package tool

import (
	"context"
	"errors"
	"reflect"
	"testing"
	"time"

	"github.com/kami/maven/internal/ipc"
)

// fakeAPI — an in-memory tool store for the executor/matcher tests.
type fakeAPI struct{ tools map[string]ipc.Tool }

func (f fakeAPI) LookupTool(_ context.Context, name string) (ipc.Tool, error) {
	t, ok := f.tools[name]
	if !ok {
		return ipc.Tool{}, ipc.ErrToolNotFound
	}
	return t, nil
}
func (f fakeAPI) ListTools(_ context.Context, status string) ([]ipc.Tool, error) {
	var out []ipc.Tool
	for _, t := range f.tools {
		if status == "" || t.Status == status {
			out = append(out, t)
		}
	}
	return out, nil
}
func (f fakeAPI) ProposeTool(_ context.Context, _, _, _ string, _ time.Time) (bool, error) {
	return true, nil
}

// TestExec covers the allowlist boundary: enabled runs, unknown/proposed refuse,
// destructive needs confirm, and args land as argv (no shell) after the prefix.
func TestExec(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"restart": {Name: "restart", Scope: "homelab", Cmd: []string{"systemctl", "restart"}, Status: "enabled"},
		"drop":    {Name: "drop", Scope: "homelab", Cmd: []string{"dropdb"}, Destructive: true, Status: "enabled"},
		"draft":   {Name: "draft", Scope: "homelab", Cmd: []string{"x"}, Status: "proposed"},
	}}

	var gotArgv []string
	e := NewExecutor(api, 0)
	e.run = func(_ context.Context, argv []string) (string, error) { gotArgv = argv; return "ok", nil }

	// enabled → runs, args appended to the fixed prefix as argv.
	out, err := e.Exec(context.Background(), "restart", []string{"nginx; rm -rf /"}, false)
	if err != nil || out != "ok" {
		t.Fatalf("enabled: out=%q err=%v", out, err)
	}
	want := []string{"systemctl", "restart", "nginx; rm -rf /"}
	if !reflect.DeepEqual(gotArgv, want) {
		t.Fatalf("argv=%v want %v (injection must stay one argv element)", gotArgv, want)
	}

	// unknown → refuse.
	if _, err := e.Exec(context.Background(), "nope", nil, false); !errors.Is(err, ErrNotEnabled) {
		t.Fatalf("unknown: err=%v want ErrNotEnabled", err)
	}
	// proposed (not enabled) → refuse.
	if _, err := e.Exec(context.Background(), "draft", nil, false); !errors.Is(err, ErrNotEnabled) {
		t.Fatalf("proposed: err=%v want ErrNotEnabled", err)
	}
	// destructive unconfirmed → needs confirm; confirmed → runs.
	if _, err := e.Exec(context.Background(), "drop", nil, false); !errors.Is(err, ErrNeedsConfirm) {
		t.Fatalf("destructive: err=%v want ErrNeedsConfirm", err)
	}
	if _, err := e.Exec(context.Background(), "drop", []string{"db"}, true); err != nil {
		t.Fatalf("destructive confirmed: err=%v", err)
	}
	if want := []string{"dropdb", "db"}; !reflect.DeepEqual(gotArgv, want) {
		t.Fatalf("confirmed argv=%v want %v", gotArgv, want)
	}

	// matcher allowlist = enabled names only (proposed excluded).
	m := NewMatcher(api)
	fn, args, ok := m.Match("restart nginx")
	if !ok || fn != "restart" || !reflect.DeepEqual(args, []string{"nginx"}) {
		t.Fatalf("match: fn=%q args=%v ok=%v", fn, args, ok)
	}
	if _, _, ok := m.Match("draft something"); ok {
		t.Fatal("proposed tool must not match (not enabled)")
	}
}

// fakeMCP records what the executor asked it to call.
type fakeMCP struct {
	server, tool string
	args         []string
	out          string
	err          error
	calls        int
}

func (f *fakeMCP) CallPositional(_ context.Context, server, tool string, args []string) (string, error) {
	f.calls++
	f.server, f.tool, f.args = server, tool, args
	return f.out, f.err
}

// An MCP row dispatches to the caller instead of a process, and the process
// seam is never touched.
func TestExecMCPRowDispatchesToMCP(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"vikunja_list_tasks": {
			Name: "vikunja_list_tasks", Status: "enabled", Scope: "mcp:vikunja",
			Cmd: []string{"mcp", "vikunja", "list_tasks"},
		},
	}}
	m := &fakeMCP{out: "две задачи"}
	ran := false
	e := NewExecutor(api, time.Second).WithMCP(m)
	e.run = func(context.Context, []string) (string, error) { ran = true; return "", nil }

	out, err := e.Exec(context.Background(), "vikunja_list_tasks", []string{"мавен"}, false)
	if err != nil {
		t.Fatalf("exec: %v", err)
	}
	if out != "две задачи" {
		t.Fatalf("out = %q", out)
	}
	if ran {
		t.Fatal("an MCP row must not be executed as a process")
	}
	if m.server != "vikunja" || m.tool != "list_tasks" || len(m.args) != 1 || m.args[0] != "мавен" {
		t.Fatalf("dispatched wrong: %+v", m)
	}
}

