package handlers

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

	"git.haelnorr.com/h/golib/hws"
	"git.haelnorr.com/h/oslstats/internal/db"
	"git.haelnorr.com/h/oslstats/internal/throw"
	"git.haelnorr.com/h/oslstats/internal/validation"
	adminview "git.haelnorr.com/h/oslstats/internal/view/adminview"
	"git.haelnorr.com/h/timefmt"
	"github.com/pkg/errors"
	"github.com/uptrace/bun"
)

// AdminAuditLogsPage renders the full admin dashboard page with audit logs section (GET request)
func AdminAuditLogsPage(s *hws.Server, conn *db.DB) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		pageOpts, ok := db.GetPageOpts(s, w, r)
		if !ok {
			return
		}

		var logs *db.List[db.AuditLog]
		var users []*db.User
		var actions []string
		var resourceTypes []string

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error

			// Get filters from query
			filters, ok := getAuditFiltersFromQuery(s, w, r)
			if !ok {
				return false, nil
			}

			// Get audit logs
			logs, err = db.GetAuditLogs(ctx, tx, pageOpts, filters)
			if err != nil {
				return false, errors.Wrap(err, "db.GetAuditLogs")
			}

			// Get all users for filter dropdown
			usersList, err := db.GetUsers(ctx, tx, nil)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUsers")
			}
			users = usersList.Items

			// Get unique actions
			actions, err = db.GetUniqueActions(ctx, tx)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUniqueActions")
			}

			// Get unique resource types
			resourceTypes, err = db.GetUniqueResourceTypes(ctx, tx)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUniqueResourceTypes")
			}

			return true, nil
		}); !ok {
			return
		}

		renderSafely(adminview.AuditLogsPage(logs, users, actions, resourceTypes), s, r, w)
	})
}

// AdminAuditLogsList shows the full audit logs list with filters (POST request for HTMX)
func AdminAuditLogsList(s *hws.Server, conn *db.DB) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		pageOpts, ok := db.GetPageOpts(s, w, r)
		if !ok {
			return
		}

		var logs *db.List[db.AuditLog]
		var users []*db.User
		var actions []string
		var resourceTypes []string

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error

			// Get filters from form
			filters, ok := getAuditFiltersFromForm(s, w, r)
			if !ok {
				return false, nil
			}

			// Get audit logs
			logs, err = db.GetAuditLogs(ctx, tx, pageOpts, filters)
			if err != nil {
				return false, errors.Wrap(err, "db.GetAuditLogs")
			}

			// Get all users for filter dropdown
			usersList, err := db.GetUsers(ctx, tx, nil)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUsers")
			}
			users = usersList.Items

			// Get unique actions
			actions, err = db.GetUniqueActions(ctx, tx)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUniqueActions")
			}

			// Get unique resource types
			resourceTypes, err = db.GetUniqueResourceTypes(ctx, tx)
			if err != nil {
				return false, errors.Wrap(err, "db.GetUniqueResourceTypes")
			}

			return true, nil
		}); !ok {
			return
		}

		renderSafely(adminview.AuditLogsList(logs, users, actions, resourceTypes), s, r, w)
	})
}

// AdminAuditLogsFilter returns only the results container (table + pagination) for HTMX updates
func AdminAuditLogsFilter(s *hws.Server, conn *db.DB) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		pageOpts, ok := db.GetPageOpts(s, w, r)
		if !ok {
			return
		}

		var logs *db.List[db.AuditLog]

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error

			// Get filters from form
			filters, ok := getAuditFiltersFromForm(s, w, r)
			if !ok {
				return false, nil
			}

			// Get audit logs
			logs, err = db.GetAuditLogs(ctx, tx, pageOpts, filters)
			if err != nil {
				return false, errors.Wrap(err, "db.GetAuditLogs")
			}

			return true, nil
		}); !ok {
			return
		}

		// Return only the results container, not the full page with filters
		renderSafely(adminview.AuditLogsResults(logs), s, r, w)
	})
}

// AdminAuditLogDetail shows details for a single audit log entry
func AdminAuditLogDetail(s *hws.Server, conn *db.DB) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Get ID from path
		idStr := r.PathValue("id")
		if idStr == "" {
			throw.BadRequest(s, w, r, "Missing audit log ID", nil)
			return
		}

		id, err := strconv.Atoi(idStr)
		if err != nil {
			throw.BadRequest(s, w, r, "Invalid audit log ID", err)
			return
		}

		var log *db.AuditLog

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error
			log, err = db.GetAuditLogByID(ctx, tx, id)
			if err != nil {
				if db.IsBadRequest(err) {
					throw.NotFound(s, w, r, r.URL.Path)
					return false, nil
				}
				return false, errors.Wrap(err, "db.GetAuditLogByID")
			}
			return true, nil
		}); !ok {
			return
		}

		renderSafely(adminview.AuditLogDetail(log), s, r, w)
	})
}

// getAuditFiltersFromQuery extracts audit log filters from query string
func getAuditFiltersFromQuery(s *hws.Server, w http.ResponseWriter, r *http.Request) (*db.AuditLogFilter, bool) {
	g := validation.NewQueryGetter(r)
	filters, ok := buildAuditFilters(g, s, w, r)
	return filters, ok
}

// getAuditFiltersFromForm extracts audit log filters from form data
func getAuditFiltersFromForm(s *hws.Server, w http.ResponseWriter, r *http.Request) (*db.AuditLogFilter, bool) {
	g, ok := validation.ParseFormOrError(s, w, r)
	if !ok {
		return nil, false
	}
	return buildAuditFilters(g, s, w, r)
}

// buildAuditFilters builds audit log filters from a validation.Getter
func buildAuditFilters(g validation.Getter, s *hws.Server, w http.ResponseWriter, r *http.Request) (*db.AuditLogFilter, bool) {
	filters := db.NewAuditLogFilter()

	userIDs := g.IntList("user_id").Values()
	actions := g.StringList("action").Values()
	resourceTypes := g.StringList("resource_type").Values()
	results := g.StringList("result").Values()
	format := timefmt.NewBuilder().DayNumeric2().Slash().
		MonthNumeric2().Slash().Year4().Build()
	startDate := g.Time("start_date", format).Optional().Value
	endDate := g.Time("end_date", format).Optional().Value

	if !g.ValidateAndError(s, w, r) {
		return nil, false
	}

	if len(userIDs) > 0 {
		filters.UserIDs(userIDs)
	}
	if len(actions) > 0 {
		filters.Actions(actions)
	}
	if len(resourceTypes) > 0 {
		filters.ResourceTypes(resourceTypes)
	}
	if len(results) > 0 {
		filters.Results(results)
	}

	if !startDate.IsZero() {
		filters.DateRange(startDate.Unix(), 0)
	}
	if !endDate.IsZero() {
		endOfDay := endDate.Add(23*time.Hour + 59*time.Minute + 59*time.Second)
		filters.DateRange(0, endOfDay.Unix())
	}

	return filters, true
}