package api

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

	"github.com/jackc/pgx/v5"

	"github.com/loyaly/behavision-server/internal/auth"
)

// The platform administrator's remaining shell-only jobs, as endpoints:
// suspend or reinstate a company, reset its owner's password, delete it.
//
// All three are behind adminOnly (a principal with the role AND no client), and
// all three read the company id from the path. None takes a client id from a
// body - the same rule every tenant handler follows.

// PATCH /api/admin/clients/{id}  {"active": false}
//
// Suspension is the reversible step and it is complete: login refuses the
// company's users, the broker's visits are dropped at ingest, and every live
// session is revoked in the same transaction. Without the last, "suspend" would
// mean "suspend some time tomorrow", which is not what anybody pressing it
// believes they did.
func (s *Server) handleSetClientActive(w http.ResponseWriter, r *http.Request) {
	p := PrincipalFrom(r.Context())
	var in struct {
		Active *bool `json:"active"`
	}
	if err := decode(w, r, &in); err != nil {
		badRequest(w, err.Error())
		return
	}
	if in.Active == nil {
		badRequest(w, `"active" is required: true to reinstate, false to suspend`)
		return
	}
	row, revoked, err := s.Store.SetClientActive(r.Context(), r.PathValue("id"), *in.Active)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			writeErr(w, http.StatusNotFound, "not_found", "No such company.")
			return
		}
		s.serverError(w, "set client active", err)
		return
	}
	action := "client.suspended"
	if *in.Active {
		action = "client.reinstated"
	}
	s.Store.Audit(r.Context(), AuditEntry{
		ActorID: p.UserID, ActorKind: "user", Action: action,
		Entity: "client", EntityID: row.ID,
		Detail: map[string]any{"slug": row.Slug, "sessions_revoked": revoked},
	})
	writeJSON(w, http.StatusOK, map[string]any{"client": row, "sessions_revoked": revoked})
}

// POST /api/admin/clients/{id}/owner-password  {"email": "…"}
//
// The support case this exists for: the owner has locked themselves out and
// there is nobody above them in the company to reset it. The new password is
// generated, shown once, and every session that owner held is revoked. `email`
// picks the owner when the company has more than one; with exactly one it may
// be omitted.
func (s *Server) handleResetOwnerPassword(w http.ResponseWriter, r *http.Request) {
	p := PrincipalFrom(r.Context())
	clientID := r.PathValue("id")
	var in struct {
		Email string `json:"email"`
	}
	if err := decodeOptional(w, r, &in); err != nil {
		badRequest(w, err.Error())
		return
	}
	owners, err := s.Store.ClientOwners(r.Context(), clientID)
	if err != nil {
		s.serverError(w, "list owners", err)
		return
	}
	var target *TeamMember
	switch {
	case len(owners) == 0:
		writeErr(w, http.StatusNotFound, "not_found", "That company has no active owner.")
		return
	case in.Email != "":
		want := auth.NormalizeEmail(in.Email)
		for i := range owners {
			if owners[i].Email == want {
				target = &owners[i]
			}
		}
		if target == nil {
			writeErr(w, http.StatusNotFound, "not_found", "No active owner with that address.")
			return
		}
	case len(owners) == 1:
		target = &owners[0]
	default:
		emails := make([]string, 0, len(owners))
		for _, o := range owners {
			emails = append(emails, o.Email)
		}
		badRequest(w, "That company has several owners; say which with \"email\": "+strings.Join(emails, ", "))
		return
	}

	password, err := auth.RandomPassword()
	if err != nil {
		s.serverError(w, "generate password", err)
		return
	}
	hash, err := auth.HashPassword(password)
	if err != nil {
		s.serverError(w, "hash password", err)
		return
	}
	m, err := s.Store.ResetMemberPassword(r.Context(), clientID, target.ID, hash)
	if err != nil {
		s.serverError(w, "reset owner password", err)
		return
	}
	s.Store.Audit(r.Context(), AuditEntry{
		ActorID: p.UserID, ActorKind: "user", Action: "admin.reset_owner_password",
		Entity: "user", EntityID: m.ID, Detail: map[string]any{"email": m.Email, "client_id": clientID},
	})
	writeJSON(w, http.StatusOK, map[string]any{"email": m.Email, "password": password})
}

// DELETE /api/admin/clients/{id}  {"confirm": "<slug>"}
//
// Irreversible, and the data is biometric, so it is deliberately hard to do by
// accident: the company must already be suspended, and the request must repeat
// the slug. Objects go first - once the rows are gone nothing knows which files
// to remove - then the broker logins, then the rows (everything cascades from
// clients). A storage failure aborts before anything else is touched.
func (s *Server) handleDeleteClient(w http.ResponseWriter, r *http.Request) {
	p := PrincipalFrom(r.Context())
	clientID := r.PathValue("id")
	var in struct {
		Confirm string `json:"confirm"`
	}
	if err := decode(w, r, &in); err != nil {
		badRequest(w, err.Error())
		return
	}
	rows, err := s.Store.ListClients(r.Context())
	if err != nil {
		s.serverError(w, "list clients", err)
		return
	}
	var row *ClientRow
	for i := range rows {
		if rows[i].ID == clientID {
			row = &rows[i]
		}
	}
	if row == nil {
		writeErr(w, http.StatusNotFound, "not_found", "No such company.")
		return
	}
	if row.Active {
		writeErr(w, http.StatusConflict, "still_active",
			"Suspend the company first (PATCH active=false). Deleting is the second step, not the first.")
		return
	}
	if strings.TrimSpace(in.Confirm) != row.Slug {
		badRequest(w, "Repeat the company's slug in \"confirm\" to delete it.")
		return
	}

