package mite

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"time"
)

type APIClient struct {
	domain string
	apiKey string
}

func NewClient(domain, apikey string) APIClient {
	return APIClient{
		domain: domain,
		apiKey: apikey,
	}
}

type APIObject interface {
	GetID() int
	GetName() string
}

//	https://demo.mite.de/
//curl -H 'X-MiteApiKey: YOUR_API_KEY' https://demo.mite.de/projects.json

type APIProjects []ProjectHolder
type ProjectHolder struct {
	Project Project `json:"project"`
}
type Projects []Project
type Project struct {
	Budget       int       `json:"budget"`
	BudgetType   string    `json:"budget_type"`
	CreatedAt    time.Time `json:"created_at"`
	CustomerID   int       `json:"customer_id"`
	HourlyRate   int       `json:"hourly_rate"`
	ID           int       `json:"id"`
	Name         string    `json:"name"`
	Note         string    `json:"note"`
	UpdatedAt    time.Time `json:"updated_at"`
	Archived     bool      `json:"archived"`
	CustomerName string    `json:"customer_name"`
}

func (p Project) String() string {
	return fmt.Sprintf("%d: %s (%s)", p.ID, p.Name, p.CustomerName)
}
func (p Project) GetID() int { return p.ID }
func (p Project) GetName() string {
	return p.Name + " (" + p.CustomerName + ")"
}

func (a APIClient) GetProjects() (Projects, error) {
	// GET /projects.json
	p := APIProjects{}
	err := a.get("/projects.json", &p)
	if err != nil {
		return nil, err
	}

	out := Projects{}
	for i := range p {
		out = append(out, p[i].Project)
	}
	return out, nil
}

type apiCustomers []customerHolder
type customerHolder struct {
	Customer Customer `json:"customer"`
}

type Customers []Customer
type Customer struct {
	CreatedAt             time.Time `json:"created_at"`
	HourlyRate            int       `json:"hourly_rate"`
	ID                    int       `json:"id"`
	Name                  string    `json:"name"`
	Note                  string    `json:"note"`
	UpdatedAt             time.Time `json:"updated_at"`
	Archived              bool      `json:"archived"`
	ActiveHourlyRate      string    `json:"active_hourly_rate"`
	HourlyRatesPerService []struct {
		ServiceID  int `json:"service_id"`
		HourlyRate int `json:"hourly_rate"`
	} `json:"hourly_rates_per_service"`
}

func (c Customer) String() string {
	return fmt.Sprintf("%d: %s", c.ID, c.Name)
}
func (c Customer) GetID() int      { return c.ID }
func (c Customer) GetName() string { return c.Name }

func (a APIClient) GetCustomers() (Customers, error) {
	// GET /customers.json
	p := apiCustomers{}
	err := a.get("/customers.json", &p)
	if err != nil {
		return nil, err
	}

	out := Customers{}
	for i := range p {
		out = append(out, p[i].Customer)
	}
	return out, nil
}

type apiServices []serviceHolder
type serviceHolder struct {
	Service Service `json:"service"`
}
type Services []Service
type Service struct {
	Billable   bool      `json:"billable"`
	CreatedAt  time.Time `json:"created_at"`
	HourlyRate int       `json:"hourly_rate"`
	ID         int       `json:"id"`
	Name       string    `json:"name"`
	Note       string    `json:"note"`
	UpdatedAt  time.Time `json:"updated_at"`
	Archived   bool      `json:"archived"`
}

func (s Service) String() string {
	return fmt.Sprintf("%d: %s", s.ID, s.Name)
}
func (s Service) GetID() int { return s.ID }
func (s Service) GetName() string {
	prefix := "💰"
	if !s.Billable {
		prefix = "☮️"
	}
	return prefix + " " + s.Name

}

func (a APIClient) GetServices() (Services, error) {
	// GET /services.json
	p := apiServices{}
	err := a.get("/services.json", &p)
	if err != nil {
		return nil, err
	}

	out := Services{}
	for i := range p {
		out = append(out, p[i].Service)
	}
	return out, nil
}

