package mail

import (
	"os"
	"path/filepath"
	"testing"
)

func TestDetectTownRoot(t *testing.T) {
	// Create temp directory structure
	tmpDir := t.TempDir()
	townRoot := filepath.Join(tmpDir, "town")
	mayorDir := filepath.Join(townRoot, "mayor")
	rigDir := filepath.Join(townRoot, "gastown", "polecats", "test")

	// Create mayor/town.json marker
	if err := os.MkdirAll(mayorDir, 0755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(mayorDir, "town.json"), []byte("{}"), 0644); err != nil {
		t.Fatal(err)
	}
	if err := os.MkdirAll(rigDir, 0755); err != nil {
		t.Fatal(err)
	}

	tests := []struct {
		name     string
		startDir string
		want     string
	}{
		{
			name:     "from town root",
			startDir: townRoot,
			want:     townRoot,
		},
		{
			name:     "from rig subdirectory",
			startDir: rigDir,
			want:     townRoot,
		},
		{
			name:     "from mayor directory",
			startDir: mayorDir,
			want:     townRoot,
		},
		{
			name:     "from non-town directory",
			startDir: tmpDir,
			want:     "", // No town.json marker above tmpDir
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := detectTownRoot(tt.startDir)
			if got != tt.want {
				t.Errorf("detectTownRoot(%q) = %q, want %q", tt.startDir, got, tt.want)
			}
		})
	}
}

func TestIsTownLevelAddress(t *testing.T) {
	tests := []struct {
		address string
		want    bool
	}{
		{"mayor", true},
		{"mayor/", true},
		{"deacon", true},
		{"deacon/", true},
		{"gastown/refinery", false},
		{"gastown/polecats/Toast", false},
		{"gastown/", false},
		{"", false},
	}

	for _, tt := range tests {
		t.Run(tt.address, func(t *testing.T) {
			got := isTownLevelAddress(tt.address)
			if got != tt.want {
				t.Errorf("isTownLevelAddress(%q) = %v, want %v", tt.address, got, tt.want)
			}
		})
	}
}

func TestAddressToSessionID(t *testing.T) {
	tests := []struct {
		address string
		want    string
	}{
		{"mayor", "gt-mayor"},
		{"mayor/", "gt-mayor"},
		{"gastown/refinery", "gt-gastown-refinery"},
		{"gastown/Toast", "gt-gastown-Toast"},
		{"beads/witness", "gt-beads-witness"},
		{"gastown/", ""},   // Empty target
		{"gastown", ""},    // No slash
		{"", ""},           // Empty address
	}

	for _, tt := range tests {
		t.Run(tt.address, func(t *testing.T) {
			got := addressToSessionID(tt.address)
			if got != tt.want {
				t.Errorf("addressToSessionID(%q) = %q, want %q", tt.address, got, tt.want)
			}
		})
	}
}

func TestIsSelfMail(t *testing.T) {
	tests := []struct {
		from string
		to   string
		want bool
	}{
		{"mayor/", "mayor/", true},
		{"mayor", "mayor/", true},
		{"mayor/", "mayor", true},
		{"gastown/Toast", "gastown/Toast", true},
		{"gastown/Toast/", "gastown/Toast", true},
		{"mayor/", "deacon/", false},
		{"gastown/Toast", "gastown/Nux", false},
		{"", "", true},
	}

	for _, tt := range tests {
		t.Run(tt.from+"->"+tt.to, func(t *testing.T) {
			got := isSelfMail(tt.from, tt.to)
			if got != tt.want {
				t.Errorf("isSelfMail(%q, %q) = %v, want %v", tt.from, tt.to, got, tt.want)
			}
		})
	}
}

func TestShouldBeWisp(t *testing.T) {
	r := &Router{}

	tests := []struct {
		name    string
		msg     *Message
		want    bool
	}{
		{
			name: "explicit wisp flag",
			msg:  &Message{Subject: "Regular message", Wisp: true},
			want: true,
		},
		{
			name: "POLECAT_STARTED subject",
			msg:  &Message{Subject: "POLECAT_STARTED: Toast"},
			want: true,
		},
		{
			name: "polecat_done subject (lowercase)",
			msg:  &Message{Subject: "polecat_done: work complete"},
			want: true,
		},
		{
			name: "NUDGE subject",
			msg:  &Message{Subject: "NUDGE: check your hook"},
			want: true,
		},
		{
			name: "START_WORK subject",
			msg:  &Message{Subject: "START_WORK: gt-123"},
			want: true,
		},
		{
			name: "regular message",
			msg:  &Message{Subject: "Please review this PR"},
			want: false,
		},
		{
			name: "handoff message (not auto-wisp)",
			msg:  &Message{Subject: "HANDOFF: context notes"},
			want: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := r.shouldBeWisp(tt.msg)
			if got != tt.want {
				t.Errorf("shouldBeWisp(%v) = %v, want %v", tt.msg.Subject, got, tt.want)
			}
		})
	}
}

func TestResolveBeadsDir(t *testing.T) {
	// With town root set
	r := NewRouterWithTownRoot("/work/dir", "/home/user/gt")
	got := r.resolveBeadsDir("gastown/Toast")
	want := "/home/user/gt/.beads"
	if got != want {
		t.Errorf("resolveBeadsDir with townRoot = %q, want %q", got, want)
	}

	// Without town root (fallback to workDir)
	r2 := &Router{workDir: "/work/dir", townRoot: ""}
	got2 := r2.resolveBeadsDir("mayor/")
	want2 := "/work/dir/.beads"
	if got2 != want2 {
		t.Errorf("resolveBeadsDir without townRoot = %q, want %q", got2, want2)
	}
}

func TestNewRouterWithTownRoot(t *testing.T) {
	r := NewRouterWithTownRoot("/work/rig", "/home/gt")
	if r.workDir != "/work/rig" {
		t.Errorf("workDir = %q, want '/work/rig'", r.workDir)
	}
	if r.townRoot != "/home/gt" {
		t.Errorf("townRoot = %q, want '/home/gt'", r.townRoot)
	}
}