package api

import (
	"net/http"
	"testing"

	"github.com/gin-gonic/gin"
)

func fillPath(id int64) string  { return objectPath(id) + "/fill" }
func clearPath(id int64) string { return objectPath(id) + "/clear" }

// makeFillPlant creates a custom plant and returns its id.
//
// Deliberately named apart from the seed-lot tests' helper: that one arrives on
// a separate branch, and two files declaring the same helper would collide on
// whichever merged second.
func makeFillPlant(t *testing.T, r *gin.Engine, cookie *http.Cookie, name string, spacing float64) int64 {
	t.Helper()
	w := doJSON(t, r, http.MethodPost, "/api/v1/plants", map[string]any{
		"name": name, "category": "vegetable", "spacingCm": spacing, "color": "#4a7c3f", "icon": "🌱",
	}, cookie)
	if w.Code != http.StatusCreated {
		t.Fatalf("create plant %q: status %d, body %s", name, w.Code, w.Body.String())
	}
	return int64(decodeMap(t, w.Body.Bytes())["id"].(float64))
}

// seedFillableBed makes a garden with one plantable bed and a custom plant,
// returning (gardenID, objectID, plantID).
func seedFillableBed(t *testing.T, r *gin.Engine, cookie *http.Cookie, w, h, spacing float64) (int64, int64, int64) {
	t.Helper()
	gid := createGardenAPI(t, r, cookie, "G")
	rec := doJSON(t, r, http.MethodPost, objectsPath(gid), map[string]any{
		"kind": "bed", "widthCm": w, "heightCm": h, "plantable": true,
	}, cookie)
	if rec.Code != http.StatusCreated {
		t.Fatalf("create bed: status %d, body %s", rec.Code, rec.Body.String())
	}
	objID := int64(decodeMap(t, rec.Body.Bytes())["id"].(float64))
	plantID := makeFillPlant(t, r, cookie, "Fillable", spacing)
	return gid, objID, plantID
}

// countChangeSets reads the history page and reports how many change sets exist.
func countChangeSets(t *testing.T, r *gin.Engine, cookie *http.Cookie, gardenID int64) int {
	t.Helper()
	w := doJSON(t, r, http.MethodGet, historyPath(gardenID), nil, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("history: status %d, body %s", w.Code, w.Body.String())
	}
	sets, _ := decodeMap(t, w.Body.Bytes())["changeSets"].([]any)
	return len(sets)
}

// TestFillAndClearAPI covers the two routes end to end through the router.
//
// These exist because both operations were previously reachable ONLY through the
// agent toolbox, so on an instance with no model configured the most valuable
// bulk operation in the app did not exist at all.
func TestFillAndClearAPI(t *testing.T) {
	r := authEngine(t, localCfg())
	cookie := registerAndCookie(t, r, "fill@example.com")
	_, objID, plantID := seedFillableBed(t, r, cookie, 200, 200, 20)

	// Fill by compass name.
	w := doJSON(t, r, http.MethodPost, fillPath(objID), map[string]any{
		"plantId": plantID, "region": "all",
	}, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("fill: status %d, body %s", w.Code, w.Body.String())
	}
	body := decodeMap(t, w.Body.Bytes())
	created := int(body["created"].(float64))
	if created == 0 {
		t.Fatalf("fill created nothing: %s", w.Body.String())
	}
	if plops, _ := body["plantings"].([]any); len(plops) != created {
		t.Errorf("created=%d but returned %d plantings", created, len(plops))
	}

	// Clear it: one call, and it reports what it removed.
	w = doJSON(t, r, http.MethodPost, clearPath(objID), nil, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("clear: status %d, body %s", w.Code, w.Body.String())
	}
	if n := int(decodeMap(t, w.Body.Bytes())["cleared"].(float64)); n != created {
		t.Errorf("cleared %d, want %d (everything the fill made)", n, created)
	}

	// Clearing an already-empty bed is a no-op, not an error.
	w = doJSON(t, r, http.MethodPost, clearPath(objID), nil, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("second clear: status %d", w.Code)
	}
	if n := int(decodeMap(t, w.Body.Bytes())["cleared"].(float64)); n != 0 {
		t.Errorf("second clear removed %d, want 0", n)
	}
}

// TestFillRegionSelectionAPI: exactly one of region/rect, and a rect fills only
// its own corner of the bed.
func TestFillRegionSelectionAPI(t *testing.T) {
	r := authEngine(t, localCfg())
	cookie := registerAndCookie(t, r, "region@example.com")
	_, objID, plantID := seedFillableBed(t, r, cookie, 400, 400, 20)

	// Neither → 400. Both → 400. Accepting both and silently preferring one
	// would make a client bug look like a geometry bug.
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), map[string]any{"plantId": plantID}, cookie); w.Code != http.StatusBadRequest {
		t.Errorf("no region = %d, want 400", w.Code)
	}
	both := map[string]any{
		"plantId": plantID, "region": "all",
		"rect": map[string]any{"minXCm": -50, "minYCm": -50, "maxXCm": 50, "maxYCm": 50},
	}
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), both, cookie); w.Code != http.StatusBadRequest {
		t.Errorf("both region and rect = %d, want 400", w.Code)
	}
	// An unknown compass name is rejected rather than silently filling nothing.
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), map[string]any{
		"plantId": plantID, "region": "middle-ish",
	}, cookie); w.Code != http.StatusBadRequest {
		t.Errorf("bad region name = %d, want 400", w.Code)
	}

