: "/d", Visibility: core.VisibilityPublic})
	h.browse.sess = beadsFixture()
	setViews(t, h, &beadsView{})

	rec := h.do("GET", "/~alice/db/view/beads?issue=i-blocked", nil, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("detail: got %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	body := rec.Body.String()
	if !strings.Contains(body, "Waiting") {
		t.Errorf("detail missing issue title; body=%s", body)
	}
	if !strings.Contains(body, "Depends on") || !strings.Contains(body, "i-open") {
		t.Errorf("detail missing dependency edge; body=%s", body)
	}
	if !strings.Contains(body, "Back to the parade") {
		t.Errorf("detail missing back link; body=%s", body)
	}
}

// A closed issue's detail pane must surface its close reason (and the closed
// timestamp), so the resolution recorded by `bd close -r` is not lost.
// TestBeadsDetailShowsCloseReason: the close reason surfaces through the History
// tab's `closed` event, not a standalone block (which was removed).
func TestBeadsDetailShowsCloseReason(t *testing.T) {
	h := newHarness(t)
	h.store.add(&core.Repo{Name: "db", OwnerID: 1, OwnerName: "alice", Path: "/d", Visibility: core.VisibilityPublic})
	h.browse.sess = beadsFixture()
	setViews(t, h, &beadsView{})

	rec := h.do("GET", "/~alice/db/view/beads?issue=i-done", nil, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("detail: got %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	body := rec.Body.String()
	for _, want := range []string{"closed the issue", "Fixed in commit abc123"} {
		if !strings.Contains(body, want) {
			t.Errorf("closed-issue history missing %q; body=%s", want, body)
		}
	}
	// The old standalone block is gone; the reason lives only in the timeline.
	if strings.Contains(body, "<h4>Close reason</h4>") {
		t.Errorf("standalone Close reason block should be removed; body=%s", body)
	}
}

// --- epic mode + history -----------------------------------------------------

// beadsEpicFixture models an epic (i-epic) with three parent-child children —
// one closed, one open, one in-progress — plus a comment and three audit events
// on the epic, so both the subtask rollup and the merged history are exercised.
func beadsEpicFixture() *fakeSession {
	issues := &browse.RowPage{
		Columns: []string{"id", "title", "status", "priority", "issue_type", "assignee", "created_at", "is_blocked"},
		Rows: [][]string{
			{"i-epic", "Big Epic", "open", "1", "epic", "", "2024-01-01", "0"},
			{"i-c1", "Child one", "open", "2", "task", "alice", "2024-01-02", "0"},
			{"i-c2", "Child two", "closed", "1", "task", "bob", "2024-01-03", "0"},
			{"i-c3", "Child three", "in_progress", "0", "bug", "carol", "2024-01-04", "0"},
		},
		Total: 4,
	}
	// Each child is the "from" side of a parent-child edge pointing at the epic.
	deps := &browse.RowPage{
		Columns: []string{"id", "issue_id", "depends_on_issue_id", "type"},
		Rows: [][]string{
			{"d1", "i-c1", "i-epic", "parent-child"},
			{"d2", "i-c2", "i-epic", "parent-child"},
			{"d3", "i-c3", "i-epic", "parent-child"},
		},
		Total: 3,
	}
	statuses := &browse.RowPage{
		Columns: []string{"name", "category"},
		Rows: [][]string{
			{"open", "open"}, {"in_progress", "in_progress"}, {"closed", "closed"},
		},
		Total: 3,
	}
	comments := &browse.RowPage{
		Columns: []string{"issue_id", "author", "text", "created_at"},
		Rows: [][]string{
			{"i-epic", "alice", "kickoff", "2024-01-05 09:00:00"},
			{"i-c1", "bob", "unrelated", "2024-01-06 09:00:00"},
		},
		Total: 2,
	}
	events := &browse.RowPage{
		Columns: []string{"id", "issue_id", "event_type", "actor", "old_value", "new_value", "comment", "created_at"},
		Rows: [][]string{
			{"e1", "i-epic", "created", "Eugene", "NULL", "NULL", "NULL", "2024-01-01 08:00:00"},
			{"e2", "i-epic", "status_changed", "Eugene", `{"status":"open"}`, `{"status":"in_progress"}`, "NULL", "2024-01-02 10:00:00"},
			{"e3", "i-epic", "updated", "Eugene", "NULL", `{"priority":0}`, "NULL", "2024-01-03 11:00:00"},
			{"e4", "i-epic", "label_added", "Eugene", "NULL", "NULL", "Added label: milestone:m3", "2024-01-04 09:00:00"},
			{"e9", "i-c1", "created", "Eugene", "NULL", "NULL", "NULL", "2024-01-02 08:00:00"},
		},
		Total: 5,
	}
	return &fakeSession{
		branches: []browse.Branch{{Name: "main", Head: "abcdef1234567890"}},
		tables:   beadsTables(),
		rowsByTable: map[string]*browse.RowPage{
			"issues":          issues,
			"dependencies":    deps,
			"custom_statuses": statuses,
			"comments":        comments,
			"events":          events,
		},
	}
}

