package seo_test

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
	"testing"
)

const bom = "\ufeff"

// transferAction calls the import and export screen's widget action.
func (e *testEnv) transferAction(t *testing.T, token string, delimiter string, payload map[string]any) map[string]any {
	t.Helper()
	rec := e.expect(t, http.StatusOK, http.MethodPost, adminAPI("/golem15/seo/transfer/widgets/_transfer"), token, map[string]any{
		"record_id": 1,
		"values":    map[string]any{"csv_delimiter": delimiter},
		"payload":   payload,
	})
	var out struct {
		Data struct {
			Data    map[string]any `json:"data"`
			Message string         `json:"message"`
		} `json:"data"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &out); err != nil {
		t.Fatalf("decode %s: %v", rec.Body.String(), err)
	}
	if out.Data.Data == nil {
		out.Data.Data = map[string]any{}
	}
	out.Data.Data["_message"] = out.Data.Message
	return out.Data.Data
}

// summary reads an import answer's summary as counts.
func summary(t *testing.T, body map[string]any) map[string]int {
	t.Helper()
	raw, _ := body["summary"].(map[string]any)
	out := map[string]int{}
	for k, v := range raw {
		f, _ := v.(float64)
		out[k] = int(f)
	}
	return out
}

// TestCSVTransfer checks D-13 import and export (P-27, T-32-24/25/29):
// the export is UTF-8 with a BOM, the chosen delimiter and formula cells
// prefixed with an apostrophe, and importing it back changes nothing;
// missing columns and unreadable files are refused; a looping row is
// refused and blocks the apply; a records row without a record becomes a
// URL rule; the admin's apply token is refused once the data changed and
// applies one import batch when fresh; size caps hold on both paths.
func TestCSVTransfer(t *testing.T) {
	env := bootEnv(t)
	token := env.admin(t, true)
	env.createPage(t, token, map[string]any{"title": "Page A", "slug": "a", "excerpt": "About A", "published": true})
	agent := env.principal(t, env.admin(t, false, "golem15.seo.manage"))
	env.mcpExpect(t, http.StatusCreated, http.MethodPost, "/_seo/api/v1/redirects", agent, map[string]any{"source": "/e1", "target": "/t1", "note": "=cmd"})
	env.mcpExpect(t, http.StatusCreated, http.MethodPost, "/_seo/api/v1/redirects", agent, map[string]any{"source": "/e2", "target": "/t2", "status": 302})

	exp := env.mcpExpect(t, http.StatusOK, http.MethodGet, "/_seo/api/v1/export?dataset=redirects&delimiter=%3B", agent, nil)
	csv, _ := exp["csv"].(string)
	if !strings.HasPrefix(csv, bom+"source;match;target;status;query;ignore_case;trailing_slash;note") {
		t.Fatalf("export = %q, want a BOM and the semicolon header", csv)
	}
	if !strings.Contains(csv, "'=cmd") || strings.Contains(csv, ";=cmd") {
		t.Fatalf("export = %q, want the formula cell prefixed with an apostrophe", csv)
	}
	if !strings.HasPrefix(fmt.Sprint(exp["filename"]), "seo-redirects-") {
		t.Fatalf("filename = %v", exp["filename"])
	}

	// A huge page number is an empty page, not a panic (WR-14); so is a
	// list page.
	far := env.mcpExpect(t, http.StatusOK, http.MethodGet, "/_seo/api/v1/export?dataset=redirects&page=9223372036854777", agent, nil)
	if c, _ := far["csv"].(string); strings.Contains(c, "/e1") {
		t.Fatalf("export of a huge page = %v, want no rows", far)
	}
	if l := env.mcpExpect(t, http.StatusOK, http.MethodGet, "/_seo/api/v1/redirects?page=9223372036854775807&per_page=200", agent, nil); len(l["data"].([]any)) != 0 {
		t.Fatalf("list of a huge page = %v, want no rows", l)
	}

	preview := env.mcpExpect(t, http.StatusOK, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": csv, "delimiter": ";", "dry_run": true})
	if s := summary(t, preview); s["unchanged"] != 2 || s["new"] != 0 || s["changed"] != 0 || s["refused"] != 0 {
		t.Fatalf("re-import of the export = %v, want 2 unchanged", preview)
	}

	// Refusals of the file as a whole.
	odd := env.mcpExpect(t, http.StatusOK, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": "source;match;target;query\n/g1;glob;/x;ignore\n/g2;exact;/x;keep\n", "delimiter": ";", "dry_run": true})
	if s := summary(t, odd); s["refused"] != 2 {
		t.Fatalf("import with an unknown match and query = %v, want 2 refused rows (WR-17)", odd)
	}
	rec := env.mcp(t, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": "target;status\n/x;301\n", "delimiter": ";", "dry_run": true})
	if rec.Code != http.StatusUnprocessableEntity || !strings.Contains(rec.Body.String(), `"error":"missing_column"`) || !strings.Contains(rec.Body.String(), "source") {
		t.Fatalf("missing column = %d %s", rec.Code, rec.Body.String())
	}
	rec = env.mcp(t, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": "source;target\n\"/x;/y\n", "delimiter": ";", "dry_run": true})
	if rec.Code != http.StatusUnprocessableEntity || !strings.Contains(rec.Body.String(), `"error":"unreadable"`) {
		t.Fatalf("unreadable = %d %s", rec.Code, rec.Body.String())
	}
	if rec := env.mcp(t, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "nope", "csv": "a\n"}); rec.Code != http.StatusUnprocessableEntity {
		t.Fatalf("unknown dataset = %d, want 422", rec.Code)
	}

