package api

import (
	"context"
	"net/http"
	"strings"

	"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"`
	PrimaryParent *string `json:"primary_parent,omitempty" jsonschema:"records only: the primary category of the breadcrumb trail and the article section, one of the record's parents as <type>:<id> (seo_get_url_seo and the graph tool name them); empty for the first parent. Shared by every locale"`
	Schema        *string `json:"schema,omitempty" jsonschema:"records only: the structured data as a JSON string {\"type\": schema type or empty for the default, \"fields\": {serviceType, areaServed, price, currency} for Service, \"custom\": custom JSON-LD text (an object or a list, at most 16 KB, no script tag; a node with a generated @id is merged into it)}; empty resets it. Shared by every locale"`
}

// 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,
		"primary_parent": v.PrimaryParent, "schema": v.Schema,
	} {
		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, one of the record's locales (422 locale_unknown otherwise); 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
	})
}

// GetSEOInput is the query of GET /_seo/api/v1/seo.
type GetSEOInput struct {
	URL string `json:"url" query:"url" jsonschema:"the page: a path such as /blog/post or an absolute URL of the site"`
}

// GetSEO serves GET /_seo/api/v1/seo?url= (D-13): the effective SEO of a
// URL with the source of every value (rule, record, template, global,
// content or default), the redirect decision (action redirect or gone with
// the location), the owner a change would be written to, and the P1
// warnings (a URL rule overriding the record, a canonical that redirects
// or points to a noindex page). 422 for a URL that is not a path or
// http(s) URL.
func GetSEO(service func() *classes.Service) http.HandlerFunc {
	return manage(service, func(ctx context.Context, svc *classes.Service, r *http.Request) (int, any, error) {
		target := r.URL.Query().Get("url")
		res, err := svc.Resolver().Resolve(ctx, target)
		if err != nil {
			return 0, nil, err
		}
		db, err := read(ctx, svc)
		if err != nil {
			return 0, nil, err
		}
		owner, _, err := svc.FindOwner(ctx, db, target, false)
		if err != nil {
			return 0, nil, err
		}
		var status classes.StatusView
		switch {
		case owner.WrittenTo == classes.WrittenToRecord:
			if status, err = svc.RecordStatus(ctx, owner.Type, owner.ID); err != nil {
				return 0, nil, err
			}
		case owner.RuleID != 0:
			rule, err := classes.LoadRule(db, owner.RuleID)
			if err != nil {
				return 0, nil, err
			}
			status = svc.RuleStatus(ctx, rule)
		}
		warnings := []string{}
		for _, c := range status.Callouts {
			text := strings.TrimSpace(c.Title + " " + c.Text)
			warnings = append(warnings, text)
		}
		sources := res.Sources
		if sources == nil {
			sources = map[string]string{}
		}
		return http.StatusOK, map[string]any{
			"url":      res.URL,
			"action":   res.Action,
			"status":   res.Status,
			"location": res.Location,
			"locale":   res.Locale,
			"staging":  res.Staging,
			"seo":      res.SEO,
			"sources":  sources,
			"owner":    owner,
			"warnings": warnings,
		}, nil
	})
}