// The allowlist rules still apply to an MCP row: destructive means a confirm
// turn first, and nothing is called until the second turn.
func TestExecMCPRowStillNeedsConfirm(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"vikunja_delete_task": {
			Name: "vikunja_delete_task", Status: "enabled", Destructive: true,
			Cmd: []string{"mcp", "vikunja", "delete_task"},
		},
	}}
	m := &fakeMCP{out: "удалила"}
	e := NewExecutor(api, time.Second).WithMCP(m)
	if _, err := e.Exec(context.Background(), "vikunja_delete_task", nil, false); !errors.Is(err, ErrNeedsConfirm) {
		t.Fatalf("err = %v, want ErrNeedsConfirm", err)
	}
	if m.calls != 0 {
		t.Fatal("a destructive MCP tool must not reach the server before confirmation")
	}
	if _, err := e.Exec(context.Background(), "vikunja_delete_task", nil, true); err != nil {
		t.Fatalf("confirmed exec: %v", err)
	}
	if m.calls != 1 {
		t.Fatalf("calls = %d", m.calls)
	}
}

// A proposed MCP row does not run, exactly like a proposed shell tool.
func TestExecMCPRowNotEnabled(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"vikunja_list_tasks": {Name: "vikunja_list_tasks", Status: "proposed", Cmd: []string{"mcp", "vikunja", "list_tasks"}},
	}}
	m := &fakeMCP{}
	e := NewExecutor(api, time.Second).WithMCP(m)
	if _, err := e.Exec(context.Background(), "vikunja_list_tasks", nil, false); !errors.Is(err, ErrNotEnabled) {
		t.Fatalf("err = %v", err)
	}
	if m.calls != 0 {
		t.Fatal("a proposal must not call anything")
	}
}

// With MCP unconfigured, an MCP row refuses rather than trying to exec "mcp".
func TestExecMCPRowWithoutCallerRefuses(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"vikunja_list_tasks": {Name: "vikunja_list_tasks", Status: "enabled", Cmd: []string{"mcp", "vikunja", "list_tasks"}},
	}}
	ran := false
	e := NewExecutor(api, time.Second)
	e.run = func(context.Context, []string) (string, error) { ran = true; return "", nil }
	err := func() error { _, e2 := e.Exec(context.Background(), "vikunja_list_tasks", nil, false); return e2 }()
	// ErrNotConnected, NOT ErrNotEnabled: the act path turns ErrNotEnabled into
	// a fresh proposal, and drafting a proposal for a row that already exists
	// and is enabled answers the wrong question.
	if !errors.Is(err, ErrNotConnected) {
		t.Fatalf("err = %v, want ErrNotConnected", err)
	}
	if errors.Is(err, ErrNotEnabled) {
		t.Fatal("an enabled row with a missing backend must not read as not-enabled")
	}
	if ran {
		t.Fatal(`"mcp" must never be run as a binary`)
	}
}

// fakeHome records what the executor asked the house to do.
type fakeHome struct {
	entity, service string
	calls           int
}

func (f *fakeHome) CallService(_ context.Context, entityID, service string) (string, error) {
	f.calls++
	f.entity, f.service = entityID, service
	return "готово", nil
}

// A house row goes through the same allowlist and the same confirm turn as any
// other act, and it is never exec'd as a binary (Vikunja #256).
func TestExecSmartHomeRow(t *testing.T) {
	api := fakeAPI{tools: map[string]ipc.Tool{
		"home_light_x_off": {
			Name: "home_light_x_off", Scope: "smarthome:light",
			Cmd: []string{"smarthome", "light.x", "turn_off"}, Destructive: true, Status: "enabled",
		},
		"home_draft": {
			Name: "home_draft", Scope: "smarthome:light",
			Cmd: []string{"smarthome", "light.y", "turn_on"}, Destructive: true, Status: "proposed",
		},
	}}
	ran := false
	newExec := func(h HomeCaller) *Executor {
		e := NewExecutor(api, time.Second)
		e.run = func(context.Context, []string) (string, error) { ran = true; return "", nil }
		if h != nil {
			e = e.WithHome(h)
		}
		return e
	}

	// No house configured ⇒ the row refuses rather than being exec'd.
	if _, err := newExec(nil).Exec(context.Background(), "home_light_x_off", nil, true); !errors.Is(err, ErrNotConnected) {
		t.Fatalf("unconfigured house: err = %v, want ErrNotConnected", err)
	}
	if ran {
		t.Fatal(`"smarthome" was run as a binary`)
	}

	// Configured, but not confirmed ⇒ the confirm turn, before any call.
	fh := &fakeHome{}
	if _, err := newExec(fh).Exec(context.Background(), "home_light_x_off", nil, false); !errors.Is(err, ErrNeedsConfirm) {
		t.Fatalf("err = %v, want ErrNeedsConfirm", err)
	}
	if fh.calls != 0 {
		t.Fatal("an unconfirmed house act reached the house")
	}

	// A merely proposed row never runs, confirmed or not.
	if _, err := newExec(fh).Exec(context.Background(), "home_draft", nil, true); !errors.Is(err, ErrNotEnabled) {
		t.Fatalf("proposed row: err = %v, want ErrNotEnabled", err)
	}
	if fh.calls != 0 {
		t.Fatal("a proposed house row reached the house")
	}

	// Confirmed ⇒ the service call, with the entity from the ROW and the
	// spoken tail dropped.
	out, err := newExec(fh).Exec(context.Background(), "home_light_x_off", []string{"light.somewhere_else"}, true)
	if err != nil {
		t.Fatalf("Exec: %v", err)
	}
	if out != "готово" {
		t.Errorf("out = %q", out)
	}
	if fh.entity != "light.x" || fh.service != "turn_off" {
		t.Errorf("called %s/%s: the target must come from the enabled row, never from the utterance", fh.entity, fh.service)
	}
	if ran {
		t.Fatal(`"smarthome" was run as a binary`)
	}
}