package config

import (
	"strings"
	"testing"

	"github.com/spf13/cobra"
	"go.yaml.in/yaml/v3"

	"git.avsdev.uk/Go/job-search/internal/cli"
	"git.avsdev.uk/Go/job-search/internal/cli/cmdtest"
)

// These tests run the config commands as a user would, through a root
// command like job-search's (see cmdtest).

const appConfig = `logging:
  level: info
sources:
  sleeper:
    interval: 2m
`

func newRoot() *cobra.Command {
	opts := &cli.Options{}
	return cmdtest.NewRoot(opts, NewCommand(opts))
}

func run(t *testing.T, args ...string) (string, error) {
	t.Helper()
	return cmdtest.Run(t, newRoot, "", args...)
}

func mustRun(t *testing.T, args ...string) string {
	t.Helper()
	return cmdtest.MustRun(t, newRoot, args...)
}

// fileSettings returns the settings in the YAML file at path, flattened to
// dotted keys.
func fileSettings(t *testing.T, path string) map[string]any {
	t.Helper()
	var nested map[string]any
	if err := yaml.Unmarshal(
		[]byte(cmdtest.ReadFile(t, path)), &nested,
	); err != nil {
		t.Fatal(err)
	}

	flat := map[string]any{}
	var walk func(prefix string, m map[string]any)
	walk = func(prefix string, m map[string]any) {
		for k, v := range m {
			if sub, ok := v.(map[string]any); ok {
				walk(prefix+k+".", sub)
			} else {
				flat[prefix+k] = v
			}
		}
	}
	walk("", nested)

	return flat
}

func TestConfigShow(t *testing.T) {
	cmdtest.Setup(t, appConfig)

	out := mustRun(t, "config", "show")
	cmdtest.Contains(
		t,
		out,
		"logging.level = info <string>",
		"sources.sleeper.interval = 2m0s <string>",
	)

	// Keys are listed in order, the same every time.
	if again := mustRun(t, "config", "show"); again != out {
		t.Errorf(
			"config show output changed between runs:\n%s\n---\n%s", out, again,
		)
	}

	database := strings.Index(out, "database.file")
	logging := strings.Index(out, "logging.level")
	if database > logging {
		t.Errorf("keys not sorted:\n%s", out)
	}

	out = mustRun(t, "config", "show", "--json")
	cmdtest.Contains(t, out, `"level": "info"`, `"interval": "2m0s"`)

	out = mustRun(t, "config", "show", "--yaml")
	cmdtest.Contains(t, out, "level: info", "interval: 2m0s")
}

func TestConfigGet(t *testing.T) {
	cmdtest.Setup(t, appConfig)

	for _, tt := range []struct {
		key, want string
	}{
		{"logging.level", "info <string>"},
		{"sources.sleeper.interval", "2m0s <string>"},
		{"sources.sleeper.enabled", "false <bool>"},
	} {
		t.Run(tt.key, func(t *testing.T) {
			cmdtest.Contains(t, mustRun(t, "config", "get", tt.key), tt.want)
		})
	}

	if _, err := run(t, "config", "get", "no.such.key"); err == nil {
		t.Error("get of an unknown key succeeded")
	}
	if _, err := run(t, "config", "get"); err == nil {
		t.Error("get without a key succeeded")
	}
}

func TestConfigSet(t *testing.T) {
	cmdtest.Setup(t, appConfig)

	out := mustRun(t, "config", "set", "logging.level", "debug")
	cmdtest.Contains(t, out, "logging.level = debug <string>")
	cmdtest.Contains(
		t, mustRun(t, "config", "get", "logging.level"), "debug <string>",
	)

	out = mustRun(t, "config", "set", "sources.sleeper.enabled", "true")
	cmdtest.Contains(t, out, "sources.sleeper.enabled = true <bool>")

