package web

import (
	"context"
	"net/http"
	"strings"
	"time"

	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
)

// The people page's tabs. One page, because people, the limits they are held
// to and what they used are three views of one tree: managing a team meant its
// members on one page, its quota on another and its spend on a third, each
// linking to the others. Each tab keeps the address it had as a page of its
// own, so links and bookmarks to /admin/quotas and /admin/usage still land.
const (
	tabPeople = "people"
	tabLimits = "limits"
	tabUsage  = "usage"
)

// peopleView is what a request asks the people page for.
type peopleView struct {
	Tab      string
	Msg, Err string
	// Open is the project shown expanded in the tree.
	Open string
}

type peopleData struct {
	Nav Nav
	Tab string
	// The tabs this server has, each built only when it is the one shown.
	HasPeople, HasLimits, HasUsage bool
	Users                          *adminUsersData
	Quotas                         *adminQuotasData
	Usage                          *adminUsageData
	// Detail is the branch or person chosen in the tree, nil when none is.
	Detail *peopleDetail
	// Sel is what was chosen, "team:<id>" or "user:<id>", for links to keep.
	Sel     string
	Pending int
	Version string
	Now     string
}

// peopleDetail is one organization, team, project or person, with everything
// the three tabs say about it in one place.
type peopleDetail struct {
	Kind store.Scope
	ID   string
	// Name is what it is called, Path where it sits.
	Name, Path string

	// Limits is its own quota row, with what it is held to from above; nil
	// for a person, or where limits are not mounted.
	Limits *quotaRow
	// Person is a person's own limit.
	Person *personRow
	// Memberships are where a person is.
	Memberships []store.Membership
	// Capacity is its capacity quota, nil when it has none.
	Capacity    *capacityRow
	HasCapacity bool
	BudgetsBind bool

	// Its use over the last week, and the totals beside it.
	HasUsage                bool
	Requests, Tokens, Spend TimeSeries
	Totals                  usageRow
	Priced                  bool
	// Stats is how its requests ended and how long they took, over the
	// same week; HasStats is false where the store does not say.
	Stats                    store.GroupStats
	HasStats                 bool
	UsageWindow, QuotaWindow string

	CSRF string
}

// The panel names what was chosen by its kind, looked up by the value it is
// stored as. Its own words rather than the limits tab's, because a panel
// about a user says "person".
func init() {
	registerKeys("people.kind.org", "people.kind.team", "people.kind.project", "people.kind.user")
}

// renderPeople draws the people page on the tab asked for.
func (p *AccountPages) renderPeople(w http.ResponseWriter, r *http.Request, admin store.User, v peopleView) {
	d := peopleData{
		Nav: navFrom(r, "people"), Tab: v.Tab,
		HasPeople: p.peopleStore != nil, HasLimits: p.quotaStore != nil, HasUsage: p.usageStore != nil,
		Sel:     r.FormValue("sel"),
		Version: p.version, Now: time.Now().UTC().Format(time.RFC3339),
	}
	switch {
	case d.Tab == tabPeople && d.HasPeople:
		u := p.buildUsers(r, p.peopleStore, admin, v.Msg, v.Err, v.Open)
		d.Users, d.Pending = &u, len(u.Pending)
		if d.Sel != "" {
			d.Detail = p.detail(r, d.Sel, &u)
		}
	case d.Tab == tabLimits && d.HasLimits:
		q := p.buildQuotas(r, p.quotaStore, v.Msg, v.Err)
		d.Quotas = &q
	case d.Tab == tabUsage && d.HasUsage:
		u := p.buildUsage(r, p.usageStore, p.usagePriced)
		d.Usage = &u
	default:
		// The tab asked for is not mounted here: the first one that is.
		switch {
		case d.HasPeople:
			v.Tab = tabPeople
		case d.HasLimits:
			v.Tab = tabLimits
		case d.HasUsage:
			v.Tab = tabUsage
		default:
			http.NotFound(w, r)
			return
		}
		p.renderPeople(w, r, admin, v)
		return
	}
	render(w, r, "admin_people", d)
}

// usageGrouping is the grouping a branch's or a person's use is read under.
func usageGrouping(kind store.Scope) (store.Grouping, bool) {
	switch kind {
	case store.ScopeOrg:
		return store.GroupByOrg, true
	case store.ScopeTeam:
		return store.GroupByTeam, true
	case store.ScopeProject:
		return store.GroupByProject, true
	case store.ScopeUser:
		return store.GroupByUser, true
	}
	return "", false
}