	// A zero-area rect is malformed input, not "plant one at the centre". An empty
	// `"rect": {}` decodes to all-zeros and must be caught the same way.
	for _, rect := range []map[string]any{
		{}, // {} → 0,0,0,0
		{"minXCm": 10, "minYCm": 10, "maxXCm": 10, "maxYCm": 50}, // zero width
		{"minXCm": 10, "minYCm": 50, "maxXCm": 50, "maxYCm": 50}, // zero height
		{"minXCm": 50, "minYCm": 50, "maxXCm": 10, "maxYCm": 10}, // inverted
	} {
		if w := doJSON(t, r, http.MethodPost, fillPath(objID),
			map[string]any{"plantId": plantID, "rect": rect}, cookie); w.Code != http.StatusBadRequest {
			t.Errorf("degenerate rect %v = %d, want 400", rect, w.Code)
		}
	}

	// A rect confined to the NE corner produces plops only there. Local frame:
	// +x east, -y north.
	w := doJSON(t, r, http.MethodPost, fillPath(objID), map[string]any{
		"plantId": plantID,
		"rect":    map[string]any{"minXCm": 0, "minYCm": -200, "maxXCm": 200, "maxYCm": 0},
	}, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("rect fill: status %d, body %s", w.Code, w.Body.String())
	}
	plops, _ := decodeMap(t, w.Body.Bytes())["plantings"].([]any)
	if len(plops) == 0 {
		t.Fatal("rect fill created nothing")
	}
	for _, raw := range plops {
		p := raw.(map[string]any)
		if x, y := p["xCm"].(float64), p["yCm"].(float64); x < 0 || y > 0 {
			t.Errorf("plop at (%v,%v) outside the NE rect", x, y)
		}
	}
}

// TestClearObjectIsOneChangeSetAPI is the regression test for the behaviour this
// endpoint exists to restore.
//
// The UI used to clear a bed with a loop of PATCHes, and since every service
// mutation auto-scopes its own change set, clearing a 40-plop bed wrote 40 of
// them — 40 presses of Undo to put the bed back. CLAUDE.md states the rule
// directly: multi-row operations record together so they undo as one unit.
func TestClearObjectIsOneChangeSetAPI(t *testing.T) {
	r := authEngine(t, localCfg())
	cookie := registerAndCookie(t, r, "onecs@example.com")
	gid, objID, plantID := seedFillableBed(t, r, cookie, 300, 300, 20)

	w := doJSON(t, r, http.MethodPost, fillPath(objID), map[string]any{
		"plantId": plantID, "region": "all",
	}, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("fill: status %d, body %s", w.Code, w.Body.String())
	}
	created := int(decodeMap(t, w.Body.Bytes())["created"].(float64))
	if created < 4 {
		t.Fatalf("need several plops to make this meaningful, got %d", created)
	}

	before := countChangeSets(t, r, cookie, gid)
	if w := doJSON(t, r, http.MethodPost, clearPath(objID), nil, cookie); w.Code != http.StatusOK {
		t.Fatalf("clear: status %d", w.Code)
	}
	if after := countChangeSets(t, r, cookie, gid); after != before+1 {
		t.Errorf("clearing %d plops added %d change sets, want exactly 1", created, after-before)
	}
}

// TestFillClearPermissionsAPI: a viewer may look but not fill or clear, and a
// stranger gets 404 because existence is masked.
func TestFillClearPermissionsAPI(t *testing.T) {
	r := authEngine(t, localCfg())
	owner := registerAndCookie(t, r, "owner-fill@example.com")
	viewer := registerAndCookie(t, r, "viewer-fill@example.com")
	stranger := registerAndCookie(t, r, "stranger-fill@example.com")

	gid, objID, plantID := seedFillableBed(t, r, owner, 200, 200, 20)
	if w := doJSON(t, r, http.MethodPost, sharesPath(gid),
		map[string]any{"email": "viewer-fill@example.com", "role": "viewer"}, owner); w.Code != http.StatusCreated {
		t.Fatalf("share as viewer: status %d, body %s", w.Code, w.Body.String())
	}

	fillBody := map[string]any{"plantId": plantID, "region": "all"}
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), fillBody, viewer); w.Code != http.StatusForbidden {
		t.Errorf("viewer fill = %d, want 403 (they can see it but may not do that)", w.Code)
	}
	if w := doJSON(t, r, http.MethodPost, clearPath(objID), nil, viewer); w.Code != http.StatusForbidden {
		t.Errorf("viewer clear = %d, want 403", w.Code)
	}
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), fillBody, stranger); w.Code != http.StatusNotFound {
		t.Errorf("stranger fill = %d, want 404 (existence masked)", w.Code)
	}
	if w := doJSON(t, r, http.MethodPost, clearPath(objID), nil, stranger); w.Code != http.StatusNotFound {
		t.Errorf("stranger clear = %d, want 404", w.Code)
	}
	if w := doJSON(t, r, http.MethodPost, fillPath(objID), fillBody, nil); w.Code != http.StatusUnauthorized {
		t.Errorf("anonymous fill = %d, want 401", w.Code)
	}
}