package main

/*
   This file is part of taler-dashboard
   Copyright (C) 2023 Özgür Kesim

   taler-dashboard is free software; you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published by the
   Free Software Foundation; either version 3, or (at your option) any later
   version.

   taler-dashboard is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public
   License for more details.

   You can receive a copy of the GNU Affero General Public License from
   <http://www.gnu.org/licenses/>

   @author Özgür Kesim <oec-taler@kesim.org>
*/

import (
	"log"
	"sort"
	"strings"
	"time"
)

type Issues []Issue

type Issue struct {
	Id              uint32
	Summary         string
	Description     string
	Project         KeyVal
	Category        KeyVal
	TargetVersion   KeyVal `json:"target_version"`
	Reporter        KeyVal
	Handler         KeyVal
	Status          KeyVal
	Resolution      KeyVal
	ViewState       KeyVal `json:"view_state"`
	Priority        KeyVal
	Severity        KeyVal
	Reproducibility KeyVal
	Sticky          bool
	CreatedAt       time.Time `json:"created_at"`
	UpdatedAt       time.Time `json:"updated_at"`
	Notes           []Note
	Relationships   []Relationship
	Tags            []KeyVal
	History         []Change
}

type KeyVal struct {
	Id    uint32
	Name  string
	Label string `json:",omitempty"`
	Color string `json:",omitempty"`
}

type Note struct {
	Id          uint32
	Text        string
	Reporter    KeyVal
	ViewState   KeyVal `json:"view_state"`
	Attachments []Attachment
	Typ         string    `json:"type"`
	CreatedAt   time.Time `json:"created_at"`
	UpdatedAt   time.Time `json:"created_at"`
}

type Attachment struct {
	Name    string
	Content []byte
}

type Relationship struct {
	Id    uint32
	Typ   KeyVal `json:"type"`
	Issue struct {
		Id         uint32
		Summary    string
		Status     KeyVal
		Resolution KeyVal
		Handler    KeyVal
	}
}

type Change struct {
	CreatedAt time.Time `json:"created_at"`
	Message   string
	User      KeyVal
	Typ       KeyVal `json:"type"`
	Note      struct{ id int32 }
}

type ByCategory []Issue

func (b ByCategory) Len() int { return len(b) }
func (b ByCategory) Less(i, j int) bool {
	return strings.Compare(b[i].Category.Name, b[j].Category.Name) < 0
}
func (b ByCategory) Swap(i, j int) { b[i], b[j] = b[j], b[i] }

type ByAssignment []Issue

func (b ByAssignment) Len() int { return len(b) }
func (b ByAssignment) Less(i, j int) bool {
	return strings.Compare(b[i].Handler.Name, b[j].Handler.Name) < 0
}
func (b ByAssignment) Swap(i, j int) { b[i], b[j] = b[j], b[i] }

type ById []Issue

func (b ById) Len() int           { return len(b) }
func (b ById) Less(i, j int) bool { return b[i].Id < b[j].Id }
func (b ById) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }

type ByTarget []Issue

func (b ByTarget) Len() int { return len(b) }
func (b ByTarget) Less(i, j int) bool {
	return strings.Compare(b[i].TargetVersion.Name, b[j].TargetVersion.Name) < 0
}
func (b ByTarget) Swap(i, j int) { b[i], b[j] = b[j], b[i] }

type ByHandlerAndId []Issue

func (b ByHandlerAndId) Len() int { return len(b) }
func (b ByHandlerAndId) Less(i, j int) bool {
	if (b[i].Handler.Name == "") == (b[j].Handler.Name == "") {
		return b[i].Id < b[j].Id
	} else if b[i].Handler.Name == "" {
		return true
	}
	return false
}
func (b ByHandlerAndId) Swap(i, j int) { b[i], b[j] = b[j], b[i] }

func (i Issues) Tags() (tags []string) {
	var m = map[string]bool{}
	for _, issue := range i {
		for _, tag := range issue.Tags {
			m[tag.Name] = true
		}
	}
	for tag := range m {
		tags = append(tags, tag)
	}
	sort.Strings(tags)
	return
}

