package common

import (
	"encoding/json"
	"fmt"
	"math"
)

type AhaHelpLevel struct {
	BuffID          uint32  `json:"BuffID"`
	ProgressPercent float64 `json:"ProgressPercent"`
	BuffLevel       uint32  `json:"BuffLevel"`
}

// The supplied table selects the support buff; progress thresholds are metadata,
// not a fabricated dynamic-value key sent to the Client.
func LoadAhaHelpLevels() ([]AhaHelpLevel, error) {
	raw, err := ReadResourceFile("resources/AhaHelpConfig.json")
	if err != nil {
		return nil, err
	}
	var config struct {
		Source string         `json:"source"`
		Levels []AhaHelpLevel `json:"levels"`
	}
	if err = json.Unmarshal(raw, &config); err != nil {
		return nil, err
	}
	if config.Source == "" || len(config.Levels) == 0 {
		return nil, fmt.Errorf("Aha help table has no provenance or levels")
	}
	seen := map[uint32]bool{}
	for _, level := range config.Levels {
		if level.BuffID == 0 || level.BuffLevel == 0 || seen[level.BuffLevel] || math.IsNaN(level.ProgressPercent) || level.ProgressPercent < 0 || level.ProgressPercent > 1 {
			return nil, fmt.Errorf("invalid Aha help level")
		}
		seen[level.BuffLevel] = true
	}
	return config.Levels, nil
}

// nil preserves the existing FreeSR switch. Explicit zero means disabled.
func ReadAhaHelpLevel() (*uint32, error) {
	root, err := readCurrencyWarsPersistentRoot()
	if err != nil {
		return nil, err
	}
	raw, ok := root["aha_help_level"]
	if !ok {
		return nil, nil
	}
	var level *uint32
	if err = json.Unmarshal(raw, &level); err != nil {
		return nil, err
	}
	return level, nil
}

func SaveAhaHelpLevel(level *uint32) error {
	levels, err := LoadAhaHelpLevels()
	if err != nil {
		return err
	}
	if level != nil && *level != 0 {
		found := false
		for _, row := range levels {
			found = found || row.BuffLevel == *level
		}
		if !found {
			return fmt.Errorf("Aha help level is not in the configured table")
		}
	}
	persistentWriteMu.Lock()
	defer persistentWriteMu.Unlock()
	unlock, err := lockPersistentFile()
	if err != nil {
		return err
	}
	defer unlock()
	root, err := readCurrencyWarsPersistentRoot()
	if err != nil {
		return err
	}
	if level == nil {
		delete(root, "aha_help_level")
	} else {
		root["aha_help_level"], err = json.Marshal(*level)
	}
	if err != nil {
		return err
	}
	return writeJSONAtomic("persistent", root)
}