package config

import (
	"bytes"
	"text/template"

	"github.com/spf13/viper"
	tmos "github.com/tendermint/tendermint/libs/os"
)

const defaultConfigTemplate = `# This is a TOML config file.
# For more information, see https://github.com/toml-lang/toml

##### main base config options #####

# The minimum gas prices a validator is willing to accept for processing a
# transaction. A transaction's fees must meet the minimum of any denomination
# specified in this config (e.g. 0.25token1;0.0001token2).
minimum-gas-prices = "{{ .BaseConfig.MinGasPrices }}"

# HaltHeight contains a non-zero block height at which a node will gracefully
# halt and shutdown that can be used to assist upgrades and testing.
#
# Note: Commitment of state will be attempted on the corresponding block.
halt-height = {{ .BaseConfig.HaltHeight }}

# HaltTime contains a non-zero minimum block time (in Unix seconds) at which
# a node will gracefully halt and shutdown that can be used to assist upgrades
# and testing.
#
# Note: Commitment of state will be attempted on the corresponding block.
halt-time = {{ .BaseConfig.HaltTime }}

# InterBlockCache enables inter-block caching.
inter-block-cache = {{ .BaseConfig.InterBlockCache }}

# Pruning sets the pruning strategy: syncable, nothing, everything
# syncable: only those states not needed for state syncing will be deleted (keeps last 100 + every 10000th)
# nothing: all historic states will be saved, nothing will be deleted (i.e. archiving node)
# everything: all saved states will be deleted, storing only the current state
pruning = "{{ .BaseConfig.Pruning }}"
`

var configTemplate *template.Template

func init() {
	var err error
	tmpl := template.New("appConfigFileTemplate")
	if configTemplate, err = tmpl.Parse(defaultConfigTemplate); err != nil {
		panic(err)
	}
}

// ParseConfig retrieves the default environment configuration for the
// application.
func ParseConfig() (*Config, error) {
	conf := DefaultConfig()
	err := viper.Unmarshal(conf)
	return conf, err
}

// WriteConfigFile renders config using the template and writes it to
// configFilePath.
func WriteConfigFile(configFilePath string, config *Config) {
	var buffer bytes.Buffer

	if err := configTemplate.Execute(&buffer, config); err != nil {
		panic(err)
	}

	tmos.MustWriteFile(configFilePath, buffer.Bytes(), 0644)
}