func TestBeadsEpicMode(t *testing.T) {
	v := &beadsView{}
	raw, err := v.Build(context.Background(), beadsEpicFixture(), nil, "main", url.Values{"issue": {"i-epic"}})
	if err != nil {
		t.Fatalf("build: %v", err)
	}
	d := raw.(*BeadsData)
	if d.Mode != "epic" {
		t.Fatalf("Mode = %q, want epic", d.Mode)
	}
	if d.SubtaskTotal != 3 || d.SubtaskDone != 1 {
		t.Errorf("rollup = %d/%d, want 1/3", d.SubtaskDone, d.SubtaskTotal)
	}
	if d.SubtaskPct() != 33 {
		t.Errorf("pct = %d, want 33", d.SubtaskPct())
	}
	// Sorted open-work-first (in_progress p0, then open p2), closed sinks last.
	gotIDs := []string{d.Subtasks[0].ID, d.Subtasks[1].ID, d.Subtasks[2].ID}
	wantIDs := []string{"i-c3", "i-c1", "i-c2"}
	for i := range wantIDs {
		if gotIDs[i] != wantIDs[i] {
			t.Errorf("subtask order = %v, want %v", gotIDs, wantIDs)
			break
		}
	}
	if d.Subtasks[2].Category != "closed" {
		t.Errorf("last subtask category = %q, want closed", d.Subtasks[2].Category)
	}
}

func TestBeadsHistoryMerge(t *testing.T) {
	v := &beadsView{}
	raw, err := v.Build(context.Background(), beadsEpicFixture(), nil, "main", url.Values{"issue": {"i-epic"}})
	if err != nil {
		t.Fatalf("build: %v", err)
	}
	d := raw.(*BeadsData)

	// Only the epic's own comment shows in the Comments tab (not i-c1's).
	if len(d.Comments) != 1 || d.Comments[0].Text != "kickoff" {
		t.Fatalf("comments = %+v, want just the epic's kickoff", d.Comments)
	}
	// History merges the epic's 1 comment + 4 events (i-c1's are excluded), time-sorted.
	if len(d.History) != 5 {
		t.Fatalf("history len = %d, want 5: %+v", len(d.History), d.History)
	}
	for i := 1; i < len(d.History); i++ {
		if d.History[i-1].CreatedAt > d.History[i].CreatedAt {
			t.Errorf("history not time-sorted at %d: %q > %q", i, d.History[i-1].CreatedAt, d.History[i].CreatedAt)
		}
	}
	if d.History[0].Kind != "event" || d.History[0].Summary != "created the issue" {
		t.Errorf("first history = %+v, want created event", d.History[0])
	}
	last := d.History[len(d.History)-1]
	if last.Kind != "comment" || last.Text != "kickoff" {
		t.Errorf("last history = %+v, want the kickoff comment", last)
	}
	// Humanized change lines, and a label event collapsed to one line with no
	// redundant "Added label:" body.
	var sawStatus, sawUpdate, sawLabel bool
	for _, a := range d.History {
		switch a.Summary {
		case "changed status to in_progress":
			sawStatus = true
		case "updated priority to 0":
			sawUpdate = true
		case "added label milestone:m3":
			sawLabel = true
			if a.Text != "" {
				t.Errorf("label event should have no body, got %q", a.Text)
			}
		}
		if strings.Contains(a.Text, "Added label:") {
			t.Errorf("label note leaked into a history body: %+v", a)
		}
	}
	if !sawStatus || !sawUpdate || !sawLabel {
		t.Errorf("history missing humanized lines; status=%v update=%v label=%v", sawStatus, sawUpdate, sawLabel)
	}
}

func TestBeadsEpicViewRender(t *testing.T) {
	h := newHarness(t)
	h.store.add(&core.Repo{Name: "db", OwnerID: 1, OwnerName: "alice", Path: "/d", Visibility: core.VisibilityPublic})
	h.browse.sess = beadsEpicFixture()
	setViews(t, h, &beadsView{})

	rec := h.do("GET", "/~alice/db/view/beads?issue=i-epic", nil, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("epic view: got %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	body := rec.Body.String()
	for _, want := range []string{"Subtasks", "1 of 3 done", "epic-progress", "Child three", "History", "changed status to in_progress"} {
		if !strings.Contains(body, want) {
			t.Errorf("epic render missing %q", want)
		}
	}
}