package config

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"reflect"
	"slices"
	"strings"

	"github.com/spf13/viper"

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

// printEnv logs each JOBSEARCH* environment variable at debug level. On a
// terminal it logs one line and prints the variables under it as
// "name=value" lines; elsewhere each variable is a log entry of its own.
func printEnv() {
	logger := slog.Default()
	terminal := logging.WritesToTerminal(logger.Handler())
	if terminal && !logger.Enabled(context.Background(), slog.LevelDebug) {
		return
	}

	var variables []string
	for _, variable := range os.Environ() {
		if strings.HasPrefix(variable, EnvPrefix) {
			variables = append(variables, variable)
		}
	}
	slices.Sort(variables)

	if terminal {
		logger.Debug("environment variables", "count", len(variables))
	}
	for _, variable := range variables {
		if terminal {
			logging.PrintToTerminal("\t" + variable)
			continue
		}
		name, value, _ := strings.Cut(variable, "=")
		logger.Debug("environment variable", "name", name, "value", value)
	}
}

// printLoadedConfig logs every key set by the config file or an environment
// variable (see isExplicitlySet), with its value and type, at debug level. On
// a terminal it logs one line and prints the values under it as
// "key = value <type>" lines; elsewhere each value is a log entry of its own.
func printLoadedConfig() {
	logger := slog.Default()
	terminal := logging.WritesToTerminal(logger.Handler())
	if terminal && !logger.Enabled(context.Background(), slog.LevelDebug) {
		return
	}

	var keys []string
	for _, key := range viper.AllKeys() {
		if isExplicitlySet(key) {
			keys = append(keys, key)
		}
	}

	if terminal {
		logger.Debug("loaded config values", "count", len(keys))
	}
	for _, key := range keys {
		value := viper.Get(key)
		kind := reflect.TypeOf(value).Kind().String()
		if terminal {
			logging.PrintToTerminal(
				fmt.Sprintf("\t%s = %#v <%s>", key, value, kind),
			)
			continue
		}
		logger.Debug(
			"loaded config value",
			"key", key,
			"value", value,
			"type", kind,
		)
	}
}

// printConfig logs conf at debug level.
func printConfig(conf JobSearchConfig) {
	conf.PrintLog(slog.LevelDebug)
}