package api

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

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

// ListIssuesInput is the query of GET /_seo/api/v1/issues.
type ListIssuesInput struct {
	Kind     string `json:"kind,omitempty" query:"kind" jsonschema:"one kind only, e.g. h1_multiple, broken_link, missing_title, content_js, orphan_page, redirect_chain or sitemap_blocked"`
	Severity string `json:"severity,omitempty" query:"severity" jsonschema:"error, warning or notice"`
	Source   string `json:"source,omitempty" query:"source" jsonschema:"crawl (found by the crawler) or cms (CMS data checks)"`
	Fix      string `json:"fix,omitempty" query:"fix" jsonschema:"tool (fixable through the MCP tool the issue names) or code (needs a change in the site's templates)"`
	Status   string `json:"status,omitempty" query:"status" jsonschema:"open (the default), ignored or all"`
	URL      string `json:"url,omitempty" query:"url" jsonschema:"only issues of this address (a path such as /blog/post)"`
	Crawl    uint   `json:"crawl,omitempty" query:"crawl" jsonschema:"the issues of this crawl id instead of the current ones"`
}

// IssueIDInput names one issue.
type IssueIDInput struct {
	ID uint `json:"id" path:"id" jsonschema:"the issue id"`
}

// IssueIDsInput is the body of the ignore and unignore calls.
type IssueIDsInput struct {
	IDs []uint `json:"ids" jsonschema:"the issue ids"`
}

// IssueView is a stored issue in an answer: the Phase 32 keys (kind, url,
// locale, details, tool) and the audit's id, severity, source, fix,
// found_at, ignored and crawl_id. tool is the fixing MCP tool when fix is
// tool; for fix code, details.what names the template element.
type IssueView struct {
	ID       uint           `json:"id"`
	Kind     string         `json:"kind"`
	URL      string         `json:"url"`
	Locale   string         `json:"locale,omitempty"`
	Details  map[string]any `json:"details,omitempty"`
	Tool     string         `json:"tool"`
	Severity string         `json:"severity"`
	Source   string         `json:"source"`
	Fix      string         `json:"fix"`
	FoundAt  *time.Time     `json:"found_at"`
	Ignored  bool           `json:"ignored"`
	CrawlID  *uint          `json:"crawl_id"`
}

// issueViews turns stored issues into their answer form.
func issueViews(db *gorm.DB, rows []models.Issue) ([]IssueView, error) {
	fps := make([]string, 0, len(rows))
	for _, r := range rows {
		fps = append(fps, r.Fingerprint)
	}
	ignored, err := crawl.IgnoredSet(db, fps)
	if err != nil {
		return nil, err
	}
	out := make([]IssueView, 0, len(rows))
	for _, r := range rows {
		out = append(out, IssueView{
			ID: r.ID, Kind: r.Kind, URL: r.URL, Locale: r.Locale, Details: r.DetailsMap(), Tool: r.Tool,
			Severity: r.Severity, Source: r.Source, Fix: r.Fix, FoundAt: r.FoundAt,
			Ignored: ignored[r.Fingerprint], CrawlID: r.CrawlID,
		})
	}
	return out, nil
}

// ListIssues serves GET /_seo/api/v1/issues (D-13, D-14): the audit's
// current issues, errors first: the newest crawl's findings with the
// CMS-data issues stored with it, or before any crawl the CMS-data issues
// as they are now (crawl selects another crawl's). Each issue names the
// tool that fixes it, or fix code. The filters are severity, kind,
// source, fix, url and status (open by default: ignored issues are left
// out; ignored or all). counts holds the number per kind before the kind
// filter.
func ListIssues(service func() *classes.Service) http.HandlerFunc {
	return manage(service, func(ctx context.Context, svc *classes.Service, r *http.Request) (int, any, error) {
		db, err := read(ctx, svc)
		if err != nil {
			return 0, nil, err
		}
		latest, err := crawl.Current(ctx, svc, db)
		if err != nil {
			return 0, nil, err
		}
		q := r.URL.Query()
		base := crawl.CurrentScope(db.Model(&models.Issue{}), latest)
		if id, err := strconv.ParseUint(strings.TrimSpace(q.Get("crawl")), 10, 64); err == nil && id > 0 {
			base = db.Model(&models.Issue{}).Where("golem15_seo_issues.crawl_id = ?", id)
		}
		var all []models.Issue
		if err := base.Order("rank ASC, kind ASC, url ASC, id ASC").Find(&all).Error; err != nil {
			return 0, nil, err
		}
		views, err := issueViews(db, all)
		if err != nil {
			return 0, nil, err
		}
		status := strings.TrimSpace(q.Get("status"))
		if status == "" {
			status = models.IssueOpen
		}
		match := map[string]string{
			"kind": strings.TrimSpace(q.Get("kind")), "severity": strings.TrimSpace(q.Get("severity")),
			"source": strings.TrimSpace(q.Get("source")), "fix": strings.TrimSpace(q.Get("fix")),
			"url": strings.TrimSpace(q.Get("url")),
		}
		counts := map[string]int{}
		out := make([]IssueView, 0, len(views))
		for _, v := range views {
			if status == models.IssueOpen && v.Ignored || status == models.IssueIgnored && !v.Ignored {
				continue
			}
			if !matches(match["severity"], v.Severity) || !matches(match["source"], v.Source) || !matches(match["fix"], v.Fix) || !matches(match["url"], v.URL) {
				continue
			}
			counts[v.Kind]++
			if matches(match["kind"], v.Kind) {
				out = append(out, v)
			}
		}
		return http.StatusOK, map[string]any{"data": out, "counts": counts, "total": len(out)}, nil
	})
}