// detail gathers what the page knows about one branch or person.
func (p *AccountPages) detail(r *http.Request, sel string, u *adminUsersData) *peopleDetail {
	kind, id, ok := strings.Cut(sel, ":")
	if !ok || id == "" {
		return nil
	}
	ctx := r.Context()
	l := langOf(r)
	d := &peopleDetail{Kind: store.Scope(kind), ID: id, CSRF: csrfFor(r),
		UsageWindow: l.T("usage.window.7d"), QuotaWindow: l.T("quotas.since")}
	if !p.nameDetail(d, u) {
		return nil
	}

	if p.quotaStore != nil {
		d.BudgetsBind = p.priced != nil && p.priced.AnythingPriced()
		p.limitsDetail(ctx, l, d)
	}
	if p.capacity != nil && d.Kind != store.ScopeUser {
		d.HasCapacity = true
		if views, err := p.capacity.QuotaViews(ctx); err == nil {
			for _, v := range views {
				if v.Scope == sel {
					c := capacityRow{QuotaView: v,
						GPUs:   l.capCell(v.Holds.GPUs, v.Guarantee.GPUs, v.Limit.GPUs),
						Cores:  l.capCell(v.Holds.CPUCores, v.Guarantee.CPUCores, v.Limit.CPUCores),
						Memory: l.capCell(v.Holds.MemoryGB, v.Guarantee.MemoryGB, v.Limit.MemoryGB)}
					d.Capacity = &c
				}
			}
		}
	}
	if p.usageStore != nil {
		p.usageDetail(ctx, l, d)
	}
	return d
}

// nameDetail finds what was chosen in the tree or among the accounts, and
// says whether it is there at all.
func (p *AccountPages) nameDetail(d *peopleDetail, u *adminUsersData) bool {
	if d.Kind == store.ScopeUser {
		for _, a := range u.Accounts {
			if a.ID == d.ID {
				d.Name, d.Path, d.Memberships = a.Email, a.Name, a.Memberships
				return true
			}
		}
		return false
	}
	for _, o := range u.Tree {
		if d.Kind == store.ScopeOrg && o.ID == d.ID {
			d.Name, d.Path = o.Name, o.Name
			return true
		}
		for _, t := range o.Teams {
			if d.Kind == store.ScopeTeam && t.ID == d.ID {
				d.Name, d.Path = t.Name, o.Name+" / "+t.Name
				return true
			}
			for _, pr := range t.Projects {
				if d.Kind == store.ScopeProject && pr.ID == d.ID {
					d.Name, d.Path = pr.Name, o.Name+" / "+t.Name+" / "+pr.Name
					return true
				}
			}
		}
	}
	return false
}

// limitsDetail is the branch's own quota row, or the person's own limit.
func (p *AccountPages) limitsDetail(ctx context.Context, l *Lang, d *peopleDetail) {
	s := p.quotaStore
	limits, err := s.AllLimits(ctx)
	if err != nil {
		p.log.Warn("could not read the limits for a detail panel", "err", err)
		return
	}
	since := time.Now().Add(-quotaWindow)
	if d.Kind == store.ScopeUser {
		for _, row := range p.personRowsIn(ctx, l, s, limits, since, "") {
			if row.ID == d.ID {
				row := row
				d.Person = &row
			}
		}
		return
	}
	tree, err := s.Tree(ctx)
	if err != nil {
		return
	}
	for _, row := range quotaRowsIn(l, tree, limits, p.spendByScope(ctx, s, since)) {
		if row.Scope == d.Kind && row.ID == d.ID {
			ms := store.MemberScope(row.Scope)
			if m, ok := limits[store.LimitOwner{Scope: ms, ID: row.ID}.CounterKey()]; ok {
				row.MemberRaw, row.Member = fieldsOf(m), l.limitsText(m)
			}
			d.Limits = &row
			return
		}
	}
}

// usageDetail is the branch's or person's use over the last week, drawn.
func (p *AccountPages) usageDetail(ctx context.Context, l *Lang, d *peopleDetail) {
	g, ok := usageGrouping(d.Kind)
	if !ok {
		return
	}
	win := windowFor("7d")
	rows, err := p.usageStore.UsageBucketsBy(ctx, g, time.Now().Add(-win.Span), win.Width)
	if err != nil {
		p.log.Warn("could not read usage for a detail panel", "sel", string(d.Kind)+":"+d.ID, "err", err)
		return
	}
	d.HasUsage = true
	d.Priced = p.usagePriced != nil && p.usagePriced.AnythingPriced()
	if sr, ok := p.usageStore.(StatsReader); ok {
		if stats, err := sr.StatsBy(ctx, g, time.Now().Add(-win.Span)); err == nil {
			d.Stats, d.HasStats = stats[d.ID], true
		}
	}
	for _, s := range rows {
		if s.ID == d.ID {
			var table []usageRow
			d.Requests, d.Tokens, d.Spend, table = usageChartsIn(l, []store.UsageSeries{s})
			d.Totals = table[0]
			return
		}
	}
}