type apiTimeEntry []timeEntryHolder
type timeEntryHolder struct {
	TimeEntry TimeEntry `json:"time_entry"`
}
type TimeEntries []TimeEntry
type TimeEntry struct {
	Billable     bool        `json:"billable"`
	CreatedAt    time.Time   `json:"created_at"`
	DateAt       string      `json:"date_at"`
	ID           int         `json:"id"`
	Locked       bool        `json:"locked"`
	Minutes      int         `json:"minutes"`
	StartedTime  interface{} `json:"started_time"`
	ProjectID    int         `json:"project_id"`
	Revenue      float64     `json:"revenue"`
	HourlyRate   int         `json:"hourly_rate"`
	ServiceID    int         `json:"service_id"`
	UpdatedAt    time.Time   `json:"updated_at"`
	UserID       int         `json:"user_id"`
	Note         string      `json:"note"`
	UserName     string      `json:"user_name"`
	CustomerID   int         `json:"customer_id"`
	CustomerName string      `json:"customer_name"`
	ProjectName  string      `json:"project_name"`
	ServiceName  string      `json:"service_name"`
}

func (t TimeEntry) String() string {
	return fmt.Sprintf("%d: %s - %s for %dm", t.ID, t.DateAt, t.CustomerName, t.Minutes)
}

func (te TimeEntries) ByDate(t time.Time) TimeEntries {
	ymd := t.Format(time.DateOnly)
	out := TimeEntries{}
	for i := range te {
		if te[i].DateAt == ymd {
			out = append(out, te[i])
		}
	}
	return out
}

func (te TimeEntries) MinutesByDate() map[string]int {
	out := map[string]int{}
	for i := range te {
		dt := te[i].DateAt
		if _, ok := out[dt]; ok {
			out[dt] += te[i].Minutes
		} else {
			out[dt] = te[i].Minutes
		}
	}
	return out
}

// GetTimeEntries the "to" time is inclusive - ie time entries on that date are included
func (a APIClient) GetTimeEntries(from, to time.Time) (TimeEntries, error) {
	// GET /...  YYYY-MM-DD from= to=
	p := apiTimeEntry{}
	u := fmt.Sprintf("/time_entries.json?from=%s&to=%s", from.Format(time.DateOnly), to.Format(time.DateOnly))

	err := a.get(u, &p)
	if err != nil {
		return nil, err
	}

	out := TimeEntries{}
	for i := range p {
		out = append(out, p[i].TimeEntry)
	}
	return out, nil
}

type requestAddTimeEntry struct {
	RequestTimeEntryHolder struct {
		DateAt    string `json:"date_at"`
		Minutes   int    `json:"minutes"`
		ProjectID int    `json:"project_id,omitempty"`
		ServiceID int    `json:"service_id,omitempty"`
		Note      string `json:"note"`
	} `json:"time_entry"`
}

type apiPostTimeEntry timeEntryHolder

func (a APIClient) AddTimeEntry(date string, minutes int, notes string, projectId, serviceId int) (int, error) {
	// POST /time_entries.json
	// {
	// 	"time_entry": {
	// 	   "date_at": "2015-9-15",
	// 	   "minutes": 185,
	// 	   "service_id": 243
	// 	}
	//  }
	req := requestAddTimeEntry{}
	req.RequestTimeEntryHolder.DateAt = date
	req.RequestTimeEntryHolder.Minutes = minutes
	req.RequestTimeEntryHolder.Note = notes
	req.RequestTimeEntryHolder.ProjectID = projectId
	req.RequestTimeEntryHolder.ServiceID = serviceId

	res := apiPostTimeEntry{}

	err := a.post("/time_entries.json", req, &res)
	return res.TimeEntry.ID, err
}

type apiTimeTrackerEntry struct {
	TimeTrackerHolder timeTrackerHolder `json:"tracker"`
}

type timeTrackerHolder struct {
	TrackingTimeEntry *TrackingTimeEntry `json:"tracking_time_entry"`
	StoppedTimeEntry  *StoppedTimeEntry  `json:"stopped_time_entry"`
}

type TrackingTimeEntry struct {
	ID      int       `json:"id"`
	Minutes int       `json:"minutes"`
	Since   time.Time `json:"since"`
}

type StoppedTimeEntry struct {
	ID      int `json:"id"`
	Minutes int `json:"minutes"`
}

// {
// 	"tracker": {
// 	  "tracking_time_entry": {
// 		"id": 36135322,
// 		"minutes": 0,
// 		"since": "2015-10-15T17:33:52+02:00"
// 	  },
// 	 "stopped_time_entry": {
// 		"id": 36134329,
// 		"minutes": 46
// 	  }
// 	}
//   }

// {
// 	"tracker": {
// 	  "tracking_time_entry": {
// 		"id": 36135321,
// 		"minutes": 247,
// 		"since": "2015-10-15T17:05:04+02:00"
// 	  }
// 	}
//   }

var ErrNoTracker = errors.New("no time tracker running")

