package collector

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

func TestRevisionPattern(t *testing.T) {
	tests := []struct {
		version string
		wantRev string
	}{
		{"25.11.20260203.e576e3c", "e576e3c"},
		{"1994-294a625", "294a625"},
		{"25.05.20250101.abcdef1234567890", "abcdef1234567890"},
		{"no-revision-here", ""},
		{"", ""},
	}

	for _, tt := range tests {
		t.Run(tt.version, func(t *testing.T) {
			matches := revisionPattern.FindStringSubmatch(tt.version)
			var got string
			if matches != nil {
				got = matches[1]
			}
			if got != tt.wantRev {
				t.Errorf("revisionPattern.FindStringSubmatch(%q) = %q, want %q", tt.version, got, tt.wantRev)
			}
		})
	}
}

func TestGetCurrentSystemRevision(t *testing.T) {
	// Skip if not on NixOS
	if _, err := os.Stat(nixosVersionPath); os.IsNotExist(err) {
		t.Skip("not running on NixOS")
	}

	rev, err := getCurrentSystemRevision()
	if err != nil {
		t.Fatal(err)
	}

	// Just check it returns something reasonable
	t.Logf("current system revision: %s", rev)
}

func TestGetCurrentSystemRevisionFromFile(t *testing.T) {
	// Create a temp file to simulate /run/current-system/nixos-version
	dir := t.TempDir()
	versionPath := filepath.Join(dir, "nixos-version")

	tests := []struct {
		content string
		wantRev string
	}{
		{"25.11.20260203.e576e3c\n", "e576e3c"},
		{"1994-294a625\n", "294a625"},
		{"25.05.20250101.abcdef1234567890\n", "abcdef1"},
		{"no-hash", ""},
	}

	for _, tt := range tests {
		t.Run(tt.content, func(t *testing.T) {
			if err := os.WriteFile(versionPath, []byte(tt.content), 0644); err != nil {
				t.Fatal(err)
			}

			// We can't easily test the actual function without modifying the constant,
			// so we test the pattern extraction logic directly
			version := tt.content
			if len(version) > 0 && version[len(version)-1] == '\n' {
				version = version[:len(version)-1]
			}

			matches := revisionPattern.FindStringSubmatch(version)
			var rev string
			if matches != nil {
				rev = matches[1]
				if len(rev) > 7 {
					rev = rev[:7]
				}
			}

			if rev != tt.wantRev {
				t.Errorf("got revision %q, want %q", rev, tt.wantRev)
			}
		})
	}
}

func TestFlakeLocksUnmarshal(t *testing.T) {
	jsonData := `{
		"revision": "abc1234567890",
		"locks": {
			"nodes": {
				"nixpkgs": {
					"locked": {
						"lastModified": 1700000000,
						"rev": "def4567890123",
						"type": "github"
					}
				},
				"home-manager": {
					"locked": {
						"lastModified": 1699000000,
						"rev": "ghi7890123456",
						"type": "github"
					}
				},
				"root": {
					"inputs": {
						"nixpkgs": "nixpkgs",
						"home-manager": "home-manager"
					}
				}
			},
			"root": "root"
		}
	}`

	var data flakeMetadata
	if err := json.Unmarshal([]byte(jsonData), &data); err != nil {
		t.Fatal(err)
	}

	if data.Revision != "abc1234567890" {
		t.Errorf("expected revision abc1234567890, got %s", data.Revision)
	}

	if len(data.Locks.Nodes) != 3 {
		t.Errorf("expected 3 nodes, got %d", len(data.Locks.Nodes))
	}

	nixpkgs := data.Locks.Nodes["nixpkgs"]
	if nixpkgs.Locked == nil {
		t.Fatal("expected nixpkgs to have locked info")
	}
	if nixpkgs.Locked.LastModified != 1700000000 {
		t.Errorf("expected lastModified 1700000000, got %d", nixpkgs.Locked.LastModified)
	}
	if nixpkgs.Locked.Rev != "def4567890123" {
		t.Errorf("expected rev def4567890123, got %s", nixpkgs.Locked.Rev)
	}
	if nixpkgs.Locked.Type != "github" {
		t.Errorf("expected type github, got %s", nixpkgs.Locked.Type)
	}
}