	keys, err := s.Store.ClientImageKeys(r.Context(), clientID)
	if err != nil {
		s.serverError(w, "list images for client delete", err)
		return
	}
	if s.Blob != nil {
		for _, key := range keys {
			if isDBKey(key) {
				continue // goes with the rows
			}
			if err := s.Blob.Delete(r.Context(), key); err != nil {
				s.logf("ERROR delete client %s: cannot delete %s: %v", row.Slug, key, err)
				writeErr(w, http.StatusBadGateway, "storage_error",
					"A stored photo could not be deleted, so the company was not deleted. Try again.")
				return
			}
		}
	}
	_, brokerUsers, err := s.Store.DeleteClient(r.Context(), clientID)
	if err != nil {
		s.serverError(w, "delete client", err)
		return
	}
	if s.Broker != nil {
		for _, u := range brokerUsers {
			if err := s.Broker.DeleteSite(r.Context(), u); err != nil {
				// The rows are gone and the login cannot publish anywhere the
				// server will accept (ingest resolves the site and finds none),
				// so this is a leftover to tidy, not a failure to report as one.
				s.logf("delete client %s: broker login %s not removed: %v", row.Slug, u, err)
			}
		}
	}
	s.Store.Audit(r.Context(), AuditEntry{
		ActorID: p.UserID, ActorKind: "user", Action: "client.deleted",
		Entity: "client", EntityID: clientID,
		Detail: map[string]any{"slug": row.Slug, "images_deleted": len(keys), "broker_logins": brokerUsers},
	})
	s.logf("WARNING company %s deleted by %s: %d images, %d broker logins", row.Slug, p.UserID, len(keys), len(brokerUsers))
	writeJSON(w, http.StatusOK, map[string]any{"deleted": row.Slug, "images_deleted": len(keys)})
}

// DELETE /api/sites/{site} - an owner removes a shop opened by mistake.
//
// Only a shop with no visits and no cameras. A shop with history holds the
// tenant's footfall and, through its visits, faces; taking that away is an
// erasure decision, not a tidy-up, and there is no endpoint for it yet.
func (s *Server) handleDeleteSite(w http.ResponseWriter, r *http.Request) {
	p := PrincipalFrom(r.Context())
	if p.Role != "owner" || p.ClientID == "" {
		writeErr(w, http.StatusForbidden, "forbidden", "Only the owner can remove a shop.")
		return
	}
	site, ok := s.resolveSite(w, r, r.PathValue("site"))
	if !ok {
		return
	}
	username, err := s.Store.DeleteEmptySite(r.Context(), p.ClientID, site)
	if err != nil {
		if errors.Is(err, ErrSiteInUse) {
			writeErr(w, http.StatusConflict, "in_use",
				"This shop has cameras or visits, so it cannot simply be removed. Remove its cameras first; a shop with visit history is kept.")
			return
		}
		if errors.Is(err, pgx.ErrNoRows) {
			writeErr(w, http.StatusNotFound, "not_found", "No such shop.")
			return
		}
		s.serverError(w, "delete site", err)
		return
	}
	if s.Broker != nil && username != "" {
		if err := s.Broker.DeleteSite(r.Context(), username); err != nil {
			s.logf("delete site %s: broker login %s not removed: %v", site, username, err)
		}
	}
	s.Store.Audit(r.Context(), AuditEntry{
		ClientID: p.ClientID, ActorID: p.UserID, ActorKind: "user",
		Action: "site.deleted", Entity: "site", EntityID: site,
	})
	w.WriteHeader(http.StatusNoContent)
}

// ErrSiteInUse is returned by DeleteEmptySite for a shop that has anything
// under it.
var ErrSiteInUse = errors.New("site has cameras or visits")

// PATCH /api/sites/{site} - rename a shop or change its timezone. Owner or
// manager. The slug is not in the body and would be refused by the database
// if it were: it is what the shop PC calls itself and a segment of the broker
// topic, and renaming it would orphan both.
func (s *Server) handleUpdateSite(w http.ResponseWriter, r *http.Request) {
	p := PrincipalFrom(r.Context())
	if !p.CanManageSites() || p.ClientID == "" {
		writeErr(w, http.StatusForbidden, "forbidden", "Only a manager or the owner can change a shop.")
		return
	}
	site, ok := s.resolveSite(w, r, r.PathValue("site"))
	if !ok {
		return
	}
	var in SiteUpdate
	if err := decode(w, r, &in); err != nil {
		badRequest(w, err.Error())
		return
	}
	if in.Name != nil {
		n := clip(trim(*in.Name), 120)
		if n == "" {
			badRequest(w, "The shop needs a name.")
			return
		}
		in.Name = &n
	}
	if in.Timezone != nil {
		if _, err := time.LoadLocation(strings.TrimSpace(*in.Timezone)); err != nil {
			badRequest(w, "Unknown timezone. Use an IANA name such as Asia/Kolkata.")
			return
		}
	}
	if in.Name == nil && in.Timezone == nil {
		badRequest(w, "Nothing to change: give a name or a timezone.")
		return
	}
	out, err := s.Store.UpdateSite(r.Context(), p.ClientID, site, in)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			writeErr(w, http.StatusNotFound, "not_found", "No such shop.")
			return
		}
		s.serverError(w, "update site", err)
		return
	}
	s.Store.Audit(r.Context(), AuditEntry{
		ClientID: p.ClientID, ActorID: p.UserID, ActorKind: "user",
		Action: "site.updated", Entity: "site", EntityID: site,
		Detail: map[string]any{"name": out.Name, "timezone": out.Timezone},
	})
	writeJSON(w, http.StatusOK, out)
}