// Copyright (c) 2026 Probo Inc <hello@probo.com>.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package drivers

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"go.probo.inc/probo/pkg/coredata"
)

type MetabaseDriver struct {
	httpClient  *http.Client
	instanceURL string
}

var _ Driver = (*MetabaseDriver)(nil)

type metabaseUser struct {
	ID          int    `json:"id"`
	Email       string `json:"email"`
	FirstName   string `json:"first_name"`
	LastName    string `json:"last_name"`
	CommonName  string `json:"common_name"`
	IsActive    bool   `json:"is_active"`
	IsSuperuser bool   `json:"is_superuser"`
	LastLogin   string `json:"last_login"`
	DateJoined  string `json:"date_joined"`
}

type metabaseUsersResponse struct {
	Data   []metabaseUser `json:"data"`
	Total  int            `json:"total"`
	Limit  *int           `json:"limit"`
	Offset *int           `json:"offset"`
}

const metabaseUsersPageLimit = 50

func NewMetabaseDriver(httpClient *http.Client, instanceURL string) *MetabaseDriver {
	return &MetabaseDriver{
		httpClient:  httpClient,
		instanceURL: instanceURL,
	}
}

func (d *MetabaseDriver) ListAccounts(ctx context.Context) ([]AccountRecord, error) {
	users, err := d.queryUsers(ctx)
	if err != nil {
		return nil, err
	}

	records := make([]AccountRecord, 0, len(users))

	for _, u := range users {
		if u.Email == "" {
			continue
		}

		record := AccountRecord{
			Email:       u.Email,
			FullName:    metabaseFullName(u),
			Roles:       metabaseRoles(u.IsSuperuser),
			Active:      new(u.IsActive),
			IsAdmin:     u.IsSuperuser,
			ExternalID:  strconv.Itoa(u.ID),
			MFAStatus:   coredata.MFAStatusUnknown,
			AuthMethod:  coredata.AccessReviewEntryAuthMethodUnknown,
			AccountType: coredata.AccessReviewEntryAccountTypeUser,
		}

		if t, ok := parseMetabaseTimestamp(u.LastLogin); ok {
			record.LastLogin = &t
		}

		if t, ok := parseMetabaseTimestamp(u.DateJoined); ok {
			record.CreatedAt = &t
		}

		records = append(records, record)
	}

	return records, nil
}

func (d *MetabaseDriver) queryUsers(ctx context.Context) ([]metabaseUser, error) {
	baseURL, err := url.Parse(d.instanceURL)
	if err != nil {
		return nil, fmt.Errorf("cannot parse metabase instance url: %w", err)
	}

	var users []metabaseUser

	offset := 0

	for {
		page, err := d.queryUsersPage(ctx, baseURL, offset)
		if err != nil {
			return nil, err
		}

		users = append(users, page.Data...)

		offset += len(page.Data)
		if len(page.Data) == 0 || offset >= page.Total {
			break
		}
	}

	return users, nil
}

func (d *MetabaseDriver) queryUsersPage(
	ctx context.Context,
	baseURL *url.URL,
	offset int,
) (*metabaseUsersResponse, error) {
	endpoint := baseURL.JoinPath("api", "user")
	q := endpoint.Query()
	q.Set("status", "all")
	q.Set("limit", strconv.Itoa(metabaseUsersPageLimit))
	q.Set("offset", strconv.Itoa(offset))
	endpoint.RawQuery = q.Encode()

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint.String(), nil)
	if err != nil {
		return nil, fmt.Errorf("cannot create metabase users request: %w", err)
	}

	req.Header.Set("Accept", "application/json")

	httpResp, err := d.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("cannot execute metabase users request: %w", err)
	}

	defer func() {
		_ = httpResp.Body.Close()
	}()

	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
		return nil, fmt.Errorf("cannot fetch metabase users: unexpected status %d", httpResp.StatusCode)
	}

	var resp metabaseUsersResponse
	if err := json.NewDecoder(httpResp.Body).Decode(&resp); err != nil {
		return nil, fmt.Errorf("cannot decode metabase users response: %w", err)
	}

	return &resp, nil
}

func metabaseFullName(u metabaseUser) string {
	if u.CommonName != "" {
		return u.CommonName
	}

	return strings.TrimSpace(strings.Join([]string{u.FirstName, u.LastName}, " "))
}

func metabaseRoles(isSuperuser bool) []string {
	if isSuperuser {
		return []string{"Admin"}
	}

	return []string{"User"}
}

// metabaseNameResolver resolves the Metabase site name by querying
// /api/session/properties on the configured Metabase instance, which
// exposes the site-name setting to any authenticated session.
type metabaseNameResolver struct {
	httpClient  *http.Client
	instanceURL string
}

var _ NameResolver = (*metabaseNameResolver)(nil)

type metabaseSessionProperties struct {
	SiteName string `json:"site-name"`
}

func NewMetabaseNameResolver(httpClient *http.Client, instanceURL string) NameResolver {
	return &metabaseNameResolver{
		httpClient:  httpClient,
		instanceURL: instanceURL,
	}
}

func (r *metabaseNameResolver) ResolveInstanceName(ctx context.Context) (string, error) {
	baseURL, err := url.Parse(r.instanceURL)
	if err != nil {
		return "", fmt.Errorf("cannot parse metabase instance url: %w", err)
	}

	endpoint := baseURL.JoinPath("api", "session", "properties")

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint.String(), nil)
	if err != nil {
		return "", fmt.Errorf("cannot create metabase session properties request: %w", err)
	}

	req.Header.Set("Accept", "application/json")

	httpResp, err := r.httpClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("cannot execute metabase session properties request: %w", err)
	}

	defer func() {
		_ = httpResp.Body.Close()
	}()

	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
		return "", nameStatusError("metabase session properties", httpResp.StatusCode)
	}

	var props metabaseSessionProperties
	if err := json.NewDecoder(httpResp.Body).Decode(&props); err != nil {
		return "", fmt.Errorf("cannot decode metabase session properties response: %w", err)
	}

	return strings.TrimSpace(props.SiteName), nil
}

func parseMetabaseTimestamp(value string) (time.Time, bool) {
	if value == "" {
		return time.Time{}, false
	}

	for _, layout := range []string{
		time.RFC3339Nano,
		time.RFC3339,
	} {
		t, err := time.Parse(layout, value)
		if err == nil {
			return t, true
		}
	}

	return time.Time{}, false
}