	// A looping row is refused and nothing is applied.
	looping := "source,target\n/new1,/t1\n/e1x,/e1\n/t1,/new1\n"
	preview = env.mcpExpect(t, http.StatusOK, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": looping, "delimiter": ",", "dry_run": true})
	if s := summary(t, preview); s["refused"] != 1 || s["new"] != 2 {
		t.Fatalf("looping preview = %v", preview)
	}
	if !strings.Contains(fmt.Sprint(preview["rows"]), "Creates a redirect loop") {
		t.Fatalf("looping rows = %v, want transfer.row_loop", preview["rows"])
	}
	before := env.redirectCount(t)
	rec = env.mcp(t, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": looping, "delimiter": ","})
	if rec.Code != http.StatusUnprocessableEntity || !strings.Contains(rec.Body.String(), `"error":"import_refused"`) {
		t.Fatalf("looping apply = %d %s, want 422 import_refused", rec.Code, rec.Body.String())
	}
	if n := env.redirectCount(t); n != before {
		t.Fatalf("redirects after a refused import = %d, want %d", n, before)
	}

	// Records address pages by URL; no record means a URL rule.
	records := "url;locale;title;robots\n/pages/a;en;Imported;noindex\n/no-record;;Rule title;\n"
	preview = env.mcpExpect(t, http.StatusOK, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "records", "csv": records, "delimiter": ";", "dry_run": true})
	if s := summary(t, preview); s["changed"] != 1 || s["new"] != 1 {
		t.Fatalf("records preview = %v", preview)
	}
	if !strings.Contains(fmt.Sprint(preview["rows"]), "No record at this address") {
		t.Fatalf("records rows = %v, want transfer.row_rule", preview["rows"])
	}
	applied := env.mcpExpect(t, http.StatusOK, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "records", "csv": records, "delimiter": ";"})
	if applied["applied"] != true || applied["count"] != float64(2) {
		t.Fatalf("records apply = %v", applied)
	}
	if got := env.resolve(t, "/no-record"); got["action"] != "ok" || got["seo"].(map[string]any)["title"] != "Rule title" {
		t.Fatalf("resolve /no-record = %v, want the imported rule", got)
	}

	// The admin screen: a stale token is refused, a fresh one applies.
	if fields := env.formSchema(t, token, "golem15/seo/transfer"); len(fields) < 2 {
		t.Fatalf("transfer form = %v", fields)
	}
	file := "source;target;status\n/admin1;/pages/a;301\n/e2;/t2-new;302\n"
	prev := env.transferAction(t, token, ";", map[string]any{"op": "preview", "dataset": "redirects", "csv": file})
	tok, _ := prev["token"].(string)
	if tok == "" || summary(t, prev)["new"] != 1 || summary(t, prev)["changed"] != 1 {
		t.Fatalf("admin preview = %v", prev)
	}
	env.mcpExpect(t, http.StatusCreated, http.MethodPost, "/_seo/api/v1/redirects", agent, map[string]any{"source": "/admin1", "target": "/elsewhere"})
	stale := env.transferAction(t, token, ";", map[string]any{"op": "apply", "token": tok})
	if stale["error"] != "stale" || !strings.Contains(fmt.Sprint(stale["message"]), "The data changed after the preview") {
		t.Fatalf("stale apply = %v, want transfer.stale", stale)
	}
	forged := env.transferAction(t, token, ";", map[string]any{"op": "apply", "token": tok + "x"})
	if forged["error"] == nil {
		t.Fatalf("forged token = %v, want a refusal", forged)
	}
	prev = env.transferAction(t, token, ";", map[string]any{"op": "preview", "dataset": "redirects", "csv": file})
	done := env.transferAction(t, token, ";", map[string]any{"op": "apply", "token": prev["token"]})
	if done["applied"] != true || !strings.Contains(fmt.Sprint(done["_message"]), "Applied 2 changes as one batch") {
		t.Fatalf("apply = %v", done)
	}
	var vias []string
	if err := env.db.Raw(`SELECT DISTINCT via FROM golem15_seo_revisions WHERE batch_id = ?`, done["batch_id"]).Scan(&vias).Error; err != nil || len(vias) != 1 || vias[0] != "import" {
		t.Fatalf("import batch vias = %v err=%v, want import", vias, err)
	}
	var origin string
	if err := env.db.Raw(`SELECT origin FROM golem15_seo_redirects WHERE source = '/e2'`).Scan(&origin).Error; err != nil || origin != "mcp" {
		t.Fatalf("an updated redirect keeps its origin: %q err=%v", origin, err)
	}

	// Export through the screen, and the size caps.
	out := env.transferAction(t, token, ",", map[string]any{"op": "export", "dataset": "rules"})
	if c := fmt.Sprint(out["csv"]); !strings.HasPrefix(c, bom+"url,match,title") || !strings.Contains(c, "/no-record") {
		t.Fatalf("admin export = %v", out)
	}
	big := "source;target\n" + strings.Repeat("/a-long-source-address;/a-long-target-address\n", 1350)
	if tooLarge := env.transferAction(t, token, ";", map[string]any{"op": "preview", "dataset": "redirects", "csv": big}); tooLarge["error"] != "too_large" {
		t.Fatalf("admin import over 60 KB = %v, want too_large", tooLarge)
	}
	huge := "source;target\n" + strings.Repeat("/a-long-source-address;/a-long-target-address\n", 21000)
	if rec := env.mcp(t, http.MethodPost, "/_seo/api/v1/import", agent, map[string]any{"dataset": "redirects", "csv": huge, "dry_run": true}); rec.Code != http.StatusRequestEntityTooLarge {
		t.Fatalf("MCP import over 900 KB = %d, want 413", rec.Code)
	}
}