package api_impl

import (
	"context"
	"database/sql"
	"log/slog"
	"net/http"

	"atlas9.dev/c/core/dbi"
	"atlas9.dev/c/core/iam"
	"atlas9.dev/c/demo/api"
	"atlas9.dev/c/demo/lib"
	"atlas9.dev/c/demo/lib/access"
)

type AuditImpl struct {
	DB    *sql.DB
	Guard access.Guard
	Audit dbi.Factory[iam.AuditStore]
}

func (s *AuditImpl) ServeMux(mux *http.ServeMux) {
	mux.HandleFunc(api.Path_Audit_List, s.List)
	mux.HandleFunc(api.Path_Audit_ListByUser, s.ListByUser)
}

func (s *AuditImpl) List(w http.ResponseWriter, r *http.Request) {

	// Read and validate the request body
	var req api.Audit_ListReq
	if read(w, r, &req) {
		return
	}

	// Check access
	if check(w, r, s.Guard, iam.CapAuditRead, req.Tenant, "") {
		return
	}

	// Load the data from the database
	ctx := r.Context()
	var res api.Audit_ListRes
	err := dbi.ReadOnly(ctx, s.DB, func(tx dbi.DBI) error {
		return s.Audit(tx).List(ctx, req.Tenant, req.Page, &res.Page)
	})

	write(ctx, w, err, res)
}

func (s *AuditImpl) ListByUser(w http.ResponseWriter, r *http.Request) {

	// Read and validate the request body
	var req api.Audit_ListByUserReq
	if read(w, r, &req) {
		return
	}

	// Reading your own trail is always allowed; reading another user's
	// requires system access. The store enforces this.

	// Load the data from the database
	ctx := r.Context()
	var res api.Audit_ListByUserRes
	err := dbi.ReadOnly(ctx, s.DB, func(tx dbi.DBI) error {
		return s.Audit(tx).ListByUser(ctx, req.UserID, req.Page, &res.Page)
	})

	write(ctx, w, err, res)
}

// audit appends an audit entry within the caller's transaction, filling
// Actor and Request from the request context. Call it after the mutation
// succeeds, inside the same dbi.ReadWrite closure, so the entry commits
// and rolls back with the change it describes.
//
// A pre-set Actor is preserved, for flows where the acting user is known
// but not yet an authenticated principal (login).
func audit(ctx context.Context, s iam.AuditStore, e iam.AuditEntry) error {

	if e.Actor == "" {
		e.Actor = iam.GetPrincipal(ctx).Subject
	}
	e.Request = lib.GetRequestID(ctx)
	if err := s.Append(ctx, &e); err != nil {
		return err
	}
	slog.DebugContext(ctx, "audit recorded", "action", e.Action, "resource", e.Resource)
	return nil
}