package server

import (
	"bytes"
	"errors"
	"html/template"
	"io/fs"
	"net/http/httptest"
	"strings"
	"testing"

	"git.coopcloud.tech/wiki-cafe/member-console/internal/config"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/embeds"
	"git.coopcloud.tech/wiki-cafe/member-console/internal/web"
)

func TestParseListParamsClamping(t *testing.T) {
	cases := []struct {
		url      string
		wantQ    string
		wantF    string
		wantPage int
	}{
		{"/operator/grants", "", "", 1},
		{"/operator/grants?q=acme&state=live&page=3", "acme", "live", 3},
		{"/operator/grants?page=abc", "", "", 1},
		{"/operator/grants?page=-4", "", "", 1},
		{"/operator/grants?page=0", "", "", 1},
	}
	for _, tc := range cases {
		r := httptest.NewRequest("GET", tc.url, nil)
		p := ParseListParams(r, "state")
		if p.Q != tc.wantQ || p.Facet != tc.wantF || p.Page != tc.wantPage {
			t.Errorf("%s: got %+v, want q=%q facet=%q page=%d", tc.url, p, tc.wantQ, tc.wantF, tc.wantPage)
		}
	}
	// A list with no facet parameter never reads one.
	r := httptest.NewRequest("GET", "/operator/persons?state=live", nil)
	if p := ParseListParams(r, ""); p.Facet != "" {
		t.Errorf("facet must stay empty when the list declares no facet param, got %q", p.Facet)
	}
}

func TestFetchPageClampsPastTheEnd(t *testing.T) {
	calls := []int32{}
	load := func(limit, offset int32) ([]string, int64, error) {
		calls = append(calls, offset)
		if offset >= 60 {
			return nil, 0, nil // past the end: no rows, and no total knowledge
		}
		return []string{"row"}, 60, nil
	}
	p := &ListParams{Page: 9}
	rows, total, err := FetchPage(p, load)
	if err != nil || len(rows) != 1 || total != 60 {
		t.Fatalf("clamped fetch: rows=%d total=%d err=%v", len(rows), total, err)
	}
	if p.Page != 1 {
		t.Errorf("page must clamp to 1 after an out-of-range fetch, got %d", p.Page)
	}
	if len(calls) != 2 || calls[1] != 0 {
		t.Errorf("expected a re-run at offset 0, calls=%v", calls)
	}

	wantErr := errors.New("boom")
	_, _, err = FetchPage(&ListParams{Page: 1}, func(_, _ int32) ([]string, int64, error) { return nil, 0, wantErr })
	if !errors.Is(err, wantErr) {
		t.Errorf("load errors must surface, got %v", err)
	}
}

func TestListNavMathAndURLs(t *testing.T) {
	n := ListNav{BasePath: "/operator/grants", FacetParam: "state", Q: "a b", Facet: "live", Page: 2, Total: 120}
	if n.Pages() != 3 || n.From() != 51 || n.To() != 100 {
		t.Errorf("math: pages=%d from=%d to=%d", n.Pages(), n.From(), n.To())
	}
	if got := n.Showing(); got != "Showing 51–100 of 120" {
		t.Errorf("Showing() = %q", got)
	}
	if !n.HasPrev() || !n.HasNext() {
		t.Error("page 2 of 3 must have both prev and next")
	}
	// URLs preserve the rest of the state and escape the term.
	if got := n.NextURL(); got != "/operator/grants?page=3&q=a+b&state=live" {
		t.Errorf("NextURL = %q", got)
	}
	if got := n.FacetURL("inactive"); got != "/operator/grants?q=a+b&state=inactive" {
		t.Errorf("FacetURL = %q", got)
	}
	if got := n.FacetURL(""); got != "/operator/grants?q=a+b" {
		t.Errorf("FacetURL clear = %q", got)
	}
	if got := n.ClearSearchURL(); got != "/operator/grants?state=live" {
		t.Errorf("ClearSearchURL = %q", got)
	}

	empty := ListNav{BasePath: "/operator/persons", Total: 0, Page: 1}
	if empty.Pages() != 1 || empty.From() != 0 || empty.To() != 0 || empty.Showing() != "" {
		t.Errorf("empty list math: pages=%d from=%d to=%d showing=%q", empty.Pages(), empty.From(), empty.To(), empty.Showing())
	}
	if empty.Filtered() {
		t.Error("empty unfiltered list must not report Filtered")
	}

