package main

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"git.novox.be/novox/mesh-sdk/go/buildstep"
	"git.novox.be/novox/mesh-sdk/go/delivery"
	"git.novox.be/novox/mesh-sdk/go/forgekey"
	"git.novox.be/novox/mesh-sdk/go/health"
)

const underTheFloor = "refused: ace has 4 GiB free under the floor of 20 GiB"

func underFloor(node string) buildstep.Floor {
	f := floorOf(node)
	f.Free = func(string) (uint64, error) { return 4 << 30, nil }
	return f
}

// 1839/AC4: the module as main makes it keeps build-agent's floor of 20 GiB.
func TestTheModuleKeepsTheFloorOf20GiB(t *testing.T) {
	if f := floorOf("ace"); f.Bytes != 20<<30 || f.Node != "ace" {
		t.Errorf("floorOf = %+v, want ace and 20 GiB", f)
	}
}

// 1839/AC1: under the floor every step tool is refused, naming the node, what is free and the floor, no step runs, and
// the module is unhealthy saying so, so the builder chooses another node.
func TestUnderTheFloorEveryStepIsRefusedAndTheModuleIsUnhealthy(t *testing.T) {
	states := newStates()
	m := moduleWith(states, "v26.10.0")
	m.Work, m.Floor = t.TempDir(), underFloor("ace")
	ran := false
	run := func(context.Context, map[string]any) (any, error) { ran = true; return "done", nil }
	steps := []StepTool{{Name: "long_probe", Long: true, Run: run}, {Name: "short_probe", Run: run}}
	for _, tool := range m.Tools(steps) {
		switch tool.Name {
		case "long_probe":
			if _, err := tool.Run(map[string]any{}); err != nil {
				t.Fatal(err)
			}
			if st := states.waitEnd(t); st.State != delivery.StepRefused || !strings.HasPrefix(st.Reason, underTheFloor) {
				t.Errorf("the long step ended %s: %q, want refused: %q", st.State, st.Reason, underTheFloor)
			}
		case "short_probe":
			if _, err := tool.Run(map[string]any{}); err == nil || !strings.HasPrefix(err.Error(), underTheFloor) {
				t.Errorf("the short step answered %v, want %q", err, underTheFloor)
			}
		}
	}
	if ran {
		t.Errorf("a step ran under the floor")
	}
	if a := m.Health(context.Background()); a.State != health.StateUnhealthy || !strings.HasPrefix(a.Why, underTheFloor) {
		t.Errorf("health = %+v, want unhealthy: %q", a, underTheFloor)
	}
}

func releaseTool(t *testing.T, m *Module) func(map[string]any) (any, error) {
	t.Helper()
	for _, tool := range m.Tools(m.StepTools()) {
		if tool.Name == ReleaseTool {
			return tool.Run
		}
	}
	t.Fatalf("no tool %s", ReleaseTool)
	return nil
}

// 1839/AC2: build_node_release removes the workspace at once, even under the floor; a second release is no error.
func TestReleaseRemovesTheWorkspaceAtOnce(t *testing.T) {
	m, _, work := newMachine(t)
	m.Floor = underFloor("ace")
	ws := filepath.Join(work, "abc1")
	os.MkdirAll(filepath.Join(ws, "tree"), 0o700)
	for i := 0; i < 2; i++ {
		if _, err := releaseTool(t, m)(map[string]any{"workspace": "abc1"}); err != nil {
			t.Fatalf("release %d: %v", i, err)
		}
	}
	if _, err := os.Stat(ws); !os.IsNotExist(err) {
		t.Errorf("the workspace is still there after its release")
	}
}

// 1839/AC2: a fetch that fails leaves no workspace behind: nobody was told its id, so nobody could release it.
func TestAFailedFetchLeavesNoWorkspace(t *testing.T) {
	m, f := fetchMachine(t, typeScriptModule(`{}`), nil)
	f.answer["git fetch"] = forgekey.Ran{Status: 128, Stderr: "fatal: unreachable"}
	if _, err := m.fetch(context.Background(), fetchArgs); err == nil {
		t.Fatal("the fetch passed, want it failed")
	}
	if entries, _ := os.ReadDir(m.Work); len(entries) != 0 {
		t.Errorf("the failed fetch left %d entries in the work directory", len(entries))
	}
}

// 1839/AC3: a workspace a running step holds is never swept, however old; an unheld one past the two-hour bound is,
// also at the module's own round and not only at a fetch.
func TestTheSweepKeepsAHeldWorkspaceAndRemovesAnUnheldOnePastTwoHours(t *testing.T) {
	m := &Module{Work: t.TempDir()}
	for _, name := range []string{"held1", "lost1"} {
		os.MkdirAll(filepath.Join(m.Work, name, "tree"), 0o755)
	}
	done := m.spaces().Hold("held1")
	defer done()
	when := time.Now().Add(-3 * time.Hour)
	for _, name := range []string{"held1", "lost1"} {
		os.Chtimes(filepath.Join(m.Work, name), when, when)
	}
	m.CleanWorkspaces(time.Now())
	if _, err := os.Stat(filepath.Join(m.Work, "held1")); err != nil {
		t.Errorf("the held workspace was swept")
	}
	if _, err := os.Stat(filepath.Join(m.Work, "lost1")); !os.IsNotExist(err) {
		t.Errorf("the unheld workspace three hours old was kept")
	}
}