// 2020 Rackspace, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.

package log

import (
	"fmt"
	"strings"

	"github.com/labstack/gommon/color"
)

const (
	// ErrorLvl: failure happened ans should be reviewed.
	ErrorLvl = iota

	// WarnLvl: non-critical; should be reviewed.
	WarnLvl

	// InfoLvl level is a general entry about what's going on inside the application
	InfoLvl

	// DebugLvl level is only enabled when debugging. Very verbose logging.
	DebugLvl

	// TraceLvl level designates finer-grained informational events than the Debug.
	TraceLvl
)

// Print function will utilize logrus to print the output to terminal for the envLog type.
func (e Entry) Print(minimumLevel uint32) {
	if e.Type <= minimumLevel {
		fmt.Println(e.ToTerminal())
	}
}

// String method will return a string format of the LogEntry struct
func (e Entry) String() string {
	if e.Message != "" {
		e.Message = ":" + e.Message
	}
	return fmt.Sprintf("[%s] %s%s", e.ID, e.Func, e.Message)
}

// ToTerminal method will return a string format of the LogEntry struct
func (e Entry) ToTerminal() string {
	if e.Message != "" {
		e.Message = ":" + e.Message
	}
	prefix := "UNKN"
	switch e.Type {
	case ErrorLvl:
		prefix = color.Red("ERRO")
	case WarnLvl:
		prefix = color.Yellow("WARN")
	case InfoLvl:
		prefix = color.Cyan("INFO")
	case DebugLvl:
		prefix = color.Magenta("DEBU")
	case TraceLvl:
		prefix = color.White("TRAC")
	}
	return fmt.Sprintf("%s: [%s] %s%s", prefix, color.Green(e.ID), color.Blue(e.Func), e.Message)
}

type (
	// LogEntry struct defines a type of log received from processing
	// gathering and changes to environment manager
	Entry struct {
		Type    uint32 `json:"-"`
		Func    string `json:"action"`
		ID      string `json:"id"`
		Message string `json:"message"`
	}

	// Collector is the type that gets initialized for this log package.
	Collector struct {
		Logs   []Entry  `json:"log_entries"`
		Errors []string `json:"errors"`
	}
)

// Init is a helper method to create a new empty collector
func Init() *Collector {
	return &Collector{
		Logs:   make([]Entry, 0),
		Errors: make([]string, 0),
	}
}

// Log is a helper method attached to the Collector pointer receiver that is used to append
// on an additional log message to the Collector client.
func (c *Collector) Log(state uint32, fn string, id interface{}, messages ...string) {
	if c.Logs == nil {
		c.Logs = make([]Entry, 0)
	}
	c.Logs = append(c.Logs, Entry{
		Type:    state,
		Func:    fn,
		ID:      fmt.Sprintf("%v", id),
		Message: strings.Join(messages, ":"),
	})
}

// Error is a wrapper method to add the error message onto the
// LogEntries
func (c *Collector) Error(f string, id interface{}, err error) {
	if c.Errors == nil {
		c.Errors = make([]string, 0)
	}
	c.Errors = append(c.Errors, fmt.Sprintf("[%v] %s=%s", id, f, err))
}

// Warn is a helper method that will append a log message on with a level to Warn
func (c *Collector) Warn(fn string, id interface{}, messages ...string) {
	c.Log(WarnLvl, fn, id, messages...)
}

// Info is a helper method that will append a log message on with a level to Info
func (c *Collector) Info(fn string, id interface{}, messages ...string) {
	c.Log(InfoLvl, fn, id, messages...)
}

// Debug is a helper method that will append a log message on with a level to Debug
func (c *Collector) Debug(fn string, id interface{}, messages ...string) {
	c.Log(DebugLvl, fn, id, messages...)
}

// Trace is a helper method that will append a log message on with a level to Trace
func (c *Collector) Trace(fn string, id interface{}, messages ...string) {
	c.Log(TraceLvl, fn, id, messages...)
}