// matches reports whether a filter value (empty: any) matches.
func matches(filter, value string) bool { return filter == "" || filter == value }

// RecheckIssue serves POST /_seo/api/v1/issues/{id}/recheck: the issue's
// address is fetched again through the crawler client and its issues are
// replaced; the answer has the address, the issues left and the message.
func RecheckIssue(service func() *classes.Service) http.HandlerFunc {
	return manage(service, func(ctx context.Context, svc *classes.Service, r *http.Request) (int, any, error) {
		id, err := pathID(r, "id")
		if err != nil {
			return 0, nil, err
		}
		var res crawl.RecheckResult
		err = write(ctx, svc, func(ctx context.Context, tx *gorm.DB) error {
			issue, err := crawl.LoadIssue(tx, id)
			if err != nil {
				return err
			}
			res, err = crawl.Recheck(ctx, svc, tx, issue)
			return err
		})
		if errors.Is(err, crawl.ErrNoSiteURL) {
			return 0, nil, StartRefusal(ctx, svc, err)
		}
		if err != nil {
			return 0, nil, err
		}
		msg := svc.PhraseCtx(ctx, "golem15.seo::lang.issues.recheck_fixed", nil)
		if res.Remaining > 0 {
			msg = svc.ChoiceCtx(ctx, "golem15.seo::lang.issues.rechecked", res.Remaining, nil)
		}
		return http.StatusOK, map[string]any{"url": res.URL, "remaining": res.Remaining, "message": msg}, nil
	})
}

// IgnoreIssues serves POST /_seo/api/v1/issues/ignore: the issues are
// hidden in this and later crawls until they are no longer ignored.
func IgnoreIssues(service func() *classes.Service) http.HandlerFunc {
	return ignoreHandler(service, true)
}

// UnignoreIssues serves POST /_seo/api/v1/issues/unignore: the issues are
// shown in the audit again.
func UnignoreIssues(service func() *classes.Service) http.HandlerFunc {
	return ignoreHandler(service, false)
}

func ignoreHandler(service func() *classes.Service, ignore bool) http.HandlerFunc {
	return manage(service, func(ctx context.Context, svc *classes.Service, r *http.Request) (int, any, error) {
		var in IssueIDsInput
		if err := decode(r, maxBody, &in); err != nil {
			return 0, nil, err
		}
		if len(in.IDs) == 0 || len(in.IDs) > 1000 {
			return 0, nil, Fail(http.StatusUnprocessableEntity, "ids_invalid")
		}
		n := 0
		err := write(ctx, svc, func(ctx context.Context, tx *gorm.DB) error {
			var rows []models.Issue
			if err := tx.Where("id IN ?", in.IDs).Find(&rows).Error; err != nil {
				return err
			}
			if len(rows) != len(uniqueIDs(in.IDs)) {
				return gorm.ErrRecordNotFound
			}
			var err error
			if ignore {
				adminID, _, _ := svc.Actor(ctx, tx)
				n, err = crawl.Ignore(tx, rows, adminID)
			} else {
				n, err = crawl.Unignore(tx, rows)
			}
			return err
		})
		if err != nil {
			return 0, nil, err
		}
		key, field := "golem15.seo::lang.issues.unignored", "unignored"
		if ignore {
			key, field = "golem15.seo::lang.issues.ignored", "ignored"
		}
		return http.StatusOK, map[string]any{field: n, "message": svc.ChoiceCtx(ctx, key, n, nil)}, nil
	})
}

// uniqueIDs drops repeated ids.
func uniqueIDs(ids []uint) []uint {
	seen := map[uint]bool{}
	var out []uint
	for _, id := range ids {
		if !seen[id] {
			seen[id] = true
			out = append(out, id)
		}
	}
	return out
}