// GetTimeTracker gets the current running time tracker. If no tracker is
// running, the error returned will be ErrNoTracker
func (a APIClient) GetTimeTracker() (TrackingTimeEntry, error) {
	r := apiTimeTrackerEntry{}
	err := a.get("/tracker.json", &r)
	if err != nil {
		return TrackingTimeEntry{}, err
	}
	if r.TimeTrackerHolder.TrackingTimeEntry == nil {
		return TrackingTimeEntry{}, ErrNoTracker
	}
	return *r.TimeTrackerHolder.TrackingTimeEntry, nil
}

func (a APIClient) StartTimeTracker(id int) (TrackingTimeEntry, *StoppedTimeEntry, error) {
	url := fmt.Sprintf("/tracker/%d.json", id)
	r := apiTimeTrackerEntry{}

	err := a.patch(url, &r)

	if err != nil {
		return TrackingTimeEntry{}, nil, err
	}
	if r.TimeTrackerHolder.TrackingTimeEntry == nil {
		// I don't think this should happen, the patch should have been a 404?

		panic(fmt.Sprintf("unexpected failure to find a tracking entry in a successful PATCH\n%#v", r.TimeTrackerHolder))
	}
	return *r.TimeTrackerHolder.TrackingTimeEntry, r.TimeTrackerHolder.StoppedTimeEntry, nil
}

func (a APIClient) StopTimeTracker(id int) (StoppedTimeEntry, error) {
	url := fmt.Sprintf("/tracker/%d.json", id)
	r := apiTimeTrackerEntry{}

	err := a.delete(url, &r)

	if err != nil {
		return StoppedTimeEntry{}, err
	}
	if r.TimeTrackerHolder.StoppedTimeEntry == nil {
		// I don't think this should happen, the patch should have been a 404?

		panic(fmt.Sprintf("unexpected failure to find a tracking entry in a successful DELETE\n%#v", r.TimeTrackerHolder))
	}
	return *r.TimeTrackerHolder.StoppedTimeEntry, nil
}

func (a APIClient) delete(path string, data any) error {

	req, err := http.NewRequest("DELETE", baseurl(a.domain, path), nil)
	if err != nil {
		return err
	}
	req.Header.Add("X-MiteApiKey", a.apiKey)
	resp, err := http.DefaultClient.Do(req)

	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 300 {
		return fmt.Errorf("expected 2XX, got %d", resp.StatusCode)
	}
	err = json.NewDecoder(resp.Body).Decode(&data)
	if err != nil {
		return err
	}
	return nil
}

func (a APIClient) patch(path string, data any) error {

	req, err := http.NewRequest("PATCH", baseurl(a.domain, path), nil)
	if err != nil {
		return err
	}
	req.Header.Add("X-MiteApiKey", a.apiKey)
	resp, err := http.DefaultClient.Do(req)

	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 300 {
		return fmt.Errorf("expected 2XX, got %d", resp.StatusCode)
	}
	err = json.NewDecoder(resp.Body).Decode(&data)
	if err != nil {
		return err
	}
	return nil
}

func (a APIClient) post(path string, dataIn any, dataOut any) error {

	b, err := json.Marshal(dataIn)
	if err != nil {
		return err
	}

	req, err := http.NewRequest("POST", baseurl(a.domain, path), bytes.NewBuffer(b))
	if err != nil {
		return err
	}
	req.Header.Add("X-MiteApiKey", a.apiKey)
	req.Header.Add("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)

	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 300 {
		return fmt.Errorf("expected 2XX, got %d", resp.StatusCode)
	}

	err = json.NewDecoder(resp.Body).Decode(&dataOut)
	if err != nil {
		return err
	}

	return nil

}

func (a APIClient) get(path string, data any) error {
	req, err := http.NewRequest("GET", baseurl(a.domain, path), nil)
	if err != nil {
		return err
	}
	req.Header.Add("X-MiteApiKey", a.apiKey)
	resp, err := http.DefaultClient.Do(req)

	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 300 {
		return fmt.Errorf("expected 2XX, got %d", resp.StatusCode)
	}
	err = json.NewDecoder(resp.Body).Decode(&data)
	if err != nil {
		return err
	}
	return nil
}

func baseurl(domain, path string) string {
	return fmt.Sprintf("https://%s.mite.de/%s", domain, path)
}