	exact := ListNav{BasePath: "/x", Page: 2, Total: 100}
	if exact.Pages() != 2 || exact.To() != 100 || exact.HasNext() {
		t.Errorf("exact-multiple math: pages=%d to=%d hasNext=%v", exact.Pages(), exact.To(), exact.HasNext())
	}
}

func TestValidFacet(t *testing.T) {
	opts := []FacetOption{{Value: "live", Label: "Live"}, {Value: "inactive", Label: "Inactive"}}
	if got := ValidFacet("live", opts); got != "live" {
		t.Errorf("valid value rejected: %q", got)
	}
	if got := ValidFacet("bogus", opts); got != "" {
		t.Errorf("unknown facet value must be ignored, got %q", got)
	}
}

// listControlsTemplates builds the operator partial set the same way the
// smoke test does, so the shared list-controls defines render exactly as
// they will in handlers.
func listControlsTemplates(t *testing.T) *template.Template {
	t.Helper()
	partialsSub, err := fs.Sub(embeds.Templates, "templates/partials")
	if err != nil {
		t.Fatalf("fs.Sub partials: %v", err)
	}
	tmpl := template.New("t").Funcs(template.FuncMap{
		"renderBody":      func(string, any) (template.HTML, error) { return "", nil },
		"routeURL":        web.RouteURL,
		"fieldErr":        func(_, _, _, _ string, _, _ any) string { return "" },
		"stripeEntityURL": func(string, string) string { return "" },
		"deploymentName":  config.DeploymentName,
	})
	tmpl, err = tmpl.ParseFS(partialsSub, "operator_*.html")
	if err != nil {
		t.Fatalf("ParseFS partials: %v", err)
	}
	return tmpl
}

func renderListDefine(t *testing.T, name string, nav ListNav) string {
	t.Helper()
	var buf bytes.Buffer
	if err := listControlsTemplates(t).ExecuteTemplate(&buf, name, nav); err != nil {
		t.Fatalf("ExecuteTemplate %s: %v", name, err)
	}
	return buf.String()
}

func TestListControlsRender(t *testing.T) {
	nav := ListNav{
		BasePath:          "/operator/grants",
		SearchPlaceholder: "Search organization or product",
		FacetParam:        "state",
		FacetOptions:      []FacetOption{{Value: "live", Label: "Live"}, {Value: "inactive", Label: "Inactive"}},
		Q:                 "acme",
		Facet:             "live",
		Page:              2,
		Total:             120,
	}
	out := renderListDefine(t, "listControls", nav)
	for _, want := range []string{
		`action="/operator/grants"`,
		`name="q" value="acme"`,
		`name="state" value="live"`, // hidden input keeps the facet through a search
		`>Clear</a>`,
		`>All</a>`,
	} {
		if !strings.Contains(out, want) {
			t.Errorf("listControls missing %q in:\n%s", want, out)
		}
	}
	if !strings.Contains(out, `active" href="/operator/grants?q=acme">All`) &&
		!strings.Contains(out, `small active" href="/operator/grants?q=acme&amp;state=live">Live</a>`) {
		t.Errorf("active facet pill not marked in:\n%s", out)
	}

	pager := renderListDefine(t, "listPager", nav)
	for _, want := range []string{
		"Showing 51–100 of 120",
		"Page 2 of 3",
		">Previous</a>",
		">Next</a>",
	} {
		if !strings.Contains(pager, want) {
			t.Errorf("listPager missing %q in:\n%s", want, pager)
		}
	}
	if pagerEmpty := renderListDefine(t, "listPager", ListNav{BasePath: "/x", Page: 1, Total: 0}); strings.Contains(pagerEmpty, "Showing") {
		t.Errorf("empty list must render no Showing line, got:\n%s", pagerEmpty)
	}

	noMatch := renderListDefine(t, "listNoMatch", nav)
	if !strings.Contains(noMatch, "No rows match") || !strings.Contains(noMatch, "acme") {
		t.Errorf("listNoMatch must name the term, got:\n%s", noMatch)
	}
	if !strings.Contains(noMatch, `href="/operator/grants"`) {
		t.Errorf("listNoMatch must link the bare list, got:\n%s", noMatch)
	}
}