package web_test

import (
	"context"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

// TestGraphPageRenders proves GET /graph returns an SVG containing every
// seeded root + the filter chip strip and the legend.
func TestGraphPageRenders(t *testing.T) {
	srv, pool := mustServer(t)
	defer pool.Close()
	h := srv.Routes()
	code, body := get(t, h, "/views/graph")
	if code != 200 {
		t.Fatalf("GET /graph → %d body=%s", code, body)
	}
	for _, want := range []string{
		`<svg`,
		`class="gnode`,
		`graph-canvas`,
		`graph-legend`,
		`>work<`,
		`>dev<`,
	} {
		if !strings.Contains(body, want) {
			t.Errorf("graph page missing %q", want)
		}
	}
}

// TestGraphFilterDimsNonMatching: ?tag=nonexistent should dim every node
// (class="dimmed") but never remove them unless isolate=1.
func TestGraphFilterDimsNonMatching(t *testing.T) {
	srv, pool := mustServer(t)
	defer pool.Close()
	h := srv.Routes()

	// Use a definitely-unused tag to force every node to mismatch.
	code, body := get(t, h, "/views/graph?tag=ZZZZ-unused-tag")
	if code != 200 {
		t.Fatalf("GET /graph?tag=ZZZ → %d", code)
	}
	if !strings.Contains(body, "dimmed") {
		t.Errorf("expected at least one dimmed node when filter matches nothing")
	}
	// Body should still contain every root (graph structure preserved).
	if !strings.Contains(body, ">work<") || !strings.Contains(body, ">dev<") {
		t.Errorf("expected dim-mode to keep every node visible (root nodes missing)")
	}
}

// TestGraphIsolateHidesNonMatching: ?isolate=1 + a filter should remove
// non-matching nodes from the rendered SVG.
func TestGraphIsolateHidesNonMatching(t *testing.T) {
	srv, pool := mustServer(t)
	defer pool.Close()
	h := srv.Routes()
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	// Seed a unique tag on one item so the filter has a known target.
	stamp := strings.ReplaceAll(time.Now().UTC().Format("150405.000000"), ".", "")
	slug := "graph-iso-" + stamp
	tag := "graphiso" + stamp
	var dev string
	if err := pool.QueryRow(ctx, `select id from projax.items where slug='dev' and cardinality(parent_ids)=0`).Scan(&dev); err != nil {
		t.Fatalf("dev: %v", err)
	}
	var id string
	if err := pool.QueryRow(ctx,
		`insert into projax.items (kind, title, slug, parent_ids, tags)
		  values (array['project']::text[], 'iso', $1, ARRAY[$2]::uuid[], ARRAY[$3]::text[])
		  returning id`,
		slug, dev, tag,
	).Scan(&id); err != nil {
		t.Fatalf("seed: %v", err)
	}
	defer pool.Exec(context.Background(), `delete from projax.items where id=$1`, id)

	code, body := get(t, h, "/views/graph?tag="+tag+"&isolate=1")
	if code != 200 {
		t.Fatalf("GET /graph?isolate → %d", code)
	}
	if !strings.Contains(body, ">"+slug+"<") {
		t.Errorf("expected isolated slug %q in body", slug)
	}
	// A seeded root that does NOT carry this tag must be hidden.
	if strings.Contains(body, ">finances<") {
		t.Errorf("isolate=1 should hide non-matching nodes — 'finances' still rendered")
	}
}

// TestGraphSVGDownload: ?download=svg returns the raw SVG (no HTML chrome)
// with the right Content-Type + attachment header.
func TestGraphSVGDownload(t *testing.T) {
	srv, pool := mustServer(t)
	defer pool.Close()
	h := srv.Routes()
	req := httptest.NewRequest(http.MethodGet, "/views/graph?download=svg", nil)
	w := httptest.NewRecorder()
	h.ServeHTTP(w, req)
	if w.Result().StatusCode != 200 {
		t.Fatalf("GET /graph?download=svg → %d", w.Result().StatusCode)
	}
	if ct := w.Result().Header.Get("Content-Type"); !strings.HasPrefix(ct, "image/svg+xml") {
		t.Errorf("Content-Type = %q, want image/svg+xml", ct)
	}
	if cd := w.Result().Header.Get("Content-Disposition"); !strings.Contains(cd, "attachment") {
		t.Errorf("Content-Disposition = %q, want attachment", cd)
	}
	bodyBytes, _ := io.ReadAll(w.Result().Body)
	body := string(bodyBytes)
	if !strings.HasPrefix(strings.TrimSpace(body), "<svg") {
		t.Errorf("download body should start with <svg, got: %s", body[:min2(80, len(body))])
	}
	if strings.Contains(body, "<html") {
		t.Errorf("download body should be bare SVG, not HTML")
	}
}

func min2(a, b int) int {
	if a < b {
		return a
	}
	return b
}