// SPDX-License-Identifier: GPL-3.0-or-later

package config

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

// writeFiles creates each file under root, making directories as needed.
func writeFiles(t *testing.T, root string, files map[string]string) {
	t.Helper()
	for name, body := range files {
		p := filepath.Join(root, name)
		if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(p, []byte(body), 0o644); err != nil {
			t.Fatal(err)
		}
	}
}

func TestLoad(t *testing.T) {
	root := t.TempDir()
	writeFiles(t, root, map[string]string{
		"krino.conf":  `(include "a" "b") (defaults (min-age 5m))`,
		"dirs/a.conf": `(path "/tmp/a") (min-age 1m) (rule "r" (stop))`,
		"dirs/b.conf": `(path "/tmp/b") (rule "r" (stop))`,
	})
	main := filepath.Join(root, "krino.conf")
	cfg, errs := Load(main)
	if len(errs) > 0 {
		t.Fatal(errs)
	}
	if len(cfg.Dirs) != 2 || cfg.Dirs[0].Name != "a" || cfg.Dirs[1].Path != "/tmp/b" {
		t.Fatalf("dirs = %+v", cfg.Dirs)
	}
	if got := cfg.Resolved(cfg.Dirs[0]).MinAge; got != time.Minute {
		t.Errorf("a min-age = %v, want the directory's 1m", got)
	}
	if got := cfg.Resolved(cfg.Dirs[1]).MinAge; got != 5*time.Minute {
		t.Errorf("b min-age = %v, want the default 5m", got)
	}
	cfg, errs = Load(main, "b")
	if len(errs) > 0 || len(cfg.Dirs) != 1 || cfg.Dirs[0].Name != "b" {
		t.Fatalf("Load(b) = %+v, %v", cfg, errs)
	}
}

func TestLoadErrors(t *testing.T) {
	root := t.TempDir()
	main := filepath.Join(root, "krino.conf")
	cfg, errs := Load(main)
	if cfg != nil || len(errs) != 1 || errs[0].Error() != main+": not found; create it with: krino init" {
		t.Fatalf("missing main file: %v", errs)
	}
	writeFiles(t, root, map[string]string{"krino.conf": "(include \"gone\")\n"})
	_, errs = Load(main)
	want := fmt.Sprintf(`%s:1:10: included "gone", but %s does not exist; create it with: krino new gone PATH`,
		main, filepath.Join(root, "dirs", "gone.conf"))
	if len(errs) != 1 || errs[0].Error() != want {
		t.Fatalf("missing dir file:\n got  %v\n want %s", errs, want)
	}
	_, errs = Load(main, "other")
	if len(errs) != 1 || !strings.HasSuffix(errs[0].Error(), `: "other" is not in include`) {
		t.Fatalf("unknown name: %v", errs)
	}
}

// TestLoadSyntaxErrorStopsAtOneDiag is item C: a krino.conf that fails to
// parse must report only the syntax error, not also "not in include" for
// names the caller asked for.
func TestLoadSyntaxErrorStopsAtOneDiag(t *testing.T) {
	root := t.TempDir()
	writeFiles(t, root, map[string]string{"krino.conf": `(include "dl"`})
	main := filepath.Join(root, "krino.conf")
	_, errs := Load(main, "dl")
	if len(errs) != 1 {
		t.Fatalf("errs = %v, want exactly one diag", errs)
	}
	want := fmt.Sprintf(`%s:1:1: "(" never closed: (include "dl")`, main)
	if errs[0].Error() != want {
		t.Fatalf("got  %s\nwant %s", errs[0], want)
	}
}

func TestDefaultFileAndLogFile(t *testing.T) {
	t.Setenv("XDG_CONFIG_HOME", "/conf")
	t.Setenv("XDG_STATE_HOME", "/state")
	if got := DefaultFile(); got != "/conf/krino/krino.conf" {
		t.Errorf("DefaultFile() = %q", got)
	}
	c := &Config{Main: &Main{}}
	if got := c.LogFile(); got != "/state/krino/krino.log" {
		t.Errorf("LogFile() = %q", got)
	}
	c.Main.Log = "/x.log"
	if got := c.LogFile(); got != "/x.log" {
		t.Errorf("LogFile() = %q", got)
	}
}

func TestLockFile(t *testing.T) {
	h := t.TempDir()
	t.Setenv("HOME", h)
	t.Setenv("XDG_STATE_HOME", "")
	c := &Config{}
	want := filepath.Join(h, ".local", "state", "krino", "dl.lock")
	if got := c.LockFile("dl"); got != want {
		t.Errorf("LockFile = %q, want %q", got, want)
	}
}

// TestLoadWithOverriddenText: LoadWith reads the text the caller supplies
// instead of a file's own, so an editor can check what it has not saved yet
// (GUI design §1.3); the files on disk are neither read differently nor
// changed.
func TestLoadWithOverriddenText(t *testing.T) {
	h := t.TempDir()
	t.Setenv("HOME", h)
	main := filepath.Join(h, "krino.conf")
	if err := os.MkdirAll(filepath.Join(h, "dirs"), 0o755); err != nil {
		t.Fatal(err)
	}
	os.WriteFile(main, []byte("(include \"dl\")\n"), 0o644)
	os.WriteFile(filepath.Join(h, "dirs", "dl.conf"), []byte("(path \"/tmp\")\n"), 0o644)

	over := map[string][]byte{filepath.Join(h, "dirs", "dl.conf"): []byte("(path \"/tmp\")\n(rule \"r\" (move \"Out\"))\n")}
	cfg, errs := LoadWith(main, over)
	if len(errs) > 0 || len(cfg.Dirs) != 1 || len(cfg.Dirs[0].Rules) != 1 {
		t.Fatalf("overridden text not used: %v %+v", errs, cfg.Dirs)
	}
	if _, errs := LoadWith(main, map[string][]byte{main: []byte("(include \"dl\"")}); len(errs) == 0 {
		t.Error("a mistake in the overridden main file was not reported")
	}
	if cfg, errs := Load(main); len(errs) > 0 || len(cfg.Dirs[0].Rules) != 0 {
		t.Errorf("the files on disk were read differently: %v %+v", errs, cfg.Dirs)
	}
}