	// Durations are stored as given out, e.g. 5m0s.
	out = mustRun(t, "config", "set", "sources.sleeper.interval", "5m")
	cmdtest.Contains(t, out, "sources.sleeper.interval = 5m0s <string>")

	// Only the settings the file had, plus those set, are written: no
	// defaults.
	want := map[string]any{
		"logging.level":            "debug",
		"sources.sleeper.enabled":  true,
		"sources.sleeper.interval": "5m0s",
	}
	if got := fileSettings(t, "config.yaml"); !equalSettings(got, want) {
		t.Errorf("config.yaml settings = %v; want %v", got, want)
	}

	for _, args := range [][]string{
		{"config", "set", "logging.level", "loud"},          // rejected by validation
		{"config", "set", "sources.sleeper.enabled", "yes"}, // not a bool
		{"config", "set", "sources.sleeper.interval", "soon"},
		{"config", "set", "no.such.key", "1"},
		{"config", "set", "logging.level"}, // no value, no --unset
	} {
		if _, err := run(t, args...); err == nil {
			t.Errorf("%v succeeded", args)
		}
	}
	if got := fileSettings(t, "config.yaml"); !equalSettings(got, want) {
		t.Errorf("failed sets changed config.yaml: %v", got)
	}
}

func equalSettings(a, b map[string]any) bool {
	if len(a) != len(b) {
		return false
	}
	for k, v := range a {
		if b[k] != v {
			return false
		}
	}
	return true
}

func TestConfigSetUnset(t *testing.T) {
	cmdtest.Setup(t, appConfig)

	mustRun(t, "config", "set", "--unset", "sources.sleeper.interval")

	// Only the unset key is gone: no defaults are written in its place.
	want := map[string]any{"logging.level": "info"}
	if got := fileSettings(t, "config.yaml"); !equalSettings(got, want) {
		t.Errorf("config.yaml settings = %v; want %v", got, want)
	}

	// Back to the default.
	cmdtest.Contains(
		t,
		mustRun(t, "config", "get", "sources.sleeper.interval"),
		"10m0s <string>",
	)
}

func TestConfigSetWithoutConfigFile(t *testing.T) {
	cmdtest.Setup(t, "")
	_, err := run(t, "config", "set", "logging.level", "debug")
	cmdtest.ErrContains(t, err, "no configuration file exists")
}

func TestConfigInit(t *testing.T) {
	cmdtest.Setup(t, "")

	out := mustRun(t, "config", "init", "./new.yaml")
	cmdtest.Contains(t, out, "writing default configuration to file: ./new.yaml")
	cmdtest.Contains(
		t, cmdtest.ReadFile(t, "new.yaml"), "level: warn", "interval: 10m0s",
	)

	_, err := run(t, "config", "init", "./new.yaml")
	cmdtest.ErrContains(t, err, "already exists")

	if _, err := run(t, "config", "init", "a.yaml", "b.yaml"); err == nil {
		t.Error("init with two paths succeeded")
	}
}

// With no path (or a blank one), init searches the default locations. The
// working directory is one, so its config.yaml is found. (Not finding one
// would write to /etc/job-search, which a test can't do.)
func TestConfigInitDefaultLocations(t *testing.T) {
	cmdtest.Setup(t, appConfig)
	for _, args := range [][]string{
		{"config", "init"},
		{"config", "init", "  "},
	} {
		t.Run(strings.Join(args, " "), func(t *testing.T) {
			_, err := run(t, args...)
			cmdtest.ErrContains(t, err, "already exists")
		})
	}
}

// init takes the path as an argument, so --config isn't shown in its help.
func TestConfigInitHelpHidesConfigFlag(t *testing.T) {
	cmdtest.Setup(t, "")
	out := mustRun(t, "config", "init", "--help")
	cmdtest.Contains(t, out, "init [config_path]", "--debug")
	if strings.Contains(out, "--config") {
		t.Errorf("init help shows --config:\n%s", out)
	}
}