package web

// The search page (novox/hq ADR 0440 §4, issue 1265): the form's own field names are exactly mail-store.search's
// own argument names (mesh-mail tools.go searchArgs, issue 1232), so a filled field maps straight onto the
// seat's own argument of the same name; an empty field is left out of the call entirely, never sent as "".
// Paged by date exactly as the folder page (issue 1264): 50 a page, the next link asking again with before the
// last shown mail's own date.

import (
	"context"
	"encoding/json"
	"html/template"
	"net/http"
	"strings"
	"time"
)

var searchTemplate = template.Must(template.New("search").Parse(`<!DOCTYPE html>
<html><head><title>Search mail</title></head><body>
<h1>Search</h1>
<form method="get" action="/search">
<input type="text" name="query" placeholder="words" value="{{.Query}}">
<input type="text" name="from" placeholder="from" value="{{.From}}">
<input type="text" name="to" placeholder="to" value="{{.To}}">
<input type="text" name="on-or-after" placeholder="on or after" value="{{.OnOrAfter}}">
<input type="text" name="before" placeholder="before" value="{{.Before}}">
<label><input type="checkbox" name="has-attachment" value="on"{{if .HasAttachment}} checked{{end}}> has attachment</label>
<button type="submit">Search</button>
</form>
{{if .Error}}<p>{{.Error}}</p>{{else}}
<ul>
{{range .Mails}}<li>{{.Date}} — {{range .From}}{{.Name}} &lt;{{.Address}}&gt; {{end}}— <a href="/mail?account={{.Account}}&amp;folder={{.Folder}}&amp;uid={{.UID}}">{{.Subject}}</a></li>{{end}}
</ul>
{{if .NextBefore}}<p><a href="{{.NextLink}}">Older</a></p>{{end}}
{{end}}
</body></html>`))

type searchTemplateData struct {
	Query, From, To, OnOrAfter, Before, Error, NextBefore, NextLink string
	HasAttachment                                                   bool
	Mails                                                           []searchResult
}

// searchArgsFromForm builds mail-store.search's own arguments from the request's query parameters: a field
// left empty is left out of the call entirely (issue 1265/AC1) — never sent empty. "from" is split into a list
// on whitespace or commas, mail-store.search's own array argument. limit is always MostFolderResults (AC2),
// mechanical paging the form itself never carries.
func searchArgsFromForm(q map[string][]string) map[string]any {
	get := func(name string) string {
		if v, ok := q[name]; ok && len(v) > 0 {
			return strings.TrimSpace(v[0])
		}
		return ""
	}
	args := map[string]any{"limit": float64(MostFolderResults)}
	if v := get("query"); v != "" {
		args["query"] = v
	}
	if v := get("from"); v != "" {
		var list []string
		for _, part := range strings.FieldsFunc(v, func(r rune) bool { return r == ',' || r == ' ' }) {
			if part != "" {
				list = append(list, part)
			}
		}
		if len(list) > 0 {
			args["from"] = list
		}
	}
	if v := get("to"); v != "" {
		args["to"] = v
	}
	if v := get("on-or-after"); v != "" {
		args["on-or-after"] = v
	}
	if v := get("before"); v != "" {
		args["before"] = v
	}
	if v := get("has-attachment"); v != "" {
		args["has-attachment"] = true
	}
	return args
}

// searchPage is issue 1265/AC1-AC4.
func (b *Bundle) searchPage(w http.ResponseWriter, r *http.Request) {
	q := r.URL.Query()
	data := searchTemplateData{
		Query: q.Get("query"), From: q.Get("from"), To: q.Get("to"),
		OnOrAfter: q.Get("on-or-after"), Before: q.Get("before"), HasAttachment: q.Get("has-attachment") != "",
	}
	args := searchArgsFromForm(q)
	ctx, cancel := context.WithTimeout(r.Context(), 20*time.Second)
	defer cancel()
	raw, err := b.searchAsk(ctx, args)
	if err != nil {
		data.Error = "the search could not be answered"
		renderPage(w, searchTemplate, data)
		return
	}
	var answer searchAnswer
	if err := json.Unmarshal(raw, &answer); err != nil {
		data.Error = "the search could not be answered"
		renderPage(w, searchTemplate, data)
		return
	}
	data.Mails = answer.Found
	if len(answer.Found) >= MostFolderResults {
		last := answer.Found[len(answer.Found)-1].Date
		data.NextBefore = last
		next := r.URL.Query()
		next.Set("before", last)
		data.NextLink = "/search?" + next.Encode()
	}
	renderPage(w, searchTemplate, data)
}