func (is Issues) Assigned(assigned bool) (n int) {
	for _, i := range is {
		if assigned == (i.Handler.Name != "") {
			n += 1
		}
	}
	return n
}

func (i *Issue) IsHandled() bool {
	return i.Handler.Name != ""
}

func (i Issues) TargetVersions() (targets []string) {
	var m = map[string]bool{}
	for _, issue := range i {
		m[issue.TargetVersion.Name] = true
	}
	for t := range m {
		targets = append(targets, t)
	}
	sort.Strings(targets)
	return
}

func (i Issues) Categories() []string {
	var m = map[string]bool{}

	for _, issue := range i {
		m[issue.Category.Name] = true
	}

	var r = []string{}
	for c := range m {
		r = append(r, c)
	}
	sort.Strings(r)
	return r
}

func (i Issues) ByCategory(cat string) (issues Issues) {
	for _, issue := range i {
		if issue.Category.Name == cat {
			issues = append(issues, issue)
		}
	}
	sort.Sort(sort.Reverse(ByHandlerAndId(issues)))
	return issues
}

func (i Issues) ByCategoryAndTarget(cat, tar string) (issues Issues) {
	for _, is := range i {
		if is.TargetVersion.Name == tar &&
			is.Category.Name == cat {
			issues = append(issues, is)
		}
	}
	sort.Sort(sort.Reverse(ByHandlerAndId(issues)))
	return
}

// Follow the example for multiSort in https://pkg.go.dev/sort

type lessFunc func(i1, i2 *Issue) bool

type multiSorter struct {
	issues Issues
	less   []lessFunc
}

func (ms *multiSorter) Len() int {
	return len(ms.issues)
}

func (ms *multiSorter) Sort(issues Issues) Issues {
	ms.issues = issues
	sort.Sort(ms)
	return ms.issues
}

func (ms *multiSorter) Swap(i, j int) {
	ms.issues[i], ms.issues[j] = ms.issues[j], ms.issues[i]
}

func (ms *multiSorter) Less(i, j int) bool {
	p, q := &ms.issues[i], &ms.issues[j]
	var k int
	for k = 0; k < len(ms.less)-1; k++ {
		less := ms.less[k]
		switch {
		case less(p, q):
			return true
		case less(q, p):
			return false
		}
	}
	return ms.less[k](p, q)
}

var severityOrder = map[string]int{
	"block":   0,
	"crash":   1,
	"major":   2,
	"minor":   3,
	"text":    4,
	"trivial": 5,
	"tweak":   6}

var lessFuncs = map[string]lessFunc{
	"Category":   func(i1, i2 *Issue) bool { return strings.Compare(i1.Category.Name, i2.Category.Name) < 0 },
	"Assignment": func(i1, i2 *Issue) bool { return strings.Compare(i1.Handler.Name, i2.Handler.Name) < 0 },
	"Handler":    func(i1, i2 *Issue) bool { return strings.Compare(i1.Handler.Name, i2.Handler.Name) < 0 },
	"Target":     func(i1, i2 *Issue) bool { return strings.Compare(i1.TargetVersion.Name, i2.TargetVersion.Name) < 0 },
	"Id":         func(i1, i2 *Issue) bool { return i1.Id < i2.Id },
	"Severity": func(i1, i2 *Issue) bool {
		s1, ok := severityOrder[i1.Severity.Name]
		if !ok {
			return true
		}
		s2, ok := severityOrder[i2.Severity.Name]
		if !ok {
			return false
		}
		return s1 < s2
	},
}

func OrderedBy(fields ...string) *multiSorter {
	m := &multiSorter{}
	for _, field := range fields {
		fn, ok := lessFuncs[field]
		if !ok {
			log.Printf("unknown field to order by: %s\n", field)
			return nil
		}
		m.less = append(m.less, fn)
	}
	return m
}