package api

import (
	"context"
	"net/http"

	"git.golem15.com/golem15/sm-seo-plugin/classes"
	"gorm.io/gorm"
)

// SEOValues are the SEO values of a URL in a request: a value that is
// absent is left as it is, an empty one inherits.
type SEOValues struct {
	Title         *string `json:"title,omitempty" jsonschema:"the SEO title"`
	Description   *string `json:"description,omitempty" jsonschema:"the meta description"`
	Keyphrase     *string `json:"keyphrase,omitempty" jsonschema:"the focus keyphrase (records only)"`
	Canonical     *string `json:"canonical,omitempty" jsonschema:"the canonical URL: a path or an absolute http(s) URL"`
	Robots        *string `json:"robots,omitempty" jsonschema:"robots directives, for example noindex,follow"`
	OGTitle       *string `json:"og_title,omitempty" jsonschema:"the social title"`
	OGDescription *string `json:"og_description,omitempty" jsonschema:"the social description"`
	OGImage       *string `json:"og_image,omitempty" jsonschema:"the social image: a path or an absolute URL"`
}

// Map returns the values that are set, keyed by column.
func (v SEOValues) Map() map[string]string {
	out := map[string]string{}
	for column, p := range map[string]*string{
		"title": v.Title, "description": v.Description, "keyphrase": v.Keyphrase,
		"canonical": v.Canonical, "robots": v.Robots, "og_title": v.OGTitle,
		"og_description": v.OGDescription, "og_image": v.OGImage,
	} {
		if p != nil {
			out[column] = *p
		}
	}
	return out
}

// SetSEOInput is the body of PUT /_seo/api/v1/seo.
type SetSEOInput struct {
	URL       string    `json:"url" jsonschema:"the page: a path such as /blog/post or an absolute URL of the site"`
	Locale    string    `json:"locale,omitempty" jsonschema:"the locale of a record's SEO; the locale the URL matches when omitted"`
	Values    SEOValues `json:"values" jsonschema:"the values to change"`
	ForceRule bool      `json:"force_rule,omitempty" jsonschema:"write a URL rule even when a record is behind the URL"`
}

// SetSEO serves PUT /_seo/api/v1/seo (D-11, P-25): the values go to the
// record behind the URL in its locale, else to an exact URL rule (created
// when missing), or to a rule when force_rule is set. It answers 200 with
// where the change was written ({"written_to":"record"|"rule", "type",
// "id", "locale", "rule_id"}) and the stored values; 422 for a URL that is
// not a path or http(s) URL or for invalid values. History records the
// write with via mcp when it comes through MCP.
func SetSEO(service func() *classes.Service) http.HandlerFunc {
	return manage(service, func(ctx context.Context, svc *classes.Service, r *http.Request) (int, any, error) {
		var in SetSEOInput
		if err := decode(r, maxBody, &in); err != nil {
			return 0, nil, err
		}
		var res classes.URLSEOResult
		err := write(ctx, svc, func(ctx context.Context, tx *gorm.DB) error {
			var err error
			res, err = svc.SetURLSEO(ctx, tx, classes.URLSEOWrite{URL: in.URL, Locale: in.Locale, Values: in.Values.Map(), ForceRule: in.ForceRule})
			return err
		})
		if err != nil {
			return 0, nil, err
		}
		return http.StatusOK, res, nil
	})
}